The Russian airplane designer, Igor Sikorsky, is well known for creating the four-engine Il’ya Muromets bomber-reconnaissance air craft in 1914, an achievement that marked the beginning of a new era in Russian aviation. He is less well known, however, as the designer of fighters. This article is dedicated to the history, construction, and use of Sikorsky fighters during World War I.
In late 1914, the aeronautical division of the Russian-Baltic Wagon Works (Russko-Baltysky Vagonny Zavod (RBVZ) or Avia-Balt)  completed construction of the first seven four-engine Il’ya Muromets B series. A delay in the turnout of the next series of airplanes allowed Sikorsky to use the time available to produce a new lightweight airplane–the S–16. Sikorsky relied on the experience gained during his design of the S–8 Maljutka in 1912. The S–8 was a two-seat training biplane powered by a 50-hp French Gnome rotary engine; the pilot’s and student’s seats were placed side-by side and the airplane had dual controls. Indeed, the S-8 may be considered the prototype for the S-16, lending the latter some structural ideas and details. Sikorsky also acknowledged the influence of Sopwith’s Tabloid. On the whole, the design work sought to reduce the S-16 airplane’s size and simplify its structure.
Completed in October, the S-16 was a single bay biplane, powered by an 80-hp Gnome rotary engine. On the two-seat version, the pilot’s and observer’s seats were located side-by-side. Its large wing area (25.36 square meters) and bulky Farman-type undercarriage were better suited for reconnaissance types than for fighters. However, the result was a plane that would perform both reconnaissance and fighter operations.
The S–16 also could be modified easily and thus appeared in various forms. One S-16, works number (No.) 156 for example, was equipped with a seven-cylinder Kalep engine and an upper wing area that was two meters larger than the lower wing. While the lower wings lacked ailerons, the upper wings contained greatly-enlarged ailerons. Sikorsky intended the S–16 as a training and high-speed reconnaissance airplane for the Airships Squadron (Eskadra Vozdushnykh Korabley, or EVK)–the unit formed by Il’ya Muromets. In December, the S–16s were detached from the army into a separate unit and subordinated to the Supreme Commander-in-Chief of Staff. Later, the S-16s were used to guard the airships’ home air fields and as an escort fighter.
Meanwhile, in November, Avia-Balt had begun constructing three S–16 airplanes (Nos. 154, 155, and 156). The first of these, powered by a Le Rhone 80-hp engine, was completed in January 1915. It was sent to Revel and delivered to Imperial Navy pilot Lt. Georgy Lavrov. But, deep snow prevented testing the airplane’s wheels and undercarriage. In March, Lavrov and his S-16 were transferred to the Airships Squadron. On March 6, the other two S-16s were sent to the squadron’s detachments in Jablonna and Warsaw. All three planes were tested under combat conditions and successfully passed their tests. During the summer, the Airships Squadron pilots continued to test the S 16 with the following results: speed-144 km/hr, and time to climb to 1,000 meters with full load (225 kg)-4 minutes. The tests persuaded the Central Military Technical Department to contract with Avia-Balt for the construction of fifteen S-16s (Nos. 201-215).
The Il’ya Muromets was the major product line of Avia-Balt and even a small production run of another airplane series posed concern. The main problem–affecting all of Russian aviation– involved severe shortages of engines and machine guns. German aircraft, on the other hand, were fully armed with synchronized and turret, ring-mounted machine guns. One indication of the acuteness of the situation was evident in a March 17 telegram from a Russian airplane inspector at the front: “there are no machine guns for small apparatus [S-16], only two airplanes have armament–one from the XIIth Army, another from the XIth.” As a result, the majority of S-16s were sent to the Airships Squadron without them. Engines and armament were fitted at the squadron’s workshops when they became available. Initially, the cost of production and ensuing difficulties posed seemed not to outweigh the evident advantages of the new airplane. Soon after the tests, Airships Squadron commander, General-Major M. V. Shidlovsky reported: “S-16 apparatus are the most high speed…equipped with the device for shooting through the propeller from [a] Vickers machine gun. [The] Sikorsky sixteenth, with [a] machine gun could be a serious threat to the enemy airplanes.” At the beginning of 1916, the Airships Squadron received the first six fighters produced, while delivery of the remaining twelve was delayed. All of the airplane ordered were accepted, but their dispatch to front was postpone because of the lack of synchronized machine guns. When the first S-16 airplane arrived without armament, the Central Military Technical Department decided to equip the S-16 with Vickers or Colt machine guns. Airships Squadron Navy pilot Lt. Lavrov himself developed the synchronizer. In addition, some of the two-seat S-16s were equipped with a machine gun for rearward shooting.
