In the summer of 1942, after already having lost the Battle of Britain, the Luftwaffe adopted a more technological stealth-like approach; they would use groups of bombers flying at very low altitudes, making them difficult to detect, or instead at a more medium altitude using cloud cover. As losses became increasingly heavier, the German strategists chose to use another form of attack, without any fighter escorts; high altitude reconnaissance bombers flying with pressurised cabins and ultra- powerful turbocharged engines. With a wingspan superior to that of a Lancaster, these aeroplanes were capable of flying at very high altitude of up to 45,000ft. Although these attacks were not widespread, they did have very targeted objectives. The British called them ‘hit and run raiders’, ‘sneak raiders’ or just simply ‘raiders’.
Surprised by these attacks, the RAF decided to thwart the Luftwaffe by modifying its planes and entrust the Special Flight Squadron with specifically intercepting these missions at high altitude. One particular pilot called upon was Emmanuel Galitzine, a veteran flying ace of the Battle of Britain, a direct descendant of Catherine the Great and who would later provide vital support to the Resistance Movement .
For these new kind of missions, Galitzine would undergo special high altitude training in an airtight de-pressurized box simulator at Farnborough, where he learnt that any movements he made he had to do slowly due to the pressure, and he was even provided with a heated flying suit for the operation.
In August 1942, having already taken part in the Norwegian and French campaigns, the Luftwaffe moved Horst Götz and Erich Sommer to Beauvais and they were then soon posted to Casablanca. With their reconnaissance Ju 86R ‘T5+PM’ of Höhenkampfkommando der Versuchsstelle für Höhenflüge (Staffel 14/KG 6), armed with a single 250kg bomb, the two airmen carried out a series of precision bombardments. Their targets were Aldershot on 24 August, Luton on the 25th and Bristol on the 28th, with this last mission causing the deaths of a number of civilians following an error in navigation.
On 12 September 1942, Götz and Sommer prepared for a bombing raid on Cardiff. They took off from Beauvais at 08:25hr and as they gained altitude, turned towards Normandy, flying directly over Rouen. At 08:53hr they were picked up by British radar at 26,000ft above Rouen, then at 42,000ft over Fecamp before crossing the Channel. At 09:47hr the Ju 86R sent a message to Caen, signalling the presence of two British ships ten miles south of Portland Bill. The message – and consequently the aeroplane – were immediately detected by RAF listening post Y, who immediately sent two Spitfire Vs from 421 Squadron. They spotted the Junkers, but could not intercept as the altitude it was flying at was too high.
At the same time, after the German plane had crossed the French coast at 09:27hr, a specially modified Spitfire IX BF273 of the Special Flight Squadron, piloted by Emanuel Galitzine took off from RAF Northolt. When the Junkers arrived on the outskirts of Salisbury, an astonished Erich Sommer saw the Spitfire and quickly informed Horst Götz that they had been intercepted by an aircraft flying at a greater altitude to them and continuing to climb.
Gatlitzine’s gun is jammed
Immediately, Götz and Sommer put on their oxygen masks and partially depressurised the cabin. They dropped their singular bomb in the Salisbury area and tried to escape towards the sea. It was now 10:00hr. Götz injected the fuel with nitrogen peroxide in order to give more power to the engines and give his pursuer the smallest target to aim at. Galitzine, who was less than 200m behind, opened fire. After the first salvo, his port side gun jammed, but the starboard gun continued to fire. It’s failure caused the Spitfire to spin, and in righting itself it crossed through the vapour trails of the German plane, which still contained the residue of the combustion fuel, causing Galitzine’s windscreen to steam up and the pilot to lose sight of his target.
Götz escaped. Galitzine climbed again and, his windscreen having cleared, plunged towards the bomber firing with his starboard gun. He manoeuvred his aircraft with great care, remembering the instructions given to him in training. However the same problem remained; as he passed through the vapour trails of the German aircraft, the windscreen fogged up a second time, forcing Galitzine to disengage once more. This would happen twice more.
Götz dived, thinking that he had been hit and Galitzine, unable to return to his base due to being short on fuel, had to land at Tangmere. It was 10:45hr. In the middle of the dive, one of the Junker’s engines had stopped working, but it started again at 12,000ft.
At 12:06hr, the Junkers landed at Caen-Carpiquet and the crew discovered one of the wings had been split from one side to the other by a shell, but luckily no vital parts had been damaged. On their return to Beauvais, the Luftwaffe experts would immediately take on board the lessons learned from this interception and the sorties by these raiders would cease from that day onwards.
This was the first and last interception at such high altitude by any air force in the Second World War and the two German pilots were rewarded with prestigious medals.
Exceptional machines for exceptional pilots
Originally designed as a commercial aeroplane, then transformed into a bomber, the Junkers 86 flew for the first time in 1934. The Luftwaffe received the planes in February 1936 and the first commercial planes equipped with ten seats were delivered to Swissair in April of the same year. Afterwards they were sold to Sweden, South Africa, Chile and Portugal.
With its twin 600 horsepower Jumo 205 diesel engines , its cruising speed was around 300km/h. Five Ju 86Ds flew with the Condor Legion in Spain, but proved to be disappointing. In 1939 an improved version was made, with an increased wingspan of 32m, 1000 horsepower Jumo 207 engines and a pressurized cabin, it was capable of flying at 45,000ft with a speed approaching 400km/h.
If the power of the engines had been practically doubled in these five years, their design remained the same: six face-to-face vertical cylinders with two pistons, coupled by two crankshafts, one above, the other below, coupled by gear sets. The upper pistons revealed the inlet, the lower the exhaust valve and were powered by a two stage turbocharger. The initial 105mm bore had been increased to 110mm, then 160mm, increasing the volume from 16.6 to 18.3 litres. These Jumo 207B engines weighed 650kg and had the lowest consumption of equal-powered piston engines at the time.
For the missions in August and September 1942, the ‘T5+PM’ carried a single 250kg bomb and dropped it using a precision bombsight gyro, ‘Lotfe 7E’, which replaced the ‘X-Geräte’.
The legendary aeroplanes of the Spitfire family are more well known. To thwart the attacks from the ‘raiders’, Supermarine first developed a Mk VI with elongated wings: 40ft 2in. Then a Mk VII with a bi-turbocharged Merlin 61 engine and pressurised cabin and finally, in 1942, a Mk IX, which represented a synthesis of the proceeding developments, but curiously, without pressurisation or elongated wings. It was, however, equipped with a tracking radar. In order to be lighter, and therefore faster, this Spitfire was only armed with two 20mm Hispano guns, the machine guns and armour having been removed and the metal helix being replaced by a lighter wooden one. These modifications led to a weight loss of 450lbs.
Emmanuel Galitzine received his BF273 Mk IX on 10 September 1942 at Northolt, where the RAF had created the Special Fight Squadron. On the same day, he carried out a second flight in order to test the guns. He reported that the plane was particularly agreeable to fly and just after these test flights, he took it into action.
Following the usual practice, as soon as Spitfires were available with powerful Griffon 61 series engines, the PRUs made their demands. Still more altitude and a higher top speed suited their needs admirably, but they wanted the advantage of a pressure-cabin which allowed pilots to safely fly the aircraft at altitudes in excess of 40,000 ft. Units had experienced a taste of this with the limited production run PR X (based on the F VII), and they were keen to get hold of the new PR XIX, which evolved from the Spitfire XIV. Boasting a greater range than the PR XI and the cockpit conditions of the PR X, the aeroplane would be broadly similar to the Mk XIV but with modified PR XI wings (more fuel tanks were added) and other modifications associated with the installation of cockpit pressurisation. In general, the latter system was the same as that installed in the Spitfire VII, except that for this aircraft the air intake and blower were on the port side of the engine rather than to starboard.
The camera installation in the PR XIX was broadly similar to that found in the PR XI, with a ‘U’ fitting provided for either two ‘fanned’ or a single F52 36-inch vertical camera, two ‘fanned’ F52 20-inch vertical or two ‘fanned’ F24 14-inch vertical cameras and one F24 14-inch or 8-inch oblique. In addition, the wing camera installation as used on later PR XIs could be fitted in place on the inter-spar fuel tanks.
The all-up weight of the PR XIX was 7,500 lbs, and with its overall PR blue finish and no guns, the aircraft looked the last word in smooth, purposeful efficiency. Little wonder, then, that the PR XIX was the fastest Spitfire of them all with a top speed of 460 mph – an increase of 100 mph over its elder brother, the Mk I.
In Soviet and Russian habit, bomber aircraft have been divided into two basic categories. Tactical, or so-called Frontal, bombers were tasked with attacking targets located in the operational-tactical depth of a Front, in other words at ranges beyond the reach of fighter- bombers. Strategic bombers, classed as long-range and, later, intercontinental, were designed to attack targets beyond the boundaries of one or more theatres of military operations. The ‘frontal’ bomber of the 1970s was the Su-24, whose nominated successor is the Su-34. As with ‘Ilya Muromets’, Su-34 betrays some peculiarly Russian characteristics. The robust undercarriage allows the use of unsurfaced runways. The elegant nose section contains a side-by-side cabin for the two crew members; the cabin is armoured, with up to 17mm of titanium to give protection against conventional antiaircraft fire at low levels. Similar armour protection is also disposed around the fuel tanks and engines. In a unique provision for long-range flight, the cabin is of such dimensions that the crew can walk about upright inside it; it is equipped with a toilet, and with a level of pressurisation that allows the crew to work unmasked.
The Su-34 long-range fighter-bomber (istrebitel bombardirovshchik) is a sophisticated derivative of the Su-27. Carrying an 8 tonne warload, it has a combat radius of 1,130km at low level and a maximum unrefuelled ferry range of 4,500km. Practical maximum range with one air-to-air refuelling is a staggering 7,000km.
Due to its carefully shaped nose, which blends elegantly (and quite stealthily) into the canard foreplane and wing leading edge, the Su-34 has acquired the unofficial nickname of ‘Platypus’. Armament on 10 external stores pylons (under each intake duct, on each wingtip, three under each wing) can be Kh-31A/P (AS-17 ‘Krypton’) ASMs under ducts, R-73A (AA-11 ‘Archer’) AAMs on wingtips; a 500kg laser-guided bomb inboard, TV/laser-guided Kh-29 (AS-14 ‘Kedge’) ASM on central pylon and RVV-AE (R-77; AA-12 ‘Adder’) AAM outboard under each wing.
The Su-34 was supposed to replace all in-service Su-24s by 2005, although this timetable now appears highly unlikely; reconnaissance and EW versions are reportedly under development. Its side-by-side cockpit has formed the basis of the proposed Su-30-2 long-range interceptor and the Su-33KUB carrier combat trainer. From 2005 it is intended to fit Su-34 with AL-41F engines equipped with thrust vectoring.
Compared with the Su-27, the Su-34 possesses a completely new and wider front fuselage containing two seats side by side; wing extensions taken forward as chines to blend with the dielectric nose housing nav/attack and terrain-following/avoidance radar; deep fairing behind wide humped canopy; small foreplanes; louvres on engine air intake ducts reconfigured; new landing gear; broader-chord and thicker tailfins, containing fuel; no ventral fins; and a longer, larger diameter tailcone. This has been raised and now extends as a spine above the rear fuselage to blend into the rear of the cockpit fairing. It houses at its tip a rearward-facing radar to detect aircraft approaching from the rear. The landing gear is retractable tricycle type; strengthened twin nosewheel unit with KN-27 wheels, tyre size 680x260mm, farther forward than on Su-27 and retracting rearward; main units have small tandem KT-206 wheels with tyres size 950x400mm, carried on links fore and aft. Twin cruciform brake-chutes repositioned in spine to rear of spine/fairing juncture.
