By Rob Russell
Manufactured for the United States Air Force (USAF) from the 1980s to the early 1990s by McDonnell Douglas and then Boeing, the Boeing C-17 Globemaster III first flew on September 15th, 1991, in Long Beach, California. Whilst the original specifications required an aircraft to replace the Lockheed C-130 Hercules, Boeing proposed its YC-14 twinjet short take-off and landing (STOL) transport, while McDonnell Douglas put forward its YC-15, a four-engine short take-off, and landing (STOL) tactical transport aircraft.
By 1980, the Air Force was still operating an ageing fleet of C-141 Starlifters and asked McDonnell Douglas to develop a larger plane based on its YC-15, to replace the Starlifter fleet, which was becoming uneconomical to operate. The end result was a larger plane with more powerful engines and a swept-back wing. The newly designed aircraft would give the USAF an aircraft that could carry out work usually undertaken by the C-141 and some duties of the massive Lockheed C-5 Galaxy, leaving the Galaxy available for transporting oversized cargo.
The Air Force told Congress that it needed 210 aircraft, but delays and development costs in the late 1980s began to raise questions about more cost-effective solutions. In April 1990, then Secretary of Defence, Dick Cheney cut the order from 210 aircraft to 120. When the maiden flight took place on September 15, 1991, the program was a year behind schedule.
After the first flight, extensive testing occurred at Edwards Air Force Base in San Bernardino County, California. Now called the "C-17," the plane suffered a setback in October 1992 when its wings buckled during testing. Around $100 million was spent addressing the problem, yet during a second test in September 1993, the wings buckled again when put under pressure. When studying the data following the second test, engineers found that the wing met all the requirements but buckled because the plane had been loaded incorrectly.
In early 1993, the C-17 received another name change and was now called the Globemaster III. Delays and cost overruns, led the Department of Defense telling the contractor that it had two years to sort out the problems and, if not, it was going to cancel its order. By September 1995, most of the issues with the Globemaster III had been resolved, allowing for the first USAF squadron to become operational.
Two years later, McDonnell Douglas merged with Boeing, and the Seattle planemaker offered to cut the price on the C-17, if the government ordered more aircraft. After an initial order for 60 planes, the USAAF asked for a further 120 planes. Eventually, the USAAF ended up with 190 C-17s before US Secretary of Defence Robert Gates announced on April 6, 2009, that there would be no more orders for the C-17.
This, however, proved to be short-lived as on June 12, 2009, the House Armed Services Air and Land Forces Subcommittee asked for 17 more C-17s taking the total number of C-17s in the USAF fleet to 222. In September 2013, Boeing said that they were winding down the production of the C-17 and that the last aircraft built would be delivered in 2015.
During its production run from 1991 to 2015, McDonnell Douglas and Boeing built 279 C-17s for the USAF and other friendly militaries worldwide.C-17 Globemaster IIIs are used by air forces worldwide,
• Royal Air Force
• Royal Australian Air Force
• Royal Canadian Air Force
• Indian Air Force
• Kuwait Air Force
• North Atlantic Treaty Organization (NATO) Strategic Airlift Capability
• Qatar Emiri Air Force
• United Arab Emirates Air Force
• United States Air Force
After all the design and certification problems were sorted out, the C17 has proved to be, after the DC3 and C130 one of the most capable military transport aircraft built. It Is easily adaptable to carry any load, be it cargo or human and has been used for everything from hauling helicopters to logistical cargoes to aeromedical evacuations. The C-17 has also been seen on humanitarian missions like evacuating refugees from war-torn Afghanistan.
The C-17 has a fuselage diameter of 22.5 ft (6.86 m) and can haul 134 passengers or 170,900 pounds of payload. Additionally, the C-17 can carry over 100 paratroopers or para-drop supplies if necessary.
Unlike big military aircraft like the Ilyushin Il-76, and older generation aircraft that preceded the C17, the C-17 cockpit and loadmaster stations have modern multi-function displays. Interlinked to vastly reduce the crew workloads and ultimately reduce crew compliments. The crew can fly the aircraft through a heads-up display (HUD) and with a fighter-pilot-style stick, the C17 being the first heavy military transport aircraft to do away with the traditional control column. The C17 is crewed by two pilots and the need to carry a flight engineer and navigator has been done away with, thanks to modern EFIS displays, electronic engine monitoring systems and up-to-date navigation systems.
The C-17 can easily land on an airfield as short as 3,500 feet (1,064 meters) and only 90 feet wide (27.4 meters). The C-17 has four Pratt & Whitney PW2040 turbofan engines generating 40,440 pounds of thrust each. Taking off again at that runway distance, which is well within the C-17’s capabilities, does require a significant reduction from 160,000 pounds of payload it could bring to that small airfield – still less than the maximum capability of 170,900 pounds (77,519 kilograms, 77.5 metric tons). At full payload capability, the C-17 requires 7,740 ft. (2,359.15 m) of runway. The C17 is able to be refuelled in flight, which enables it to have an unlimited range. It is not uncommon to see them take off from rough short strips, with just enough fuel to get to a tanker, be re-fuelled and fly across several continents to deliver their loads.
The success of the C-17’s STOL capabilities is the complex high wing and T-tail both designed to be used optimally to ensure such operations. Another is the wing area is 3,800 sq. ft. (353 sq. m), To support arguably the C-17's best manoeuvrability characteristics, the massive flaps that extend behind the engines enable unbeatable take-off and landing performances.
Specifications and general characteristics
Crew: 3 (2 pilots, 1 load-master)
Capacity: 170,900 lbs of cargo distributed at max over 18 463L master pallets or a mix of palletized cargo and vehicles. 102 paratroopers or 134 troops with palletized and sidewall seats or 54 troops with sidewall seats (allows 13 cargo pallets) only or 36 litter and 54 ambulatory patients and medical attendants or cargo, such as one M1 Abrams tank, two Bradley armoured vehicles, or three Stryker armoured vehicles
Length: 174 feet
Wingspan: 169 feet 9.6 inches
Height: 55 feet 1 inch
Wing area: 3,800 square feet
Empty weight: 282,500 lbs
Max takeoff weight: 585,000 lbs
Fuel capacity: 35,546 US gallons
Powerplant: 4 × Pratt & Whitney F117-PW-100 turbofan engines, 40,440 lbf (179.9 kN) thrust each
Cruise speed: 450 knots (520 mph)
Range: 2,780 miles
Service ceiling: 45,000 feet
Takeoff run at MTOW: 8,200 feet
Landing distance: 3,500 feet with maximum payload