Grand Duke Alexander Mikhailovich, the airplane and aeronautics commander of the Army in the Field, took an interest in the new S-116 lightweight fighter. At that time Airships Squadron heavy airplane were withdrawn from the Grand Duke’s command and placed under the direct command of the Supreme Commander-in-Chief of Staff (Verkhovnoe Glavnoe Komandovanie-VGK). On February 3, the Grand Duke sent a telegram to Gen. M. V. Alekseev, the head of the VGK staff, demanding: “[why hasn't] the [S-16] squadron yet [been] sent to the VIIth and XIth Army…. [these planes] are the most high speed nowadays. Otherwise reconnaissance in the future would be impossible.” Alekseev replied: “of twelve machines [on hand, we are] ready to let [activate] six.” Soon, the first fighter air detachments, including the combat airplane necessary to equip them, were formed in Russia. Fighters were in small supply. Also, since the French-built Nieuport XI and Spad A.2s were delivered in limited numbers, the S-16′s appearance seemed timely.
In February, Avia-Balt received the following telegram: “by [his] Imperial Majesty’s order, prepare for the urgent departure to Zhmerinka for the 6th Air Company, three ready S-XVIs with machine gun installations for Gnome [engines and] Vickers [machine guns]. The aforesaid departure should be done no later than [the] 27th of February.” The airplanes (Nos. 201, 202, and 204) were accepted by 2d Lt. Ivan Orlov, recently appointed to command the new 7th Fighter Air Detachment, an element of the 6th Air Company, near Kiev. On March 19, three more S-16s, equipped with Gnome 80-hp engines and machine guns, were sent to Kiev for the 7th Fighter Air Detachment. The airplanes were enthusiastically accepted by the unit’s pilots. Test flights began in April, with Pilot Ensigns Gilsher and Matveevich flying aboard No. 201 and 2d Lt. Bychkov aboard No. 202. In all, they completed ten 25-minute-long flights over Jablonna airfield and soon became proficient with the new airplane and its capabilities. Lt. Orlov, flying No. 204, initiated combat patrols on April 15, but did not encounter any enemy air planes. The S-16′s first combat took place on April 8. On that day Lieutenant Bychkov–with Observer Ensign Kvasnikov aboard–took off, following signals from a ground observation station to intercept a hostile airplane in the region of Dobropole. Visibility was poor because of fog and a layer of clouds. Soon the pilots discovered the enemy, who began to fire. After several shots the enemy disappeared into the clouds and then descended towards their position. On April 20, a three-ship section of the 7th Fighter Air Detachment took off to intercept an enemy airplane. After being attacked, Orlov, Gilsher, and Bychkov drove the enemy back behind the front lines. During the days that followed, the 7th’s pilots engaged in air combat with enemy airplanes and each time forced them to retire behind the enemy’s lines.
During these operations, Russian pilots discovered some deficiencies in the synchronizing mechanism of the machine guns. Frequently during a crucial period of battle, the mechanism went “out of sync.” In April such cases were outlined in the reports of Ensign Gilsher, aboard No. 201 and Lieutenant Orlov, aboard No. 201 and 204. Also, there were several cases of engine stoppages in the air, with some forced landings. On April 27, Lieutenant Bychkov, aboard No. 202, made a forced landing; his airplane was damaged and sent for repair.
That day four sorties took off in pursuit of hostile airplanes. On one mission, Ensign Gilsher attacked an airplane over Burkanov at an altitude of 2,500 meters. After expending 120 rounds, Gilsher shot down his opponent, who was last seen covered with dense smoke as the enemy plane dove to the ground. With Observer Ensign Kvasnikov aboard, Gilsher then took off again. Unable to locate the enemy, the Russians headed home; but while landing, their aileron control system jammed. The elevators were also jammed in the down position, locked by loss of rudder control. Thanks to the efforts of the pilot and observer, they managed to free the right elevator. Unfortunately, the left elevator remained jammed, causing the airplane to go into a spin and crash. Badly wounded, Gilsher and Kvasnikov were rushed to a hospital, where Gilsher’s left foot was amputated. However, owing to his dogged persistence, Gilsher later managed not only to return to his detachment, but to fly again. Fitted with an artificial limb, Gilsher went on to win several more air battles.
When the Grand Duke Alexander Mikhailovich learned of the crash, he immediately suspended S–16 flights and ordered all of the aircraft returned to the Airships Squadron. At the same time that these mechanical problems arose, the pilots reported other deficiencies in the S–16s. Pilots of the 7th Fighter Air Detachment complained that the S–16 was much slower at level speed than the German Albatros, especially the latest types. The S–16′s rate of climb was also considered unsatisfactory. It took fifteen minutes to climb 1,000 meters, fifty minutes to climb 2,000 meters, and a very slow hour and fifteen minutes to reach 2,500 meters. While airplane stability was acceptable, the S–16 was “sharply disturbed” in steep turns. Pilots from the 7th Fighter Air Detachment noted that some of the airplanes were poorly assembled, causing the failure of vital parts. During the S–16′s period of service, it experienced five synchronizer failures in the air. Delicately attached control levers and structural defects throughout the control system were also noted. Poor pilot visibility posed another serious disadvantage, making “the discovery of the enemy in the air almost [a] pure accident.” In addition, the gun installation was unsatisfactory and aiming made impossible because of heavy engine vibration.