The power plant is two Saturn/Lyulka AL-31F turbofans; each 74.5kN (16,755 lb st) dry and 122.6kN (27,557 lb st) with afterburning. Later, two AL-31FM or AL-35F turbofans, each 125.5-137.3kN (28,220-30,865 lb st) with afterburning. Additional fuel is housed in the tailfins. Retractable flight refuelling probe beneath port windscreen.
Accommodation for the two crew is side by side on K-36DM zero/zero ejection seats. Access to the cockpit is via a built-in extending ladder to a door in the nosewheel bay. The area is protected with 17mm of titanium armour (the total weight of armour plating to protect the cabin, engine bays and fuel tank area is 1,480kg). The dual-control cabin is uniquely spacious for an aircraft in this class, and is designed to ensure maximum crew comfort and efficiency on extended missions. Cabin height and layout allows the crew to stand at full height and move around freely, to visit their toilet and galley installed inside the deep fuselage section aft of the cockpit. At altitudes up to 10,000m the cabin is pressurised to 2,400m, which allows the crew to operate unmasked. The avionic suite includes Leninetz multifunction phased-array radar with high resolution; and a rearward-facing radar in tailcone. Instrumentation is by MFDs. There is a self- defence internal ECM fit. Su-34’s armament consists of one 30mm GSh-301 gun, as in the Su-27. Twelve pylons for high-precision self- homing and guided ASMs and KAB-500 laser-guided bombs with ranges of 135 n miles (250km; 155 miles); R-73 (AA-11 ‘Archer’) and RVV-AE (R-77; AA-12 ‘Adder’) AAMs. Believed to be the principal platform for Vympel’s rearward-firing R-73.
Su-34M modernised version will feature a new electro-optical infrared targeting pod, a Kopyo-DL rearward facing radar that can warn the pilots if missiles are approaching, combined with automatic deployment of countermeasures and jamming.
The Russian Air Force Su-34 modernization program, also referred to as Su-34M, is aimed at making the Su-34 platform more survivable in the 2020s environment. So far, the development effort focuses on the Tarantul electronic warfare (EW) system that will render the aircraft or a group of aircraft immune to detection by hostile radars as well as improved performance avionics that could help improve flight qualities. Another item that may be integrated into the Su-34M is a laser jamming system to blind infrared guided missiles and electro-optical sighting systems. The Su-34M weapon system may include a new modification of the Kh-35 anti-ship missile (Kh-35UE) and a new generation of aero ballistic missiles. The modernization program is slated to begin before the end of 2018 with the Su-34M cleared out for operational deployment by 2020.
The sun shone brightly in the Panama sky as the fighter planes from the aircraft carrier Saratoga (CV-3) roared aloft as part of fleet exercises off the coast of the Central American nation. A few days earlier these same planes had launched a surprise “attack” against the Panama Canal that foreshadowed the independent operations of carrier task forces during World War II. On this day, they were part of a mock fleet engagement, with fighter planes escorting bombing and torpedo aircraft. “Climbed so high we near froze to death [and] cruised over to the enemy [battle] line where we discovered all the Lexington planes below us,” wrote Lieutenant Austin K. Doyle of Fighting Squadron (VF) 2B. With the benefits of altitude and surprise, ideal for fighter pilots ready to do battle, Doyle and his division dove into the “enemy” planes, twisting and turning in dogfights. “When we broke off we rendezvoused . . . [and] strafed every ship in the fleet. . . . No other plane came near us.”
The events of a February day in 1929 described above occurred in the midst of a watershed era in naval aviation, the interwar years bringing a host of momentous advancements on multiple levels. From a technological and operational standpoint, none were as important as the aircraft carrier and the tactical and strategic implications of this new weapon of war. Arguably, the key element of the carrier’s success was its main battery in the form of the aircraft that launched from its decks, the unparalleled progress made in the design and operation of carrier aircraft providing the foundation for the flattop’s success during World War II. Similar progress marked other areas of naval aviation as well. Such was the lasting influence of interwar aircraft development that Lieutenant Doyle, who as a Naval Academy plebe during 1916–1917 served in a Navy with just fifty-eight aircraft of assorted types, could in 1929 write of a carrier strike against the Panama Canal and, later in his career as a carrier skipper, order planes designed on drawing boards of the 1930s to attack Japanese-held beachheads and strike enemy ships over the horizon.
On the day World War I ended, the U.S. Navy’s inventory totaled 2,337 aircraft, including heavier-than-air and lighter-than-air types. While this is an impressive total, given the aforementioned aircraft total of fifty-eight when America entered World War I, the number is deceiving. It is true that flying boats built by the Curtiss Aeroplane and Motor Company operated extensively from overseas coastal bases in the antisubmarine role. Yet, when it came to combat types flown at the front, the majority of naval aviators who deployed overseas trained and logged their operational missions in the cockpits of foreign-built airplanes. As the U.S. Navy developed its plan for aircraft production, the realization of the superiority of foreign designs was apparent to, among others, Commander John H. Towers, the Navy’s third aviator, who before U.S. entry into the war had observed firsthand operations of British aircraft during a stint in England as assistant naval attaché. Even after the signing of the Armistice, foreign types retained their importance to the U.S. Navy’s operations. With overseas observers having witnessed the launching of wheeled aircraft from flight decks built on board British ships, aircraft like Sopwith Camels, Hanriot HD-1s, and Nieuport 29s were procured for use in Navy experiments flying landplanes from temporary wooden platforms erected atop the turrets of fleet battleships. Ironically, the performance of these aircraft, built in the factories of England and France, proved a key factor in the shaping of the interwar aircraft building program.
Indeed, if there was one driving force behind the development of aircraft for the U.S. Navy during the 1920s and 1930s, it was the realization of the importance of shipboard aircraft to naval aviation operations. While this had been on the minds of naval aviation personnel from the beginning—among the earliest experiments conducted were the testing of catapults for launching aircraft from ships—most naval aviators were initially wedded to seaplanes. Upon arriving in Pensacola, Florida, to establish the Navy’s first aeronautical station there in January 1914, Lieutenant Commander Henry Mustin wrote to his wife of the difficulties of finding a suitable site for an airfield from which to operated landplanes and dirigibles: “Personally, I don’t approve of the Naval flying corps going in for those two branches because I think they both belong to the Army.” This philosophy would guide aircraft operations during naval aviation’s first decade and beyond, with naval aviator training and operations centered on seaplane operations.
British experience in World War I, namely the operation of wheeled-aircraft from ships, coupled with the aforementioned experiments on U.S. Navy battleships carried out during winter maneuvers at Guantanamo Bay, Cuba, in 1919, prompted a shift in thinking. Weighed down by pontoons, floatplanes simply could not compare with landplanes when it came to speed and maneuverability. Also, ships operating floatplanes, while they could launch them relatively quickly, had to disrupt operations to come alongside a returning aircraft and crane it back aboard. The aircraft carrier, with a deck devoted to the launching and recovery of aircraft, offered the most promise of maximizing the potential of aircraft in fleet operations.
By 1927, three aircraft carriers—Langley (CV-1), Lexington (CV-2), and Saratoga (CV-3)—had been placed in commission, their presence giving naval aviation heretofore unrealized capabilities in fleet operations and a potential as offensive weapons at sea or against land targets. “The value of aircraft acting on the defensive as a protective group against enemy aircraft is doubtful unless it is in connection with an offensive move,” wrote naval aviator Commander Patrick N. L. Bellinger in his Naval War College thesis in 1925.
The most effective defensive against air attack is offensive action against the source, that is enemy vessels carrying aircraft and therefore, enemy aircraft carriers, or their bases and hangars on shore as well as the factories in which they are built. The air force that first strikes its enemy a serious blow will reap a tremendous initial advantage. The opposing force cannot hope to surely prevent such a blow by the mere placing of aircraft in certain protective screens or by patrolling certain areas. There is no certainty, even with preponderance in numbers, of making contact with enemy aircraft, before they have reached the proper area and delivered their attack, and there is no certainty even if contact is made, of being able to stop them.
Nine years later, the Navy’s war instructions for 1934 emphasized the importance of seizing the offensive during a fleet engagement. “If the enemy aircraft carriers have not been located, our fleet is in danger of an air attack. In this situation, enemy carriers should be located and destroyed,” the document read. It further stated that if enemy carriers had been located, either with their aircraft on board or their strike groups having been launched, U.S. carrier planes would “vigorously” attack them, “destroy[ing] their flying decks.”
This realization of the threat of enemy air power in a fleet action stimulated tactical thought, which in turn influenced the design of the planes tasked with delivering the blows against enemy carriers. Initially, it was conventional wisdom that torpedoes would be the most effective method of attack against enemy ships, but whether an aerial torpedo or a bomb, the struggle facing aircraft designers was developing aircraft that could carry the weight of the ordnance without compromising too much in the way of speed, maneuverability, and range. The first successful torpedo plane design introduced into fleet service was Douglas Aircraft Company’s DT, which was important in more than one respect. First, it was the maiden military plane produced by the company, symbolizing the emergence of a postwar aircraft manufacturing base marked by the opening of such companies as Douglas and Grumman Aircraft Engineering Corporation. These firms, founded after World War I, joined such wartime entities as the Curtiss Aeroplane and Motor Company, Boeing Company, Glenn L. Martin Company, and the Naval Aircraft Factory—the latter a Navy-owned center for manufacturing and testing of airplanes—in meeting the demands of the Navy’s aircraft programs. Second, due to the weight of aerial torpedoes, while earlier torpedo plane designs were twin-engine ones that were unsuitable for carrier use, the single-engine DT was capable of shipboard operations and of carrying a payload of 1,835 pounds. In fact, on 2 May 1924, a DT-2 version of the design carrying a dummy torpedo successfully catapult launched from Langley anchored at Naval Air Station (NAS) Pensacola, Florida. Finally, the DT pointed to the future in its composition, the traditional wood and fabric used in aircraft, while still present, accompanied by sections of welded steel.
Following the DT into production was Martin’s T3M/T4M torpedo planes (versions were also built by Great Lakes with the designation TG), which boasted a higher speed than the DT and could carry versions of the Mk-VII torpedo that was in the Navy’s weapons arsenal during the late 1920s. Its introduction coincided with the first significant involvement of aircraft carriers in fleet exercises, which revealed much about the employment of torpedo planes. Fleet pilots all too quickly found that the operational parameters of their torpedoes left much to be desired, any hope of a successful attack necessitating that the weapon be dropped at an altitude of no more than twenty-five feet with the aircraft flying at a maximum speed of eighty-six miles per hour. Malfunctioning torpedoes were the norm rather than the exception, and the survivability of torpedo planes flying “low and slow” was questionable. Noted a section of the Aircraft Squadrons, Battle Fleet document “Aircraft Tactics—Development of” dated 3 February 1927: “Even with anti-aircraft gunfire in its present underdeveloped stage, torpedo planes cannot hope to successfully launch [an] attack from 2,000 yards and less.” By 1930, there were serious questions as to the wisdom of operating torpedo planes at all.
