SOAR MH-47E Chinook Helicopter.
The MH-47G Special Operations Aviation (SOA) version is currently being delivered to the U.S. Army. It is similar to the MH-47E, but features more sophisticated avionics including a digital Common Avionics Architecture System (CAAS). The CAAS is a common glass cockpit used by different helicopters such as MH-60K/Ls, CH-53E/Ks, and ARH-70As. The MH-47G also incorporates all of the new sections of the CH-47F.
The new modernization program improves MH-47D and MH-47E Special Operations Chinook helicopters to the MH-47G design specs. A total of 25 MH-47E and 11 MH-47D aircraft were upgraded by the end of 2003. In 2002 the army announced plans to expand the Special Operations Aviation Regiment. The expansion would add 12 additional MH-47G helicopters. On 10 February 2011, leaders and employees from the H-47 program gathered for a ceremony at Boeing’s helicopter facility in Ridley Park, PA, to commemorate the delivery of the final MH-47G Chinook to U.S. Army Special Operations Command. Modernization of MH-47D/E Chinooks to MH-47G standard is due for completion in 2015
On September 21, 1961, the Boeing-Vertol Model 114 lifted off on its maiden flight. The company produced the helicopter as a result of a September 1958 U. S. Army requirement for a medium transport helicopter capable of lifting a 4,500-pound load in all weather. In March 1959 the Army adjudged the modified Boeing- Vertol Model 107 winner of the competition. The Army placed an initial order for five units and classified the helicopter as the CH-47 Chinook. The machine’s fuselage served as a large cargo compartment with the flight deck at the nose of the helicopter and a hydraulically operated ramp located at the rear. The cargo area accommodated forty-four combat-equipped infantrymen, or twenty-four litters plus two medical attendants, or large pieces of equipment or vehicles weighing up to 12,000 pounds. A hole in the forward floor of the cabin allowed items to be hoisted into or lowered from the helicopter. An external cargo hook at the center of the helicopter allowed the Chinook to carry large slingloads, up to 28,000 pounds on current models. Like its predecessors, the CH-47’s design placed the three-bladed, counter-rotating, tandem rotor hubs atop pylons at the fore and aft ends of the aircraft. Each articulated rotor system, with blades composed of steel spars, aluminum honeycomb filler, and a plastic-reinforced fiberglass skin, measured 60 feet in diameter. The 67-horsepower auxiliary power unit (APU), combining transmissions for the turbine engines and all associated driveshafts, was installed on top of the fuselage as well. Fairings along the lower exterior of the helicopter housed large fuel tanks, the battery, and other electronic equipment. The landing gear consisted of four fixed struts, the aft set of paired wheels being steerable on the ground but locked in flight.
The Army settled on the Chinook as its primary medium assault transport helicopter, accepting the first delivery in August 1962, and equipped its airmobile test division, the 11th Airborne, with the CH- 47A. When the airmobile division changed to the 1st Cavalry Division (Airmobile), it received the CH-47B with more powerful T55- L-7C engines. On October 14, 1967, the CH-47C appeared with even more powerful T55-L-11A 3,802-horsepower engines, stronger transmissions, a larger capacity fuel system, and an additional attaching point for external cargo. The next spring the U. S. Army began taking deliveries of the “Super C,” as many soldiers called the upgraded Chinook.
In late 1965, in cooperation with the Boeing Corporation, the U. S. Army commenced testing an armed version of the CH-47 Chinook. Engineers mounted an array of weapons on the aircraft, including an M-5 40-mm automatic grenade launcher in a nose turret controlled and fired by the copilot. Pylons on either side of the helicopter accepted forward-firing weapons including a 20-mm cannon and 19-round 2.75-inch rocket pods. A modified fuselage allowed two door-gunners on each side of the cargo compartment to fire a 7.62-mm or .50-caliber machine gun situated on flexible mounts. An additional gunner position located at the rear loading ramp provided protection after the aircraft had completed its “gun run.” One version of the ACH-47 even carried an experimental 105-mm gun. In addition to more than a ton of expendable ammunition, a ton of steel plating and heavily armored seats protected the aircraft crew and vital aircraft components from ground fire. The Army deployed a company of the armed Chinooks to the RVN, with the call sign of “Guns A-Go-Go,” but the USAF AC-130 proved much more effective; the Army withdrew its armed Chinooks from combat.
In May 1970 the Boeing Corporation flew a company funded experiment with a modified Model 114. For the Model 347 Experimental Advanced-Technology Helicopter prototype, Boeing engineers stretched a CH-47A fuselage with a taller aft pylon, installed four-bladed main rotors, a retractable landing gear, and mounted an unconventional lift wing above the center of the fuselage. The experiment proved unfruitful, with no forthcoming orders for the unusual aircraft.