An investigative commission of the 7th Fighter Air Detachment concluded that “S-16 airplanes are appropriate neither for service as fighters nor for the flights in general…it is undoubtedly dangerous to fly that airplane.” During their service with the 7th, between April 15 and May 5, 1916, the three S-16s made twenty-seven flights. Twenty-two were combat flights, lasting a total of 30 hours, 47 minutes. During that period, one hostile airplane was shot down. After the crash on April 27th, S-16 No. 201 was taken out of service.
The reports were similar from other fronts. At the end of March 1916, S-16 No. 205, with the Le Rhone 80 hp engine and a synchronized machine gun, was delivered from the 7th Air Company to the 33d Corps Air Detachment (Northern front) for Military Pilot 2d Lt. Konstantin Vakulovsky. On March 27, Vakulovsky took off from the airfield in Kreitsburg to pursue a twin-engine German airplane. Vakulovsky attacked the enemy at an altitude of 3,400 meters in the region of Stockman-shof, but the German pilot flew off. On April 2, Vakulovsky flew a reconnaissance mission and was fired on by his own artillery. A projectile burst underneath his airplane stopped the engine. Shell-shocked, the pilot lost consciousness for a short time. When he came to, he began to glide and landed on a bog near Vikemujzhe. During the landing, the propeller was damaged and a wing strut crumpled. On April 28, the airplane was returned to the 7th’s air park and its engines handed over to the 20th Corps Air Detachment. Thus, only two combat flights lasting two hours and fifteen minutes were made on S-16 No. 205.
Beginning April 5, 1916, two S-16s (Nos. 203 and 211), each equipped with a Gnome 80-hp engine, were used in the 12th Fighter Air Detachment of the Northern front. Military Pilot 2d Lt. Max Lerkhe, the detachment commander, flew the planes.
After training flights on April 23, Lieutenant Lerkhe, with Observer Senior Noncommissioned Officer Kanavin aboard, made the first combat flight, but did not encounter any hostile airplanes. Similar flights were made on May 21 and 22. On June 21, Lerkhe pursued a German airplane above Kurtenhof. As Lerkhe approached the enemy, having overtaken him at a height of 210 meters, the German pilot immediately flew off, crossing the trenches near Bersemunde. On his way back to the airfield, Lerkhe noticed an Albatros in the region near Dalen Lake taking heavy fire from Russian batteries. Lerkhe attacked the Albatros from behind and was about to open machine gun fire, when the Albatros turned and Lerkhe noticed it bore Russian roundels. He quickly stopped his attack and returned to his airfield. 
The last S-16 was used in the 12th Fighter Air Detachment on June 26. On that day Lerkhe flew towards artillery bursts and found a hostile airplane directing fire towards the Russian trenches. He overtook the enemy near Baldon and attacked it, unloading his entire cartridge belt, with no effect. In his report, Lerkhe remarked that the S-16 “was not fit to serve as a fighter.” On the whole, from April to June 1916, the 12th Fighter Air Detachment made five flights aboard S-16s. That summer the two airplanes (Nos. 203 and 211) were returned to the Airships Squadron at Zegevold. Six other S-16s (Nos. 154-156, 207-209) remained in service in the Airships Squadron. Three were with the 2d Combat Detachment(Zegevold) at the Northern front, two others with the 1st Combat Detachment (Kolodzia, Ternopol region) at the Southwest front, and one used for training at the Air Detachment Flying School in Pskov.
In the summer of 1916, when it became clear that the S-16′s speed of 120 km/hr was insufficient for a fighter, a Gnome-Monosoupape 100-hp engine was installed on No. 210. The conversion raised the plane’s speed to 154 km/hr. The next series of S-16 aircraft were prepared for that type of engine. The first of this S-16-3 series (No. 246) was delivered for testing to the Airships Squadron in August 1916. The new series was distinguished by a more streamlined form and the presence of an upper fuselage faring. The upper wing span was greater than the lower one, and the latter had no ailerons, while those of the upper wing were enlarged. The biplane was transformed into a sesquiplane, in compliance with the general development of fighters.  The first of the new series–built in January 1917–was followed by fourteen more (Nos. 247 260), but none reached the front as they lacked engines. The Grand Duke refused to grant engines for the new series of S-16 fighters, so the last fourteen S-16-3 were stored in the assembly shop of Avia-Balt until May 1919.