The introduction of the Mark XIII torpedo held enough promise for the continuation of the torpedo mission, the weapon capable of being launched at a range of 6,300 yards from altitudes of between 40 and 90 feet and at a speed of 115 mph. The weapon’s weight of 1,927 pounds mandated the introduction of a more capable torpedo plane, the Navy selecting another Douglas design, the TBD Devastator. First flown in 1935, the TBD was cutting edge for its era given the fact that it was a monoplane of all-metal construction with a top speed of over 200 mph. It would be upon the wings of the TBD that torpedo squadrons went to war in 1941 and 1942.
Developing alongside airborne torpedo attack as an element of naval aviation’s offensive arsenal was aerial bombing. Before World War I and in the years immediately following, battleship officers remained skeptical of the ability of an aircraft to sink a capital ship with bombs. Though bombing tests conducted by Army and Navy airplanes against antiquated U.S. ships and captured German vessels during 1921 proved a success in the damage they inflicted, the fact that the target ships were at anchor with no anti-aircraft defenses left many Navy officers skeptical. Yet, as the first decade of the 1920s progressed, bombing offered increasing promise. “The relative merits of the torpedo plane and the bombing plane has [sic] been a much mooted question recently,” Chief of the Bureau of Aeronautics Rear Admiral William A. Moffett told an audience at the Army War College in 1925. “Potentially, the aircraft bomb is, I believe, the most serious menace which the surface craft has to face at the present time.” The following year, operations in the fleet focused on a particular type of bombing attack that offered the best chance to make Moffett’s potential menace a real one. On an October day off the coast of San Pedro, California, sailors on the decks of the battleships of the Pacific Fleet heard the whine of aircraft engines and spotted dark specks diving toward them. What they saw and heard were F6C Hawks of Fighting VF Squadron 2 making a simulated attack, the pilots positioning their planes in steep dives as they roared down on their targets. The event marked the first fleet demonstration of the tactic of dive-bombing, and less than two months later squadrons of Aircraft Squadrons, Battle Fleet completed their first dive-bombing exercise.
As was the case with the development of torpedo aircraft, the evolution of bomber designs during the interwar years was in part driven by the increasing weight of the ordnance, their reason for being. Yet, most of the aircraft initially filling the “light bombing” role were not employed solely in that mission, the Bureau of Aeronautics as late as 1927 issuing the opinion that there was no need for a specialized aircraft for that task alone. Four years later the air groups in Lexington and Saratoga did not even include a bombing squadron, each carrier instead embarking two fighting squadrons with one devoted to the fighting mission and one to light bombing. Even the aircraft considered the first Navy design built specifically for dive-bombing, the Curtiss F8C, was a dual mission aircraft that operated in the fleet as a fighter bomber.
During the prewar years the fleet would never divest itself of using a multi-mission aircraft as a dive-bomber, but during the early 1930s the Bureau of Aeronautics issued requests for proposal for a new classification of aircraft called the scout-bomber to equip carrier-based scouting and bombing squadrons. This aircraft would fulfill the missions outlined in the war instructions of attacking enemy surface ships and scouting tactically. Among naval aircraft, the scout-bombers designed in the decade preceding World War II were among the most technologically advanced. The SBU was the first capable of exceeding 200 mph, its wings reinforced to handle the stress of steep dives carrying a 500-pound bomb, while the BF2C-1 Goshawk possessed an all-metal wing structure that made it even more durable in a dive. The SB2U Vindicator, ordered in 1934, was the sea service’s first monoplane scout-bomber. However, the greatest developments came with the Northrop BT-1 and the SBD Dauntless. The former, delivered in 1937, incorporated unique split flaps, the upper and lower flaps opening when the airplane was in a dive. When flight tests revealed extreme buffeting in the horizontal stabilizer, engineers added holes to the flaps, which remedied the problem and in dive-bombing runs slowed the aircraft and made it a stable bombing platform. This technology carried over to Douglas Aircraft Company’s SBD Dauntless, which boasted a top speed of 256 mph, could carry a 1,000-pound bomb, and had a maximum range of 1,370 miles in the scouting configuration. Enhancing the capabilities of these aircraft as dive-bombers was equipment such as telescopic sights and a bomb crutch, the ladder swinging ordnance away from the fuselage during a dive so that falling bombs did not strike the aircraft’s propeller.
In comparison to dive-bombers and torpedo planes, fighter aircraft had a sound foundation upon which to build during the interwar years, air-to-air combat having advanced more during World War I than other arenas of air warfare. Fighters provided cover for bases and ships against enemy air attack and protected bombing and torpedo planes en route to bomb enemy targets, their missions also including clearing the skies of enemy fighters and shooting down enemy scouting planes to deny information to enemy commanders. In short, on the wings of fighter planes rested the responsibility of gaining control of the air and maintaining air superiority, the ideal characteristics for aircraft tasked with this mission being speed, rate of climb, and maneuverability. These characteristics were greatly enhanced in naval aircraft by the introduction of air-cooled engines, embodied by the Pratt & Whitney Wasp. Unencumbered by a radiator that was standard on water-cooled engines, the Wasp was lighter, the savings in weight translating into improved performance. Endurance tests also revealed that air-cooled engines were more reliable, which was appealing for naval aircraft that operated over open ocean far removed from land bases.
As mentioned above, Navy fighters of the interwar era were viewed as multi-mission platforms, as evidenced by the fact that it was fighters that delivered the first successful fleet demonstration of a dive-bombing attack. The Bureau of Aeronautics, in issuing specifications to aircraft companies for the design of new fighter planes, routinely included parameters for the aircraft in the bombing role. As tactics developed during the 1920s and 1930s, however, air-minded officers came to the realization that saddling fighters with a bomb diminished their ability to provide air superiority. As Rear Admiral Harry E. Yarnell commented in 1932 during his tour as Commander, Aircraft Squadrons, Battle Force, “It is becoming increasingly evident that if the performance of fighters is to be improved . . . bombing characteristics of fighters must be made secondary to fighting characteristics.”
Yarnell’s letter coincided with the emergence of the first fighter designed by the relatively new Grumman Aircraft Engineering Corporation, the FF-1. Delivered in 1933, the airplane boasted features new to Navy fighters, including an enclosed cockpit canopy, an all-metal fuselage, and retractable landing gear. Though its forward fuselage was bulbous in order to house the latter, the FF-1 had a top speed of 207 mph, this attribute becoming readily apparent to a U.S. Army Air Service squadron commander, who upon seeing one of the “Fifis” during a tactical exercise over Hawaii in 1933 decided to make a run on it. “Great was his amazement when his dive upon the innocent looking target failed to close the range.” One other aspect of the FF-1’s design was that it was a two-seater, with room for a pilot and observer, an arrangement more in line with torpedo and bombing planes. This fact sparked a debate among fighter pilots over the direction of design of future aircraft. In a 1935 memorandum to the Chief of the Bureau of Aeronautics, the commanding officer of VF-5B noted the two-seat fighter’s superiority in escorting strike groups was possible because of the observer’s ability to scan the skies for enemy aircraft and proclaimed it less vulnerable to diving attack by enemy fighters for the same reason. The VF-5B skipper argued that the two-seater was equal to or superior to the single-seater in all tactical missions required of fighter aircraft. Conceding the general advantage of smaller, single-seat fighters in speed and maneuverability, he concluded that in naval warfare control of the air was obtained not by air-to-air superiority over enemy aircraft formations, but by knocking out the carriers from which the enemy planes operated. “In this the superior characteristic of the single-seater fighter can play little or no part.”
A tactical board convened by Commander, Aircraft Squadrons, Battle Force issued a report on the issue the following January, defining a fighter plane as a “high speed weapon of destruction against other aircraft.” The board criticized the dismissal of this fundamental mission of Navy carrier fighters, writing that the VF-5B commander’s report “gives undue importance to secondary fields of employment . . . emphasizing the suitability of the airplane for a function which is not one for which a VF [fighter plane] is properly suited.” The board concluded that “present VF aircraft in service are of practically no value as VF. They lack either necessary speed superiority over other types or necessary offensive armament, or both.”
This quest for speed would endure, with Grumman following up the FF-1 with first the F2F and then the F3F biplanes, each faster but limited in capability when compared with the Japanese A6M Zero also under development in the late 1930s (the A6M-2, which was operational in 1940, had a top speed of 331 mph compared to 264 mph for the F3F-3). Throughout the late 1930s the Bureau of Aeronautics initiated requests for proposals to the nation’s aircraft industry for fighter designs that emphasized speed and improved armament. In this approach of casting a wide net, the Navy received a variety of designs. Some, including the unorthodox twin-engine F5F Skyrocket, did not enter production, while others, namely Brewster’s F2A Buffalo monoplane, were put into production, but proved disappointing. The aircraft that emerged as the best that could be placed in production most quickly was Grumman’s F4F Wildcat, a monoplane successor to the company’s earlier biplane fighter designs, which with its super-charged engine achieved a maximum speed of 333.5 mph at an altitude of 21,300 feet and boasted four .50-caliber machine guns for armament. On it would rest the fortunes of Navy and Marine fighter squadrons until 1943.
The aircraft carrier and the airplanes that flew from her deck represented the cutting edge of naval aviation operations of the interwar years, with New York Times reporter Lewis R. Freeman capturing the public’s excitement over the ship’s unique operations in an article written in the aftermath of Fleet Problem IX. “Just about the most spectacular show in the world today . . . is the handling and manoevering [sic] of the great carriers Lexington and Saratoga,” he wrote. “The spectacle of launching and landing planes is fully up to the superlative scale of the ship itself. . . . In the darkness of early morning the effect is heightened by circles of spitting fire from the exhausts and the colored lights of the wings and tail.” However, the foundation upon which the airplane entered naval service was seaplanes and flying boats, and in the immediate postwar years they provided naval aviation’s first real integration with fleet operations.
Established in early 1919, Fleet Air Detachment, Atlantic Fleet, put to sea in exercises with surface forces, part of its operations being flights of wheeled aircraft from improvised decks on board battleships. However, significant attention was also devoted to flying boat operations and their support of surface ships, particularly in the spotting of naval gunfire. “For the first time in the history of the Navy, the actual setting of the sights was, to a large extent, controlled by the officers of the Airboat squadron,” read an air detachment report of 1920. “This marks the beginning of a new era in our naval gunnery.” Success in this role, the spotting of naval gunfire, led to the eventual assignment of detachments of seaplanes to cruisers and battleships as part of cruiser scouting (VCS) and observation (VO) squadrons, respectively. To fill this requirement, a number of aircraft procured by the Navy during the interwar years, including the VE-7, UO/FU, and O2U, could be operated in both the landplane and floatplane configuration. By the time the United States entered World War II, the principal aircraft flying in the scouting and observation roles were the Curtiss SOC Seagull and Vought OS2U Kingfisher, the latter a monoplane of which over a thousand were eventually produced.
Long-range scouting would become the domain of flying boats, the detachment demonstrating their endurance in a lengthy seven-month cruise with the fleet, logging 12,731 nautical miles, some 4,000 of which were in direct maneuvers with the fleet. Meanwhile, in the Pacific, flying boats and seaplane tenders formed Air Force, Pacific Fleet in July 1920, putting to sea for joint fleet exercises that demonstrated the scouting capabilities of Navy flying boats. During the cruise, wartime F-5L flying boats covered a distance of 6,076 miles in operations between California and Central America. Wrote Admiral Hugh Rodman, Commander in Chief, Pacific Fleet, at the conclusion of the exercises, “The scouting work performed by the seaplanes was carried out to a distance of about one hundred and sixty-five miles from the bases and in weather which, except under war conditions, might have caused the commander of the force to hesitate about sending the planes into the air.”
