The Boeing CH-47 Chinook is a heavy lift helicopter that first saw service in 1962 and is still serving its country today. It is unique, powerful, reliable and has seen service in almost every military theater since its introduction. It is also the longest running production model in Boeing’s inventory.
In 1958, the Army commissioned Vertol to design a transport helicopter that could lift 2000Kg in all weathers. The answer was the Model 107 and Model 114. In 1960, Boeing bought Vertol and took over development and production of the airframes.
The first Model 107 had two 877hp Lycoming T53 turbine engines and took flight in August 1958. The Army ordered 10 of these and designated it the YHC-1A. The YHC-1B was based on the Model 114, which was larger. At the same time, the Navy ordered modified versions of the YHC-1A, the 107M which was designated the CH-46A Sea Knight.
The original concept was created by Frank Piasecki, who worked for the Vertol Aircraft Corporation. The banana-shaped aircraft proved very efficient, offering a lot of cargo space and heavy-lift capability in a relatively small fuselage. The placing of the engines above the fuselage added to the available space.
The design builds the helicopter around the cargo bay, with engines on top and flight deck in front. This way of designing the aircraft has since been used in cargo vehicles ever since as it provide so popular and so effective in this helicopter. The addition of a hydraulic cargo ramp at the back offers fast loading and unloading as well as the potential for fast troop deployment.
The cargo bay has a volume of around 42m3 and can carry 44 troops, 24 stretchers, or cargo up to 11 tons in weight. The helicopter can also mount a side winch by the starboard door or a cargo hook underneath the fuselage on a hard point.
After the trials, five CH-47 Chinooks were ordered, with increases upon the arrival of the CH-47B. The CH-47C saw more powerful engines in the 3802hp T55-L-11A’s, a stronger transmission and larger fuel capacity. The first CH-47C Chinook flew in October 1967 and was quickly sent to Vietnam to provide much of the heavy lift capacity for the Army.
Chinooks that had been serving during the Vietnam War accrued almost 161,000 hours by the end of 1968. The three variants A, B and C all flew with incredible distinction throughout the Vietnam war until 1975.
Almost as soon as the war was over, the development of the CH-47D began. This included bigger, more powerful engines, night vision capability, increased cargo capacity, increased lift weight capability, modern avionics, more fuel and better all-round performance. When finally complete, the CH-47D could carry the same load as any three cargo helicopters in service.
Specific improvements included new T55-L-712 turboshafts, uprated transmission with integral lubrication and cooling, new composite rotor blades, new flight deck, new redundant electrical system, modular hydraulic system, advanced automatic flight controls and the addition of two further cargo hooks.
The CH-47D first flew in 1979, with production starting in 1980 with first delivery in March 1982.
Further modified CH-47 Chinook helicopters have entered service, including the MH-47E, a special forces variant with air-to-air refueling capability and a longer nose. It also included larger fuel tanks, better avionics, improved navigation, more capable communications and a pair of miniguns by each cargo door.
The MH-47E is subject to a current modernization program which will see it brought in line with the CH-47F, with further improved avionics, communications, better engines, vibration damping and digital mission management systems. The CH-47F is a current program to modernize the Chinook fleet and will see all current CH-47D modified to F and the addition of 55 new model F aircraft.
Throughout its history, the CH-47 Chinook has served wherever our troops and the armies of our allies have served. They served will in Vietnam and during the Iran-Iraq War where we sold them to the Iranian Air Force.
They served the British exceptionally well in the challenging Falklands War in 1982. They ferried troops and supplies from the Royal Navy ashore to the Falklands Islands despite some truly appalling weather conditions. Two were also used by the Argentinians as troop transports, where one was destroyed and the other captured.
The CH-47 Chinook helicopter is one of the most, if not the most, successful helicopter of its kind anywhere in the world. There are civilian models, special forces variants and licensed versions used throughout the world. It is used extensively by America and her allies, including Argentina, Australia, the United Kingdom, Singapore, Saudi Arabia and many more countries.
With a multi-million dollar modernization program underway, the CH-47 Chinook is likely to be serving our armed forces for decades to come. That means that familiar “whop-whop” of its twin rotors will be heard for many years yet.