After the October 1917 revolution, the Bolsheviks demobilized the Imperial Russian army, including the Airships Squadron, whose remnants were driven from the front deep into Russia. On December 23, 1918, the fourteen S-16-3 airplanes were stored at Avia-Balt were assembled and transferred to the Central Aircraft Depot in Moscow, where they were gradually equipped with engines and then sent to the Red Army. The new Red Army airplane formation was created as the Division of Airships (Division Vozdushnykh Korabley–DVK). In July 1919, S-16-3 No. 247 was given to the Moscow Flying School but did not serve there long. Pilots in that school trained in specified types of aircraft that were in Red Army service; the S-16 was not among them.
In June 1919, S-16-3 No. 248 was delivered to the 38th Air Detachment, an element of the Byelorussian-Lithuanian Air Service, based near Orsha. Several flights were made there, but the airplane crashed during a forced landing in July. The White Army also used several of the airplanes during the Russian Civil War. Captain V. Lobov, a pilot from the 1st Kuban Cossack Air Detachment, flew one of them. Another S-16 was used by White Army pilots at the Sevastopol Flying School in the Crimea.
Two S-16-3s (Nos. 250 and 252) were sent from Moscow to Lipetsk, at the Division of Airships base. Airplanes Nos. 249, 251, 253-255, and 257 were not mentioned at all in the Division of Airships documents and most probably remained at the Central Aircraft Depot in Moscow. By January 1920, No. 250 had flown a total of one hour and thirty minutes. Damaged during a land ing in February, the airplane was under repair until another engine was installed (a Le Rhone 80hp). In May, the next crash completely wrote it off. Similarly, No. 258 arrived at the Division of Airships on May 17, 1920. After assembling and mounting a Le Rhone 80-hp, it was sent by train to the front, where it was used during the summer of 1920 by the 1st Combat Detachment near Mogilev.
S–16-3 No. 252, with Le Rhone 80-hp, was sent to the Division of Airships base on June 25, and remained there until September 15, when it made its first test flight. The airplane was damaged by pilot Berezhkov. Although sent for repair, it was later written off. In December 1920 Nos. 256 and 259 arrived without engines at Sarapul from the Moscow Air Depot. But, before the planes could be assembled and tested, they were destroyed during a fire.
S–16-3 No. 260 had arrived at the Division of Airships in the spring of 1920, and was fitted with a Le Rhone 80-hp engine. The assembly of that air plane lasted for several months and test flights began in the autumn. In November 1920, the air plane crashed, having spent a total of two hours and twenty minutes in the air. Numbers 164 and 165 were also mentioned in the Division of Airships’ documents, but in fact they were one and the same. Accepted in January 1920, the airplane was used for training flights until March, when it was damaged. After repair, the airplane was transferred to a training unit, where it was damaged, then returned to the Division of Airships and after the next crash written off. At the beginning of 1922–when the Division of Airships disbanded–all S-16-3s that were kept at the Central Aircraft Depot were written off, effectively ending the eight-year history of the S–16.
(1.) The factory was located in Latvia, while the Avia Balt was a branch set up in Petrograd to manufacture aircraft.
(2.) Because of Russia’s limited manufacturing capability at this time, the Russians often put captured enemy aircraft into service.
(3.) The sesquiplane form, with its large top wing and small lower wing had been popularized by Nieuport in France and widely copied.
The S-16 was the first Sikorsky fighter with a machine gun synchronized to fire through the propeller without hitting the blades and was the first Russian fighter actually built in Russia. The 4-wheeled front landing gear was intended to deal with “soggy Russian fields” and the airplane could be equipped instead with a pair of skis for when those soggy fields became frozen during the harsh Russian winters
During the First World War most Russian squadrons flew French-designed aircraft, many of them built under licence. Sikorsky’s single-seat S-13 and S-14 biplanes were probably not completed; the S-15 was a seaplane of the S-10 family. Three two-seat S-16s were built as trainers for bomber crews of the Squadron of Flying Ships in 1915, followed by about twenty-four more as two-seat S-16-2 and single-seat S-16-3 bomber escort and reconnaissance scouts with 80hp Gnome engines in 1916-17. A machine-gun was mounted under the top wing, firing clear of the propeller, until Engineer Lavrov invented an interrupter gear for a fuselage-mounted gun.
For winter operation, a number of S-16s were flown on skis in place of the standard four-wheel landing gear; at least one was fitted with twin floats in 1916. Contemporary accounts show that pilots enjoyed the stability, maneuverability and delicate controls of the S-16s, but they were outclassed by German fighters of the time.