During the late 1920s flying boat operations in the Navy began to stagnate as increasing emphasis and funding was devoted to aircraft carrier development. Though over the course of the ensuing years new designs appeared, they were, in the words of Rear Admiral A. W. Johnson in a paper on the development and use of patrol planes, “of no useful purpose except for training and utility services.” In contrast to the seagoing force that had demonstrated so much the potential of the flying boat in fleet operations in the immediate postwar years, Johnson, who commanded Aircraft, Base Force, noted that “patrol plane squadrons became in reality a shore based force,” with cruising reports of seaplane tenders during the late 1920s and early 1930s proof of the diminished employment of flying boats in fleet operations. Even the Consolidated Aircraft Company’s P2Y, which achieved fame when it equipped Patrol VP Squadron 10F in a record-setting non-stop flight between California and Pearl Harbor, Hawaii, in January 1934, had limitations: “[It] must operate from sheltered harbors, and can do nothing in the way of scouting and bombing that cannot be as equally well done by large land planes operating from established shore bases equipped with good flying fields.” Yet, landplanes for distant overwater flights were the exclusive domain of the Army Air Corps, a 1931 agreement between Army Chief of Staff General Douglas MacArthur and Chief of Naval Operations Admiral William V. Pratt preventing the Navy from operating long-range land-based aircraft.
Johnson’s comments came at a critical juncture for both the development of flying boats and the strategic requirements for their employment in the event of war. By the early 1930s, those officers working on War Plan Orange, the constantly evolving American strategy in the event of war with Japan, had begun to more appreciate the role of air power in a fleet engagement. With ships able to engage at greater distances, advance scouting, particularly in the open expanses of the Central Pacific, could prove a deciding factor between victory and defeat.35 For proponents of patrol aviation, this tactical and strategic requirement for flying boats coincided with the introduction of a plane that represented a tremendous advance in flying boat technology—the PBY Catalina.
With a maze of struts and wires between wings limiting the performance of earlier biplane designs, Consolidated Aircraft Company engineers drew up a flying boat built around a high-mounted parasol wing with minimal struts necessary because of internal bracing; this reduced drag, as did wing floats that retracted once airborne to form wingtips. Despite a gross weight that exceeded that of the P2Y it replaced, the PBY boasted a top speed nearly 40 miles per hour faster than that of the P2Y. Deliveries of the PBY began in 1936, and two years later fourteen Navy patrol squadrons operated the type. “I feel very strongly that when the PBY’s [sic] come into service, the Fleet will begin to realize the potentialities of VP’s [sic] [patrol planes],” wrote Rear Admiral Ernest J. King on the eve of the aircraft’s delivery, “and will begin to demand their services.”
Performance in fleet exercises validated the PBY’s capabilities as a long-range scout. Comments on patrol plane activities in Fleet Problem XVIII held in early 1937 concluded that they were capable of locating an enemy force within a five hundred- to one thousand-mile radius of their bases, night tracking, and high-altitude bombing. “Your patrol planes have certainly changed the whole picture in regard to tactics and even strategy,” Captain W. R. Furlong of the Bureau of Ordnance wrote King. Such was the range that the newly arrived Catalinas could reach; planners of future war games would have to “put the brakes on the patrol planes to keep them from finding out everything long before we could get the information from the cruisers and other scouts.”
The capabilities of the PBY, coupled with fatal crashes, spelled the end of the use of rigid airships as long-range scouts, an idea long championed by Rear Admiral William A. Moffett, the first chief of the Bureau of Aeronautics. However, non-rigid airships, notably of the K-class would prove effective in long-range antisubmarine patrols during World War II.
Not as clear in discussions about patrol aviation was the advisability of using flying boats in a bombing role. There was indeed a precedent in the practice, F-5Ls having participated in the famous 1921 bombing tests against captured German warships and stricken U.S. Navy vessels. In 1934, while serving as Chief of the Bureau of Aeronautics, Rear Admiral Ernest J. King had suggested that flying boats could serve as a first strike weapon in an engagement at sea, their attacks preceding those of carrier planes and surface forces. Correspondence between Captain John Hoover and Admiral Joseph Mason Reeves, the latter Commander in Chief, United States Fleet, the following year illuminated the problems with flying boats operating in this capacity. Umpires in fleet exercises determined that patrol planes would incur heavy losses and inflict insignificant damage to capital ships when used in the strike role, with Hoover pointing to the fact that the slow speeds and low service ceilings of patrol planes then in operation (the Consolidated P2Y and Martin PM) made attacks by them “suicidal.” “The way to utilize patrol planes for attacking must by re-studied from a practical viewpoint.” The introduction of the PBY Catalina (“PB” being the Navy designation for patrol bomber), which incorporated a nose compartment for a bombardier and provision to carry the Norden bombsight, offered more promise when it came to patrol bombing operations. However, as the author of the foremost study of planning for the war against Japan has noted, by 1940 the notion of operating flying boats as patrol bombers had been discounted. Yet, wartime necessity would awaken interest in flying boat offensive operations for the PBY and other flying boat designs of the 1930s, including the PBM Mariner and PB2Y Coronado.
By mid-1941, the year in which naval aviation entered the world’s second global war, the Secretary of the Navy could report a net increase of 82 percent over the previous fiscal year in the number of service aircraft on hand in the Navy’s inventory. His annual report noted emphasis being placed on development of dive-bombing and fighting aircraft of greater power, which was “vindicated in the service reports received from belligerents abroad.” Other technical adaptations based on wartime observations included such equipment as self-sealing fuel tanks and improved armor and firepower. “With the present international situation,” the secretary concluded, “it is imperative that all construction work on ships, aircraft and bases be kept at the highest possible tempo in order that the prospective two-ocean Navy become a reality at the earliest possible date.” The sudden events of the morning of 7 December 1941 shifted this tempo into previously unimagined levels, the events that occurred between that day and September 1945 representing the ultimate test for the technology and tactics that evolved during the previous two decades.
“When war comes,” Captain John Hoover wrote in 1935, “we will have just what is on hand at the time, not planes on the drafting board or projected.” For naval aviation, the combat aircraft flying from carrier decks, fleet anchorages, and airfields when war came had entered service between 1936 and 1940. Fortunately, however, the planes that eventually would replace or complement them were far removed from the drafting board. The prototype of the F6F Hellcat made its first flight just months after the Pearl Harbor attack, while the XF4U-1 Corsair had already demonstrated speeds of over four hundred mph during test flights in 1940. Similarly, prototypes of the SB2C Helldiver and TBF Avenger had already taken to the air by the time the United States entered World War II. And with the coming of war, the mobilization of industry translated into rapid transformation of prototypes into production versions of airplanes ready for combat, with American factories turning out an average of 170 airplanes per day from 1942 to 1945.
How did these airplanes fare in the crucible of combat? A telling statistic is found in an examination of air-to-air combat: During the period 1 September 1944–15 August 1945, the zenith of naval aviation power in the Pacific, in engagements with enemy aircraft, a total of 218 naval carrier–based and land-based fighters were lost in aerial combat, while Navy and Marine Corps FM Wildcat, F6F Hellcat, and F4U Corsair fighters destroyed 4,937 enemy fighters and bombers. Even during the period 1942–1943, when naval aviators flew the F4F Wildcat, which in comparison to the heralded Japanese Zero had an advantage only in its defensive armor and self-sealing fuel tanks, carrier-based and land-based Wildcat pilots splashed 905 enemy fighters and bombers. This came at a cost of 178 Wildcats destroyed and 83 damaged. Comparing the two eras, in all the action sorties flown by naval aircraft during 1942, 5 percent ended in the loss of the aircraft. In 1945, less than one-eighth of 1 percent of all action sorties resulted in a combat loss. While direct comparisons are not possible with other classes of aircraft, a look at the total number of sorties flown against land and ship targets by year is revealing. In the first two years of the war, 19,701 sorties were directed against ship and shore, a figure that for the years 1944–1945 jumped to 239,386!
A key reason for this increase was aircraft development. The carrier Enterprise (CV-6), at sea when the Japanese attacked Pearl Harbor, had none of the same aircraft types on board when she operated off Japan in 1945. The F4U Corsair and F6F Hellcat by that time in the war boasted better top speeds, rate of climb, and performance at altitude than the most advanced versions of the Japanese navy’s Zero fighter. Similarly, the SB2C Helldiver and TBF/TBM Avenger, particularly once technical maladies were corrected in the former, proved to be more than comparable to the aircraft operated by the Japanese in the torpedo and bombing roles. In addition, Japanese aircraft to a great extent suffered from deficiencies in their armor protection, making them more susceptible to being shot down by Allied aircraft and antiaircraft gunners. Even though the Japanese did produce some very capable aircraft as the war progressed—among them the all-metal Yokosuka D4Y Suisei bomber that had a top speed comparable to many fighters and the Kawanishi N1K1-J/N1K5-J Shiden and Shiden Kai fighter, which in the hands of an experienced pilot could be more than a match for an Allied fighter—they appeared in too few numbers to have much effect on the outcome of the war. In addition, due to increasing Allied superiority in material, the successful campaign against Japanese merchant and combat ships, and the increasing conquest of territory, Japanese planes were at a strategic and tactical disadvantage before they even left the ground.
There is more to the story behind the statistics. First, sortie rates and the number of enemy aircraft destroyed rose in direct proportion to the growth of U.S. naval aviation. In 1941 there were 1,774 combat aircraft on hand in the U.S. Navy. By 1945 that figure had grown to 29,125. When the Japanese attacked Pearl Harbor, the Navy had a total of seven fleet carriers and one escort carrier in commission. Between that time and the end of the war, the Navy commissioned 102 flattops of all classes. Then there was the human factor. Imperial Japanese Navy and Army pilots generally remained in combat squadrons until they were killed or suffered wounds that rendered them unable to fly, this policy of attrition steadily reducing the quality of enemy pilots faced as the war progressed. This was apparent as early as late 1942, a Report of Action of Fighting Squadron (VF) 10 in November 1942 noting that the “ability of the enemy VF [fighter] pilots encountered in the vicinity of Guadalcanal is considered to be much inferior to the pilots encountered earlier in the war.” In contrast, experienced U.S. naval aviators rotated in and out of combat squadrons. For example, Lieutenant Tom Provost, designated a naval aviator during the late 1930s, flew fighting planes from the carrier Enterprise (CV-6) during the early months of World War II, including service at the Battle of Midway. His next tour was as a flight instructor, imparting knowledge to fledgling pilots before returning to the fleet in 1944 and 1945 to fly F6F Hellcat fighters off an Essex-class carrier. These naval aviators were well led and well trained. Fighter squadron commanders during the early months of the war, notably Lieutenant Commanders John S. Thach and James Flatley, proved adept at developing tactics to maximize the advantages of their aircraft over those of the enemy while the U.S. Navy’s longtime emphasis on teaching deflection shooting paid dividends in actual combat. The same imparting of lessons learned was standard in other types of squadrons as tactics developed throughout the war.
During World War II, were U.S. Navy aircraft employed in a manner envisioned during the interwar years and how did the ever-changing tactical environment affect the operations of naval aircraft? The answers to these questions provide an important framework in which to assess the history of aircraft development between 1922 and 1945.