COMBAT SERVICE SUPPORT HELICOPTERS
In the late 1970s the U. S. Army determined that the Boeing CH- 47C no longer met its medium lift requirements. As a result Boeing Vertol modified an existing CH-47A as the prototype for a much improved CH-47D. In May 1979 the prototype took off on its first flight, and in February 1983 the 101st Airborne Division at Fort Campbell, Kentucky, accepted delivery of the first fully modified CH-47D. In April 1985, impressed with the CH-47D’s performance, the Army contracted Boeing Vertol to upgrade all existing “A,” “B,” and “C” model Chinooks to CH-47D standard.
In phases the Army delivered the Chinooks to Boeing’s Ridley, Pennsylvania, facility, where the aircraft were stripped to the airframe and rebuilt. The plant installed two Avco-Lycoming T55-L- 712 turbines, more powerful transmissions, and redesigned composite rotor blades. The refit included computerized flight controls, a new hydraulic system, triple cargo hooks, an improved Auxiliary Power Unit (APU), and a single-point refueling. A dual electronic system powered a completely redesigned instrumentation and avionics suite. From the mid-1980s through the mid-1990s, Boeing transformed all CH-47 airframes into either CH-47D or MH-47E aircraft. Boeing rebuilt and upgraded five Chinooks for Argentina, twelve for Australia, ten for Spain, and nine for Canada, which were later sold to The Netherlands. The company also manufactured new aircraft for the U. S. Army, Australia, and Singapore. Spain and Australia initially received CH-47C aircraft, but shortly after delivery of these machines Boeing Vertol introduced the Model 414 International Chinook, which was quickly upgraded to the Model 414-100, basically a CH-47D.
Apart from the United States, the Royal Air Force ordered and used more Chinooks than any other military. In 1978 the RAF ordered thirty-three aircraft to replace its obsolete Bristol Belvederes. Boeing equipped these HC-1s with T55-L-1 IE turboshafts, the latest avionics, rotor brakes, three cargo hooks, provisions for pressurized refueling, and modifications for internal ferry tanks. In the 1982 Falklands War the Chinooks performed so magnificently that the RAF subsequently ordered another eight Chinooks, which included three to replace those lost on the Atlantic Conveyor support ship. Despite harsh winds and the most miserable weather conditions, the British crews flew their Chinooks day and night, transporting troops, critical supplies, and the badly wounded to hospital ships. Subsequently the Boeing factory upgraded all the RAF Chinooks to CH-47 specifications, designated the HC-2. The RAF also ordered an additional seventeen new aircraft.
In November 1978, Boeing Vertol announced the Model 234, a civilian variant of the Chinook. In August 1980 company test pilots flew the first prototype of four different models offered. The standard airframe accommodated forty-four passengers, but range varied between the 234LR (Long Range), 234ER (Extended Range), 234UT (Utility), and 234 Combi because of supplemental fuel tanks. Boeing installed airline-type windows, a galley, a small toilet, and enlarged external fairings containing the fuel tanks and baggage compartments along the lower fuselage of the BV-234. British Airways Helicopters bought several aircraft for North Sea oil support and carried more than 80,000 passengers in their first year of operation. Columbia Helicopters, ERA Helicopters, and Helicopter Service A. S. of Norway also bought versions of the Chinook. Unfortunately, passengers generally preferred the smaller Puma and Sikorsky S-61N, which led to a relatively short time of service for the Chinooks in North Sea operations.
Coalition forces, led by the United States and the United Kingdom, deployed more than 160 Chinooks to the Persian Gulf for Operation Desert Shield and logged in excess of 16,000 hours of mission time during that conflict. In addition, the armed forces of Canada, Italy, South Korea, and Thailand ordered export versions of the BV-414, most of which received factory upgrading. Between September 1991 and April 1993, Boeing rebuilt eighteen Spanish Army CH-47Cs to meet CH-47D standards. The Netherlands bought seven Canadian Ch-47Cs, and Boeing upgraded them to CH-47s as well. Boeing Vertol also granted a license to manufacture the Chinook to the Italian associate company of Agusta, Elicotteri Meridionali SpA. The consortium produced thirty-four aircraft for the Italian Army and sold several Chinooks to Egypt, Greece, Iran, Libya, and Morocco. In Japan, Kawasaki received a license to build the CH-47J, also a standard CH-47D Chinook, powered by two Mitsubishi-Lycoming T55-K-712 turboshafts. Deliveries of the first of forty-five Chinooks to the JASDF and JGSDF began in 1986.
In the late 1980s, responding to a U. S. Army requirement for a medium lift helicopter for clandestine operations, Boeing produced special operations versions of the CH-47D, the MH-47D, and the follow-on MH-47E. The company revamped the machines with a Model 234 nose section containing a terrain-following radar, an integrated advanced avionics system, and air defense radar jammers. Increasing the self-defense capabilities of the Chinooks, Boeing installed window-mounted 7.62-mm miniguns and Stinger AAM missile racks. The company also added increased fuel capacity and booms for in-flight refueling. On June 1, 1990, SOCOM officially took delivery of the first MH-47D.