Much prewar discussion centered on how naval aircraft could be most effective in a fleet engagement, and concerns expressed at that time about the vulnerability of torpedo planes proved well founded, with carrier-based torpedo squadrons at Midway suffering grievous losses. Despite the fact that even as late as May 1945, experienced carrier task force commander Vice Admiral Marc A. Mitscher still considered the torpedo “the major weapon for use against surface ships,” the number of torpedoes dropped at sea decreased as the war progressed. For carrier-based aircraft and land-based aircraft, during the first year of the war torpedoes accounted for 73 percent and 94 percent, respectively, of the total ordnance expended on shipping by weight. By 1945, those figures had dropped to 16 percent and 0 percent, respectively, and throughout the war only 1,460 torpedoes were dropped by naval aircraft. Factors contributing to these low numbers included the problematic aerial torpedoes in the U.S. inventory early in the war and the focus of carrier strikes in the war’s latter months being increasingly centered on hitting land targets. During 1945 the total tonnage of bombs dropped on land targets by Navy and Marine Corps aircraft was 41,555 as compared to just 4,261 tons of ordnance dropped on ships of all types during the same period.
Dive-bombing lived up to expectations as a tactic that could influence the outcome of a sea battle, a fact demonstrated in dramatic fashion in the sinking of four Japanese carriers at the Battle of Midway. However, as evidenced by the statistic above, as the war moved ever closer to the Japanese home islands, targets for carrier-based dive-bombers were increasingly located ashore rather than afloat, with planes attacking harbor areas, transportation networks, and enemy airfields. It was in the bombing mission that wartime experience shuffled the prewar and early war composition of carrier air groups. Scouting squadrons, which in 1942 were equipped with the same airplane—the SBD Dauntless—as bombing squadrons on board carriers, were eliminated from carrier air groups by 1943. In addition, torpedo planes and fighters increasingly assumed some of the ground attack mission, the latter reawakening the fighter versus fighter bomber debate of the 1930s. Commanders had no choice but to use fighters in the bombing role during 1944 and 1945 when the advent of the kamikazes necessitated that the number of fighter planes in a carrier air group be increased dramatically. By war’s end, their numbers were double that of the combined number of torpedo and scout-bombers. In the fighter-bomber role, naval single-engine fighters from land and ship logged a comparable number of ground attack missions as that of airplanes designed as bombers. However, on these missions they expended primarily rockets and machine gun ammunition. The SBD Dauntless, SB2C Helldiver, and TBF/TBM Avenger proved the mainstay of the bombing mission, the latter aircraft proving to be one of the most versatile naval aircraft of the entire war. The dive-bombers carried 34 percent of all naval aviation’s bomb tonnage, while Avengers delivered 32 percent of the bomb tonnage and launched 29 percent of all rockets.
The employment of fighters in the bombing role was central to the debate about the composition of carrier air groups, the subject of much discussion as the war drew to a close. A 1944 survey of carrier division commanders on the subject revealed a consensus that the majority of airplanes on deck should be fighters, the problematic SB2C Helldiver perhaps influencing calls for fighters to assume a ground attack role in addition to the air-to-air mission. Vice Admiral Mitscher preferred dive-bombers over fighter bombers, telling Captain Seldon Spangler, who was on an inspection tour of the Pacific in 1945, that dive-bombers, even given the inadequacies of the SB2C, were better than the F4U Corsair in the bombing role. Wrote Spangler, “He thought it would be most desirable to get down to two airplane types aboard carriers, one to be the best fighter we can build, the other to be a high performance torpedo dive bomber.” Rear Admiral Gerald F. Bogan concurred to some degree. Although favoring the intensification of dive-bombing for fighting planes, he wrote “Do not emasculate the VF plane.” Interestingly, in production were two airframes that met Mitscher’s requirements, the BT2D (later AD) Skyraider, which combined the torpedo and bombing missions into one attack mission, and a pure fighter in the form of the F8F Bearcat. Interestingly, the F4U Corsair, which, after some technical problems were solved, became an excellent carrier plane and served for years after World War II on the basis of its capabilities as a fighter bomber.
“The Fleet is well satisfied with PBY-5A airplanes for use at Guadalcanal for night reconnaissance, bombing, torpedo attack, mining, etc.,” read an 28 April 1943, report to the Director of Material in the Bureau of Aeronautics. “They are not using these airplanes in the daytime except in bad visibility.” This concise summary of operations in the first part of the Pacific War reveals that in their decision to remove the flying boat from consideration as a long-range daylight bomber, prewar officers were correct about the platform’s capabilities. Action in the war’s early weeks proved the vulnerability of the lumbering PBYs to enemy fighters, with four of six PBYs of VP Patrol Squadron 101 shot down on a 27 December 1941, raid on Jolo in the central Philippines. However, under the cover of darkness, the aircraft proved highly effective in the ground attack mission. As prewar exercises demonstrated, PBYs performed well as long-range scouts, most notably in their locating elements of the Japanese fleet at Midway. Their ability to patrol wide expanses of ocean also made them effective as antisubmarine platforms against German U-boats as well as very capable search and rescue aircraft.
What could not have been foreseen during the 1930s in light of the division of roles and missions between the armed services was the successful operation of long-range multi-engine landplanes in naval aviation. As noted above, the Pratt-MacArthur agreement had given the Army Air Corps exclusive use of long-range land-based bombers to fill their role in coast defense, but with flying boats limited in daylight bombing, the Navy began pressing for the ability to operate multi-engine bombers from land bases. In July 1942 the Sea Service reached an agreement with the Army Air Forces (re-designation of Army Air Corps in 1941) to divert some production B-24 Liberators to the Navy for use as patrol bombers. The first of these airplanes, designated PB4Y- 1s, were delivered to the Navy in August, and the following year, with its focus on the strategic bombing campaigns in Europe and the Pacific, the Army Air Forces relinquished its role in antisubmarine warfare. Other aircraft eventually joined the PB4Y-1 in the patrol bombing role in both the European and Pacific theaters, including a modified Liberator designated the PB4Y-2 Privateer, the PBJ (Army Air Forces B-25) Mitchell, and the PV Ventura/Harpoon.
While the Army Air Forces employed their bombers in primarily in horizontal attacks, which were also carried out by Navy and Marine Corps medium bombers, many Navy crews specialized in low-level bombing, oftentimes dropping on enemy shipping at masthead level. A review of 870 PB4Y attacks against shipping revealed that over 40 percent of them resulted in hits. In addition, they were credited with downing over three hundred enemy planes, the PB4Ys being heavily armed with machine guns. Marine PBJs proved the workhorse of land-based patrol bombers, flying more than half of all action sorties flown. All told, patrol bombers, while flying just 6 percent of naval aviation’s action sorties, dropped 12 percent of all bomb tonnage delivered on targets during World War II.
A number of other operations involving naval aircraft are worthy of discussion in drawing conclusions about the development of naval aircraft through World War II. Radar-equipped aircraft made tremendous strides in operations after dark during World War II, completing some 5,800 action sorties from carriers and land bases. From a total of only 76 attacks (air-to-ground and air-to-air) against enemy targets in 1942, naval aviation night operations grew to include 2,654 nocturnal attacks in 1944. The PBYs would not have been able to have as much of an offensive impact as they did without their night attack capability. Carrier aircraft, despite fears about tying carriers to beachheads in support of amphibious operations, achieved a great deal of success in providing close air support to assault forces, primarily flying from escort carriers. Naval aircraft, including carrier-based ones, proved that they could neutralize land-based air power, with fighter sweeps focusing on enemy airfields on island chains and the Japanese homeland serving the purpose of striking potential attackers at their source. “Pilots must be impressed with the double profit feature of destruction of enemy aircraft,” read a June 1945 memorandum on target selection for Task Force 38 carriers operating off Japan. “Pilots must understand the principles involved in executing a blanket attack. The Blanket Operation is NOT a defensive assignment. It is a strike against air strength.” Finally, in the field of weapons development, the advances like electronic countermeasures equipment to thwart enemy radar and the introduction of high-velocity aircraft rockets (HVAR) made carrier aircraft more capable platforms, the latter yielding positive results particularly in close air support against enemy defensive positions.
In a speech delivered during the 1920s, Admiral William S. Sims remarked, “One of the outstanding lessons of the overseas problems played each year is that to advance in a hostile zone, the fleet must carry with it an air force that will assure, beyond a doubt, command of the air. This means not only superiority to enemy fleet aircraft, but also to his fleet and shore-based aircraft combined.” This statement reflected the essence of naval air power, and it can be argued that during the interwar years all aspects of aircraft development, from design to tactics, supported the drive of naval aviation advocates toward a fleet that reflected this vision. By 1945, at the end of the greatest war the world has ever known, a triumphant flight of hundreds of carrier planes over the battleship Missouri (BB 63) as the instrument of surrender was being signed on her deck was proof that the vision had been realized.
Specifications (Navy Type 97 Flying Boat Model 23 – Kawanishi H6K5)
Allied Codename: Mavis (Transport versions were given the Allied codename “Tillie”)
Type: (H6K1, H6K2, H6K4 & H6K5) Nine Seat Long Range Reconnaissance Bomber. (H6K2-L, H6K3 & H6K4-L) Eight Seat Long Range Troop & VIP Transport with room for up to 18 passengers.
Accommodation/Crew: (H6K5) Pilot, Co-pilot, Bombardier, Navigator, Radio Operator, Flight Engineer and three gunners.
Design: Kawanishi Kokuki Kabushiki Kaisha Design Team led by Yoshio Hashiguchi and Shizuo Kikahura.
Manufacturer: Kawanishi Kokuki Kabushiki Kaisha (The Kawanishi Aircraft Company Limited) at Naruo Mukogun Hyogoken, near Kobe.
Powerplant: (H6K1) Four Nakajima Hikari 2 nine-cylinder air-cooled radials, rated at 840 hp for take-off and 700 hp at 1,200 m. (H6K1 Model 1, H6K2, H6K2-L, H6K3 and H6K4 Model 2-2) Four Mitsubishi Kinsei 43 fourteen-cylinder air-cooled radials, rated at 1,000 hp for take-off and 990 hp at 2,800 m. (H6K4 Model 2-3 and H6K4-L) Four Mitsubishi Kinsei 46 fourteen-cylinder air-cooled radials, rated at 930 hp for take-off and 1,070 hp at 4,200 m. (H6K5) Four Mitsubishi Kinsei 51 or Kinsei 53 fourteen-cylinder radials, rated at 1,300 hp for take-off, 1,200 hp at 3,000 m and 1,100 hp at 6,200 m. All versions of the aircraft used three-bladed metal propellers.
Performance: Maximum speed 190 mph (304 km/h) at 8,000 ft (2440 m) and 239 mph (385 km/h) at 19,685 ft (6000 m); cruising speed 161 mph (260 km/h) at 13,125 ft (4000 m); service ceiling 31,365 ft (9560 m); climb to service ceiling in 13 minutes 23 seconds.
Range: Normal range 3,067 miles (4939 km) on internal fuel with a maximum range of 4,204 miles (6770 km).
Weight: Empty 27,117 lbs (12380 kg) with a maximum take-off weight of 50,706 lbs (23,000 kg). Loaded weight was typically 38,581 lbs (17,500 kg).
Dimensions: Span 131 ft 2 3/4 in (40.0 m); length 84 ft 1 in (25.63 m); height 20 ft 6 3/4 in (6.27 m); wing area 1,829.92 sq ft (170.0 sq m); wing loading 21.1 lbs/sq ft (102.9 kg/sq m); power loading 7.4 lbs/hp (3.4 kg/hp).
Defensive Armament: One 7.7 mm (0.303 in) Type 92 machine-gun in forward turret, one 7.7 mm (0.303 in) Type 92 machine-gun in an open dorsal position, one 7.7 mm (0.303 in) Type 92 machine-gun in each beam blister and one flexible mounted 20 mm Type 99 Model 1 cannon in tail turret.
Disposable Ordnance: Two 17.7″ (44.9 cm) 1,841 lbs (835 kg) Type 91 Mod 2 or 1,872 lbs (849 kg) Type 91 Mod 3 torpedoes or up to a maximum of 4,409 lbs (2000 kg) of bombs attached to the wing support struts. The normal operational bombload would have only been 2,205 lbs (1000 kg).
Variants: H6K1 (4 prototypes), H6K1 Model 1 (3 modified from the prototypes), H6K2 Model 11 (10 aircraft 1938-39), H6K3 (2 aircraft in 1939 completed as VIP transports), H6K4 Model 22 (major production version – 127 aircraft completed between 1939-42), H6K5 Model 23 (36 aircraft completed in 1942), H6K2-L (unarmed transport – 16 completed between 1940-42), H6K4-L (unarmed transport – 20 completed between 1942-43 with another two aircraft being modified from H6K4 airframes in 1942).
History: First flight (prototype) 14 July 1936 by test pilot Katsuji Kondo.
Operators: Japan (Imperial Japanese Navy)
Units: 8th, 801st, Toko and Yokohama (later 802nd) Kokutais.
The air arm of the Imperial Japanese Navy had gained its first experience of large flying boats from the Kawanishi H3K2, or Navy Type 90-11 Flying Boat. This had its beginnings in the British Short Brothers K.F.1 prototype designed for the Japanese navy which, after a first flight on 10 October 1930, was soon sent to Japan where it served as a pattern for four H3K2s, built by Kawanishi under the supervision of a British technical team. This emphasises how, in its early involvement in aviation, the Japanese industry was dependent upon copying the designs of foreign manufacturers. From their study of these designs and the constructional techniques adopted, Japan ‘s young engineers gained valuable experience in a comparatively short time. By the early and mid-1930s they had acquired sufficient knowledge to start the design and development of a number of first-class aircraft.
When, in 1933, the navy considered the moment had come to acquire a larger and more efficient flying boat, Kawanishi was given a specification against which it was required to submit proposals for two alternative designs with three and four engines, identified as the Type Q and R respectively. Unfortunately the proposals were not satisfactory, and in early 1934 the navy issued a revised and more demanding specification, which called for a cruising speed of 137 mph (220 km/h) combined with a range of approximately 2,795 miles (4500 km). This performance (if achieved) would better that of the Sikorsky S-42 flying boat, which had made some important pioneering flights. Kawanishi’s reappraisal of the requirement resulted in a new design, identified initially as the Type S and the work of a team headed by Yoshio Hashiguchi and Shizuo Kikahura, who had both had an opportunity of studying flying boat design at Short Brothers in the UK.
Required to fulfill the roles of bombing, reconnaissance and transport, the prototype had a slender and graceful two-step hull above which was mounted a parasol wing, the wing having a stabilizing float strutted and braced beneath its undersurface just outboard of midspan, and mounting at its leading edge four 840 hp (626 kW) Nakajima Hikari (Splendour) 2 nine-cylinder air-cooled radial engines. The tail unit, strut-mounted high on the rear fuselage, comprised a monoplane tailplane and twin fins and rudders, and for normal operations use the hull provided accommodation for a crew of nine.
First flown on 14 July 1936, the H6K1 prototype in early tests showed a need of hull modification to improve water handling, and the more extended manufacturer’s tests and service trials that followed this work revealed the type to be satisfactory but underpowered. Three more prototypes were ordered, all with Hikari 2 engines originally, but the first, third and fourth of the prototypes were each given four 1,000 hp (746 kW) Mitsubishi Kinsei (Golden Star) 43 fourteen-cylinder air-cooled radial engines before they entered service in January 1938 under the designation Navy Type 97 Flying Boat Model 1. Simultaneously, the type was ordered into production and eventually a total of 215 of all versions were built, the initial H6K2 production model being generally similar to the re-engined prototypes except for minor equipment changes. Armament comprised three 7.7 mm (0.303 in) machine-guns on trainable mounts in bow, power-operated dorsal turret and non-powered tail turret, and up to 2,205 lbs (1000 kg) of bombs could be carried. Two generally similar aircraft, which were equipped to serve specifically as VIP transports had the designation H6K3.
The major production version was the H6K4 which had greater fuel capacity and improved defensive armament comprising four 7.7 mm (0.303 in) machine-guns in bow, two side blisters and open dorsal position, plus one 20 mm cannon in a tail turret. Its powerplant was unchanged initially, but from August 1941 the Kinsei 43 engines were replaced by 930 hp (694 kW) Kinsei 46 fourteen-cylinder air-cooled radial engines which gave better performance at altitude. Final armed military production version was the H6K5 which, generally similar to the H6K4, deleted the open bow gun position and introduced a turret with a single 7.7 mm (0.303 in) machine-gun immediately to the rear of the flight deck, and performance was improved by the installation of uprated 1,300 hp (970 kW) Kinsei 51 or 53 radial engines. In 1939 two H6K2s had been modified to serve as prototypes for an unarmed version for use as a military staff transport and for operation on the long over-water routes of Dai Nippon Koku K.K. (Greater Japan Air Lines).
Following successful testing the company began production of the H6K2-L, based on the early H6K4 with 1,000 hp (746 kW) Mitsubishi Kinsei (Golden Star) 43 engines, and equipped to accommodate 18 passengers. Sixteen of this version, plus two similar aircraft converted from H6K4s, were supplied to Dai Nippon Koku K.K. (Greater Japan Air Lines), being followed by 20 H6K4-L unarmed transports for the Japanese navy; these later aircraft differed by being based on the H6K4, with Kinsei 46 engines, and were provided with additional cabin windows.
The H6K saw early operational service during the Sino-Japanese War, but was used extensively with the outbreak of the Pacific war, the armed versions receiving the Allied codename ‘Mavis’ in 1942, by which time the increasing capability of fighter aircraft ranged against the type was such that it could no longer be deployed in a bomber role. Instead the type found increasing reconnaissance/transport use in areas where comparatively little fighter opposition could be expected, many remaining in service until the end of the war .The unarmed transport versions were given the Allied codename ‘Tillie.’
Kawanishi H6K1 ‘Type S’ Prototypes – The first prototype had a slender and graceful two-step hull above which was mounted a parasol wing, the wing having a stabilizing float strutted and braced beneath its undersurface just outboard of midspan, and mounting at its leading edge four 840 hp (626 kW) Nakajima Hikari (Splendour) 2 radial engines. The tail unit, strut-mounted high on the rear fuselage, comprised a monoplane tailplane and twin fins and rudders, and for normal operations use the hull provided accommodation for a crew of nine. First flown on 14 July 1936, the H6K1 prototype in early tests showed a need to improve water handling, so the forward step was moved back 1 ft 7 11/16 inches (50 cm). The more extended manufacturer’s tests and service trials that followed this work revealed the type to be satisfactory but underpowered. The second and third prototypes were delivered in 1937, with a fourth being completed in early 1938. The last three prototypes differed from first by having increased span ailerons, enlarged fins and a redesigned dorsal turret installation.
Kawanishi H6K1 Model 1 – Following the completion of Service Trials, the first, third and fourth prototypes were re-engined with 1,000 hp (746 kW) Mitsubishi Kinsei (Golden Star) 43 radial engines and entered service in January 1938 under the designation Navy Type 97 Flying Boat Model 1.
Kawanishi H6K2 Model 2 – First production model being generally similar to the re-engined prototypes except for minor equipment changes. Armament comprised three 7.7 mm (0.303 in) machine-guns on trainable mounts in bow, power-operated dorsal turret and non-powered tail turret, and up to 2,205 lbs (1000 kg) of bombs could be carried. In April 1940 this version was redesignated Model 11. Ten aircraft were built but the seventh and eighth aircraft were modified as experimental transports.
Kawanishi H6K3 – Two more aircraft virtually identical to the H6K2 were completed for use as VIP Transports and designated H6K3.
Kawanishi H6K4 Model 22 (Model 2-2 & 2-3) – The major production version was the H6K4 which had the fuel capacity increased from 1,708 Imp. gallons (7765 litres) to 1,950 Imp. gallons (8864 litres) and improved defensive armament comprising of two beam blisters, each holding a single 7.7 mm (0.303 in) machine-gun (this replaced the dorsal turret), two open bow positions, each holding a single 7.7 mm (0.303 in) machine-gun and an open dorsal position with a 7.7 mm (0.303 in) machine-gun plus one 20 mm Type 99 Model 1 cannon in a tail turret. Its powerplant was unchanged initially, but from August 1941 the Kinsei 43 engines (Model 2-2) were replaced by the 930 hp (694 kW) Kinsei 46 (Model 2-3). A total of 127 aircraft were completed (with both engines) and were jointly redesignated Model 22.
Kawanishi H6K2-L – Following successful testing of the H6K3, the company began production of the H6K2-L, based on the early H6K4 with Kinsei 43 engines, and equipped to accommodate 18 passengers. Sixteen of this version, were completed and delivered to the Kaiyo (Ocean) Division of Dai Nippon Koku K.K. (Greater Japan Air Lines) which assigned the type to the Yokohama-Saipan-Palau-Timor, Saigon-Bangkok and Saipan-Truk-Ponape-Jaluit routes. Modifications included the removal of all armament, and the interior fuselage arrangement was revised to provide for the installation of a mail and cargo compartment in the hull forward of the cockpit, galleys behind the cockpit, a midship cabin with seats for eight or sleeping accommodations for four followed by an aft cabin with 10 seats and aft of this were toilets and another cargo compartment.
Kawanishi H6K4-L – Unarmed transports based on the H6K4 using Kinsei 46 engines and supplied with additional cabin windows. Production totaled 20 aircraft but a further two H6K4 aircraft were converted to the transport standard. For some unknown reason the tail turret was retained, but without armament. 20 aircraft used by the Japanese Navy with the two converted aircraft being supplied to Dai Nippon Koku K.K. (Greater Japan Air Lines).
Kawanishi H6K5 Model 23 – Generally similar to the H6K4, deleted the open bow gun position and introduced a turret with a single 7.7 mm (0.303 in) machine-gun immediately to the rear of the flight deck, and performance was improved by the installation of uprated Kinsei 51 or 53 engines. 36 aircraft.
The seven tonne Z-10, built by CAIC, entered service with the Chinese Army in 2012. While some French and Israeli hard- ware is reportedly used on the Z-10, all mission software is reportedly indigenous. The digital cockpit features HUD, multi- function displays, night-vision goggle compatibility, fully-integrated navigation systems and a fly-by-wire control system. Later aircraft are equipped with terrain- avoidance and terrain following radar.
The primary mission for the treetop hugging WZ-10 is battlefield interdiction, eliminating the enemy ground fixed and mobile forces, and concurrently certain air combat ability. Development of a dedicated attack helicopter began in the mid-1990s at the 602 Institute and Changhe Aircraft Industry Company (CHAIC) in Jingdezhen, Jiangxi Province.
The design uses the power plant and transmission derived from the Harbin Z-9, with the fuselage modified to accommodate two pilots.
The helicopter can carry up to 8 ATGMs, or IR-guided short-range AAMs. Although the helicopter might still not be as capable as the U.S. AH-64 Apache, it will probably play a significant role in Army Aviation modernisation and force compabilities.
The navigation and avionics are probably from domestic sources. The navigation system consists of radioaltimeter, doppler radar and GPS.
Reports indicate that the WZ-10 has an optics system that relays sensor information to the pilots helmets; essentially a system similar to the US Integrated Helmet and Display Sighting System (IHADSS). The helmet system also controls the direction that the machine gun is aiming. This allows the pilots to have an improved situation awareness as they can monitor flight systems and observe the terrain.
Two wings along the fuselage that are roughly 4.32 meters long may carry 1,500 kilograms of munitions, including a 57.0 mm multibarrel rockets, the red arrow 10(HJ-10) anti-tank missile. A 23 mm machine gun is fixed to the cabin at the front of the helicopter.
The fire control system is similar to the French Starry Night digital integration design.
The WZ-10 is also equipped with radar warning systems and with systems that will alert the crew that it has been targetted with laser range finders. The helicopter is also equipped with passive countermeasures and in an effort to reduce fratricide is equipped with IFF.
The cabin’s bulletproof glass may resist 7.62 millimeter ammunition and composite armor under the cabin resists 12.7 millimeters machine gun fires. The cabin is equipped to maximize fire protection and thw WZ-10 is also outfitted with ejection seats similar to the Ka-50.
China’s Z-10 attack helicopter can carry the HJ-10 SAL-guided missile. Also known as the AKD-10, this has a range of up to 8 km. The HJ-10 (AKD-10) is China’s third-generation of battlefield anti-tank missile (after the HJ-8 and HJ-9), and the first to be developed as an airborne weapon from the outset. The HJ-10 forms part of the wider weapons and systems package that has been produced for the Changhe Z-10 (WZ-10) combat helicopter. The HJ-10 is in the same class as the US AGM-114 Hellfire but follows a slightly different design approach. The status of the HJ-10 is closely linked to that of the Z-10 attack helicopter which has been under secretive development in China since the late 1990s. The Z-10 is China’s first modern combat helicopter but it has received considerable technical assistance and direct design input from several Western suppliers. The main obstacle to progress for the programme has been to secure a suitable indigenous powerplant. A handful of Z-10 prototypes flew with Pratt & Whitney Canada PT6C turboshafts, but production standard aircraft (perhaps designated Z-10A) are to be powered by a Chinese-built WZ-9 engine. Delays in fully developing and producing these engines have slowed the Z-10’s entry into service with the People Liberation Army (PLA).
Prototype for basic tests. Not all has the same layout in that some had fenestron configuration while others had traditional tail rotor configuration； some had chin gun turret while other had chain gun; some had nose mounted electro-optical system while others had mast mounted electro-opical system. During test flights, test pilot had to make numerous dangerous emergency landings due to various malfunctions.
Pre-production series powered by Pratt & Whitney Canada PT6C-76 turboshaft engine.
Simplified Z-10H powered with domestic Chinese WZ-9 engine of 930 – 950 kW range. Due to the drastic reduction of power by nearly a third, MASWS, IRCM and some other subsystems removed； armor is also greatly reduced to save weight.
3 samples built for Pakistan with equipment missing in Z-10K added back, powered by WZ-9C engine with maximum power around 1000 – 1100 kW. Was not selected by Pakistan after evaluation, but the design was used to upgrade Z-10 built earlier when more powerful engine became available.
Upgraded variant first unveiled in 2018 with active and passive countermeasures, missile approach warning system, radar warning receiver, new engine exhaust nozzle pointed upwards to reduce infrared signature, new intake filtration systems and armor panels, more powerful 1200 kW engine, larger ammunition magazine, appliqué graphene-based armor panels, infrared jammer, and a new IFF interrogator.
Z-10 millimeter wave radar
Equipped with Z-19’s millimeter wave radar for ground testing.
Coastal Command had really earned its spurs during the Second World War; not only were its allocated squadrons involved hunting U-boats, they also carried out attacks on surface shipping and introduced a fully fledged search and rescue service to the great benefit of those it rescued. Having risen greatly throughout the war Coastal Command would be afflicted by a great contraction immediately afterwards. As many of the command’s aircraft were American Lend Lease, such as the Catalina, their operating units quickly disappeared. Also disappearing almost overnight were those units whose personnel were mainly drawn from the Commonwealth; they decamped home in many cases taking their aircraft with them. Changes were also wrought upon the strike squadrons as they disbanded very quickly.
These changes also set the course for the command’s future thus anti-submarine, search and rescue plus meteorological fights became the post-war duties of Coastal Command. The majority of service aircraft would also be scrapped as the majority were war weary. Beaufighters, Mosquitoes and Halifax patrol aircraft would be rounded up and reduced to produce. These aircraft were replaced by new build Avro Lancasters for use in the General Reconnaissance and air-sea rescue roles while the Short Sunderland was used in a similar role over longer ranges. Joining the Lancaster and Sunderland would be the Handley Page Hastings MR1, which equipped No. 202 Squadron based at Aldergrove while detachments were undertaken to North Front, Gibraltar. Originally the maritime reconnaissance tasks were assigned codenames, which were Epicure from St Eval, Nocturnal from Gibraltar and Bismuth from Aldergrove. When the eight Hastings came into service only the Bismuth task force remained and these were divided into tracks labelled A to O. Sorties were selected by the Chief Meteorological Officer and, on a normal day, only one track was selected and flown. Things changed during exercises and alerts when more missions were undertaken, some of them at night. The Bismuth sorties were being flown when weather satellites were no more than just a dream thus the Met flights were providing very important data not only to the military, but to the nascent and burgeoning airlines starting to cross the Atlantic en masse. The squadron continued to provide this service until August 1964 when it was disbanded.
While the Avro Lancaster GR3 was undertaking sterling work it had become obvious that it was becoming long in the tooth thus a more capable replacement was sought. Initially a version of the Avro Lincoln was mooted, however the potential lack of growth in what was basically a bomber design saw this idea sent back to the drawing board. To fill the gap between the Lancaster and its replacement an approach was made to the United States to provide Lockheed Neptunes under the Mutual Defence Aid Programme (MDAP). The version of Neptune supplied to the RAF was equivalent to the US Navy P2V-5 and came complete with nose and tail gun turrets although these were soon improved by the fitment of a clear Plexiglas nose while the tail turret was replaced by a Magnetic Anomaly Detector (MAD), sting tail. The first of fifty-two Neptunes were delivered to No. 217 Squadron based at St Eval in January 1952, although by April the squadron had moved to Kinloss. This first Neptune squadron was quickly joined by No. 210 Squadron based at Topcliffe in February 1953 while No. 203 Squadron, also at Topcliffe, received its complement by March 1953. No. 36 Squadron was the final unit to form, also at Topcliffe, was reforming in July 1953.
Although the Neptune squadrons were declared operational there were numerous technical problems experienced with the aircraft. Not only did the weapons systems fail to work correctly but some of the electronic systems were not fitted before delivery and the Americans were slow to deliver the missing boxes preferring to give priority to their own forces. By 1955 the Neptunes were fully modified and operational thus they were able to take part in a major exercise over the Bay of Biscay called Centre Board. While the majority of Neptunes concentrated on the maritime reconnaissance role four were utilized for a completely different role that would have far reaching consequences for the future. On 1 November 1952, four Lockheed Neptune MR Mk 1s formed the inventory of Vanguard Flight of Fighter Command based at RAF Kinloss. Their purpose was to research and develop tactics for use by Airborne Early Warning aircraft.
Although disbanded in June 1953 the four Neptune aircraft of Vanguard Flight were reformed as No. 1453 (Early Warning) Flight at RAF Topcliffe in Yorkshire. Despite their anonymous role the Neptunes of No. 1453 Flight appeared like normal aircraft to the public as they retained the full armament of the P2V-5 variant with nose, dorsal and tail turrets. Details of No. 1453 Flight’s operations are scant, leading to speculation that they may have been involved in highly classified reconnaissance missions over or near the Eastern Bloc countries in a similar manner to the US Navy’s Martin P4M Mercator ELectronic INTelligence (ELINT) aircraft, and the ‘Ghost’ North American RB-45 Tornados that flew with RAF crews and markings from RAF Sculthorpe, over eastern Europe to provide radar images of potential targets for RAF and Strategic Air Command (SAC) bombers.
By 1957 there were sufficient replacements available to allow the Neptunes to be returned to America. No. 36 Squadron would disband in February 1957, although No. 203 had gone by August 1956. Other 1957 disbandments included No. 210 Squadron in January while No. 217 Squadron relinquished its aircraft two months later. No. 1453 Flight would end its mission in June 1956 with its machines returning home first.
Not only were the aircraft of Coastal Command changing so were its areas of responsibility. When NATO became operational in April 1951 the AOC-in-C Coast Command also became Allied Air Commander-in-Chief, Eastern Atlantic. This change resulted in HQ Command issuing its projected mid-1953 deployment and equipment. The planned eight Shackleton squadrons covering long-range patrol and maritime reconnaissance were deployed thus: four were allocated to South Western Approaches, three to North West Approaches and a single unit to Gibraltar. All eight units had an aircraft inventory of eight aircraft each. The Short Sunderland was still in service at this time and its deployment included two squadrons each deployed to the southern and northern approaches. As all four units were due to be disbanded or re-equipped their inventory stood at five aircraft each. The Neptune squadrons were concentrated to the east; one was allocated to the north-eastern approaches while the remainder covered the Eastern approaches. In common with the Shackleton units each Neptune squadron was equipped with eight aircraft. Meteorological duties were covered by five Hastings aircraft based at Aldergrove and their duties were set by the Chief Meteorological Officer. By this time the command was operating helicopters for short-range rescue and communications duties, as the operating squadron was divided into flights the sixteen helicopters were dispersed around the country.
Coastal Command also had an extensive support network; most of it was active during peacetime although some organizations were wartime only. Providing training for the front-line squadrons was the School of Maritime Reconnaissance (SoMR) and the Anti-Submarine Warfare Development Unit, both of which moved into St Mawgan when it reopened in January 1951. Should war break out No. 16 Group would be reformed at Chatham to manage the three Neptune units charged with patrolling the eastern approaches while No. 17 Group would reform at Benson for training purposes with No. 19 Group moving to Liverpool to cover the port facilities. The duties of the SoMR included giving sprog maritime aircrew their initial training during a three-month period when 100 hours of training were flown, leaving the Operational Conversion Units to concentrate upon the individual aircraft.
It would be the arrival of the Shackleton that would bring a great leap in capability to Coastal Command. The progenitor of the Shackleton was designed by Roy Chadwick as the Avro Type 696. It was based on the Lincoln bomber and Tudor airliner, both derivatives of the successful wartime Lancaster heavy bomber, one of Chadwick’s earlier designs, which was the current MR aircraft. The design utilized the Lincoln centre wing section and tail unit assemblies bolted to which were the Tudor outer wings and landing gear. These in turn were married to a new wider and deeper fuselage while power was provided by four Rolls-Royce Merlin engines. It was initially referred to during development as the Lincoln ASR3. The design was accepted by the Air Ministry as Specification R.5/46. The tail unit for the Shackleton differed from that of the Lincoln while the Merlin engines were replaced by the more powerful Rolls-Royce Griffons driving contra-rotating propellers. The Griffons were necessary due to the increased weight and drag and having a lower engine speed; they provided greater fuel efficiency for the long periods in the denser air at low altitudes that the Shackleton was intended for when hunting submarines better known as loitering.
The first test flight of the prototype Shackleton GR1, VW135, was undertaken on 9 March 1949 at the hands of Avro’s Chief Test Pilot J.H. Jimmy Orrell. In the antisubmarine warfare role, the Shackleton carried sonobuoys, electronic warfare support measures, an Autolycus diesel fume detection system and for a short time an unreliable magnetic anomaly detector (MAD) system. Available weaponry included nine bombs, three torpedoes or depth charges, while defensive armament included two 20mm cannon in a Bristol dorsal turret. The aircraft was originally designated GR1, although it was later redesignated the MR1. The Shackleton MR2 was an improved design incorporating feedback from the crews’ operational experience. The radome was moved from the earlier position in the nose to a ventral position, which improved radar coverage and minimized the risk of bird-strikes. Both the nose and tail sections were lengthened while the tailplanes were redesigned and the undercarriage was strengthened.
The Avro Type 716 Shackleton MR3 was a radical redesign of the aircraft in response to crew complaints. A new tricycle undercarriage was introduced while the fuselage was lengthened. Redesigned wings with better ailerons and tip tanks were introduced, although the span was slightly reduced. To improve the crews’ working conditions on fifteen-hour flights, the sound proofing was improved and a proper galley and sleeping space were included. Due to these upgrades the take-off weight of the RAF’s MR3s had risen by over 30,000lb and assistance from Armstrong Siddeley Viper Mk 203 turbojets was needed on take-off, although these extra engines were not added until the aircraft went through the Phase 3 upgrade. This extra weight and increased fatigue consumption took a toll on the airframe thus the service life of the RAF MR3s was sufficiently reduced that they were outlived by the MR2s. In an attempt to take the design further the Avro Type 719 Shackleton IV was proposed. Later redesignated as the MR4 this was a projected variant using the extremely fuel efficient Napier Nomad compound engine. Unfortunately for Avro the Shackleton IV was cancelled in 1955 as the RAF was shrinking as financial cuts and a contraction of responsibilities was taking place.
The Shackleton MR1 entered service with the Coastal Command Operational Conversion Unit at Kinloss in February 1951. Even as the first Shackletons were entering service with the newly created No. 236 OCU the Royal Navy was trying to scupper the whole of Coastal Command. Their plan was to scrap Avro’s finest and replace them with a fleet of Fairey Gannets operating off small aircraft carriers in midocean while further aircraft would cover the inshore areas. Once the idea had been fully costed it was obvious that the whole plan was fundamentally flawed. Within the command itself the flying boat lobby was also reacting vociferously putting forward the type as a more flexible design, however this too was shot down in flames when it was pointed out that rough sea conditions would either stop them flying or actually wreck the aircraft. Also, flying boats were inherently slow and heavy and the proliferation of runways of sufficient length were springing up all over the world and many of these countries were still susceptible to British entreaties.
No. 224 Squadron based at Aldergrove would be the first unit to receive the Shackleton MR1 in July 1951 replacing the unit’s weary Handley Page Halifax GR6s. Other units that received the Shackleton MR1 included No. 220 Squadron, which initially formed at Kinloss in September 1951 although the unit moved to St Eval in November. In May 1952 No. 269 Squadron based in Gibraltar received its allocation of MR1s while its crews were formed from the nucleus of No. 224 Squadron. By March, however, the entire squadron had returned to Britain taking up residence at Ballykelly. No. 120 Squadron had already been equipped with the Shackleton MR1 in March 1951 while based at Kinloss, although this tenure was short as the entire unit decamped to Aldergrove in April 1952. While at Aldergrove No. 120 Squadron provided the nucleus for No. 240 Squadron, which was also based there. The squadron quickly moved to its new base at St Eval for a few weeks before settling at Ballykelly. No. 240 Squadron would later be renumbered as No. 203 Squadron in November 1958, although this unit would be equipped with the MR1A version that featured slightly more powerful engines amongst other improvements. The Shackleton MR1A was also used by No. 42 Squadron based at St Eval retaining this model until July 1954. No. 206 Squadron was also based at St Eval when it re-equipped with the MR1A in September 1952; the squadron retained this model until May 1958. The last unit to equip with the MR1A was No. 204 Squadron, which traded in its more advanced Shackleton MR2s for the less capable MR1As in May 1958 while stationed at Ballykelly. The MR1As remained in use until February 1960, although by this time the squadron had received some MR2Cs that it retained until March 1971.
The arrival of the Shackleton MR2 would improve the capabilities of the MR squadrons and, in most cases, this new marque would replace the MR1/1A in use. Deliveries to operational units began in 1953 with first deliveries being made to No. 42 Squadron. Initially the squadron retained some of its complement of MR1As until July 1954 as the entry of the MR2 into service was slow, although once the technical problems had been ironed out the type served until 1966. No. 206 Squadron would receive some MR2s in February 1953, although they were dispensed with in June 1954, the unit retaining its complement of MR1As throughout this period. In January 1958 No. 206 Squadron departed St Eval for St Mawgan, remaining there until July 1965 when a further transfer was made to Kinloss. In March 1953 two units would start to accept deliveries of Shackleton MR2s. The first would be No. 240 Squadron based at Ballykelly, although their tenure was short as they were dispensed with in August 1954, the unit resuming operations with MR1s. By November 1958 No. 204 Squadron had been renumbered as No. 203 Squadron still at Ballykelly. No. 203 Squadron would later receive MR2s in April 1962, retaining them until December 1966. The other unit that gained MR2s would be No. 269 Squadron, also based at Ballykelly. The initial allocation lasted until August 1954, the squadron resuming operations flying its original MR1s, which remained the case until October 1958 when a new batch of Shackleton MR2s was received. By December No. 269 Squadron had been renumbered as No. 210 Squadron as part of the contraction of the RAF and the desire of Coastal Command to retain significant unit number plates. No. 210 Squadron would remain as part of Coastal Command and into the early days of Strike Command before disbanding on 31 October 1970 only to reappear the following day as a Near East Air Force squadron.
No. 120 Squadron was based at Aldergrove and had a bit of a hit and miss affair with the Shackleton MR2. The first deliveries were made in April 1953, although all had been returned by August 1954, the unit resuming operations with its MR1s. The squadron received another allocation of MR2s in October 1956 and retained these until November 1958. No. 224 Squadron had slightly better luck with its MR2 allocation that was taken on charge in May 1953, retaining them until disbandment in October 1966.
Ballykelly would also be home to No. 204 Squadron, which had last been in existence as a Vickers Valetta unit before renumbering as No. 84 Squadron in February 1953. The squadron would receive its complement of MR2s in January 1954, which remained in use until May 1958 when they were replaced by Shackleton MR1As. These remained in service until February 1960 by which time the first of the replacement MR2s had arrived. No. 204 Squadron retained its MR2Cs until disbandment in March 1971. The MR2C model differed from the basic MR2 in that it was fitted with the avionics suite from the later MR3. Instead of a base transfer No. 204 Squadron would be disbanded on 1 April 1971 reforming on the same date at Honington. The squadron would supply detachments to Majunga, Tengah and Masirah – the unit had originally been known as the Majunga Detachment Support Unit. The purpose of the Majunga, Madagascar, detachment was to provide aircraft for the blockade of Rhodesia. When the Rhodesian blockade was withdrawn in 1972 No. 204 Squadron was disbanded, its Tengah and Masirah patrols being covered by other units on rotation.
The Shackleton MR2 underwent extensive trials of its avionics and remedial work on its engines, which had a tendency to throw spark plugs from their cylinder heads and required an overhaul every 400 hours. Trials were carried out with the MR2 at the Anti Submarine Warfare Development Unit (ASWDU) covering the performance of the ASV Mk 13 and extensive trials of the RCM/ECM suite before they were cleared for use. The Autolycos diesel fume detection system was also put through its paces before being cleared for service use. Other trials undertaken by the MR2 included the Glow Worm illuminating rocket system, the Shackleton replacing the last Lancaster in operational use. At least one MR2 was utilized for MAD sting trials, although both it and the rocket were dropped. However, the former would equip the later MR3 once all the bugs had been ironed out. Fortunately, the Orange Harvest ECM system, homing torpedoes and the various sonic buoys at least were successful.
The genesis of the Shackleton MR3 would rest upon the need for Coastal Command to cover its projected strength of 180 front-line aircraft by 1956. Although other projects had been put forward the Air Staff finally plumped for the Avro product, issuing OR.320 in January 1953. The first Shackleton MR3 made its maiden flight on 2 September 1955, although production aircraft did not reach service until 1957 by which time some of the contracts had been cancelled. The MR3 was a complete contrast to the earlier models in that it was carried on a tricycle undercarriage, had wing-tip mounted fuel tanks, modified ailerons, a clear view canopy and a sound proofed wardroom to help alleviate the effects of long patrols. Defensive armament consisted of a pair of nose-mounted 20mm cannon, the upper turret being deleted. During 1966 a programme was instituted to upgrade the MR3, the most obvious change being the fitment of a Bristol-Siddeley Viper engine in each outboard engine nacelle resulting in the type being designated the MR3/3.
First deliveries were made to No. 220 Squadron based at St Mawgan in August 1957, although the unit retained some of its MR2s. The squadron had a short existence as it was renumbered as No. 201 Squadron in October 1958. This unit would last a lot longer than its predecessor as it remained as a Shackleton operator until 1970 having moved to Kinloss in December 1965. Close on the heels of No. 220 Squadron to equip with the Shackleton MR3 was No. 206 Squadron, also based at St Mawgan. This unit traded in its 5/3 mix of MR1As and MR2s for a similar number of the new model in January 1958. No. 206 Squadron would also move to Kinloss, departing St Mawgan in July 1965 and remaining there until re-equipping in August 1970.
St Mawgan was also the home for No. 42 Squadron, although this unit would continue to fly some of its MR2s alongside the MR3s after their delivery in November 1965, retaining them until replacement in September 1971. Ballykelly and No. 203 Squadron would be the final recipient of the Shackleton MR3 in June 1966 having first used this model between December 1958 and July 1962. No. 202 Squadron would leave Coastal Command in February 1969 when it was transferred to Luqa, Malta, as part of Near East Air Force (NEAF).
Development of weaponry for the Shackletons continued apace with the Mk 30 Homing Torpedo finally being cleared for service in March 1955 after a period spent trying to get the delicate mechanisms to work properly under operational conditions. With this weapon in service it would see the final demise of the depth charge as the primary anti-submarine weapon. To complement the Mk 30 development work was also taking place on an active homing torpedo codenamed Petane. Unfortunately, delays in clearing the torpedo for service use would result in cancellation and its replacement by the American Mk 43 weapon although the latter’s strike rate was less than that of the British weapon. Also missing from the Shackleton fleet was an airborne lifeboat that had been prominent under the Lancaster GR3s. Although a boat was planned for the Shackleton it was never developed and the fleet was supplied with Lindholme gear that became a standard throughout the command. Avionics for the Shackleton were also under continual improvement, Orange Harvest was constantly being improved while a Doppler system known as Blue Silk was also developed, which was an improvement on the Green Satin system. The primary radar system installed in the Shackleton was the AN/ASV-21 developed for submarine detection; this too was in a state of constant development in order to improve its capability and its ease of operation.