The Boeing C-17 Globemaster III is a large military transport aircraft. It was developed for the United States Air Force (USAF) from the 1980s to the early 1990s by McDonnell Douglas; the company later merged with Boeing. The C-17 is used for rapid strategic airlift of troops and cargo to main operating bases or forward operating bases throughout the world. It can also perform tactical airlift, medical evacuation and airdrop missions. The C-17 carries the name of two previous, but unrelated piston-engine, U.S. military cargo aircraft, the Douglas C-74 Globemaster and the Douglas C-124 Globemaster II. In addition to the U.S. Air Force, the C-17 is operated by the United Kingdom, Australia, Canada, Qatar, United Arab Emirates and NATO Heavy Airlift Wing. Additionally, India has ordered C-17s. Development Background and design phase In the 1970s, the U.S. Air Force began looking for a replacement for its Lockheed C-130 Hercules tactical cargo aircraft.[2] The Advanced Medium STOL Transport (AMST) competition was held, with Boeing proposing the YC-14, and McDonnell Douglas proposing the YC-15.[3] Though both entrants exceeded specified requirements, the AMST competition was canceled before a winner was selected. The Air Force started the C-X program in November 1979 to develop a larger AMST with longer range to augment its strategic airlift.[4] The McDonnell Douglas YC-15 design was used as the basis for the C-17. By 1980, the USAF found itself with a large fleet of aging C-141 Starlifter cargo aircraft. Compounding matters, USAF needed increased strategic airlift capabilities to fulfill its rapid-deployment airlift requirements. The USAF set mission requirements and released a request for proposals (RFP) for C-X in October 1980. McDonnell Douglas elected to develop a new aircraft based on the YC-15; Boeing bid an enlarged three-engine version of its AMST YC-14. Lockheed submitted two designs, a C-5-based design and an enlarged C-141 design. On 28 August 1981, McDonnell Douglas was chosen to build its proposed aircraft, then designated C-17. Compared to the YC-15, the new aircraft differed in having swept wings, increased size, and more powerful engines.[5] This would allow it to perform the work done by the C-141, and also fulfill some of the duties of the Lockheed C-5 Galaxy, freeing the C-5 fleet for outsize cargo.[5] Alternate proposals were pursued to fill airlift needs after the C-X contest. These were lengthening of C-141As into C-141Bs, ordering more C-5s, continued purchases of KC-10s, and expansion of the Civil Reserve Air Fleet. Limited budgets reduced program funding, requiring a delay of four years. During this time contracts were awarded for preliminary design work and for the completion of engine certification.[6] In December 1985 a full-scale development contract was awarded.[7] At this time, first flight was planned for 1990.[6] The Air Force had formed a requirement for 210 aircraft.[8] Development problems and limited funding caused delays in the late 1980s.[9] Criticisms were made of the developing aircraft and questions were raised about more cost-effective alternatives during this time.[10][11] In April 1990, Secretary of Defense Dick Cheney reduced the order from 210 to 120 aircraft.[12] The maiden flight of the C-17 took place on 15 September 1991 from the McDonnell Douglas's plant in Long Beach, California, about a year behind schedule.[13][14] The first aircraft (T-1) and five more production models (P1-P5) participated in extensive flight testing and evaluation at Edwards Air Force Base.[15] Two complete airframes were built for static and repeated load testing.[14] Development difficulties A static test of the C-17 wing in October 1992 resulted in the wing failing at 128% of design limit load, which was below the 150% requirement. Both wings buckled rear to the front and failures occurred in stringers, spars and ribs.[16] Some $100 million was spent to redesign the wing structure; the wing failed at 145% during a second test in September 1993.[17] A careful review of the test data however, showed that the wing was not loaded correctly and did indeed meet the requirement.[18] The C-17 received the "Globemaster III" name in early 1993.[5] In late 1993, the Department of Defense gave the contractor two years to solve production and cost overrun problems or face termination of the contract after the delivery of the 40th aircraft.[19] By accepting the 1993 terms, McDonnell Douglas incurred a loss of nearly US$1.5 billion on the development phase of the program.[15] In April 1994, the C-17 program remained over budget, and did not meet weight, fuel burn, payload and range specifications. It also failed several key criteria during tests to evaluate its airworthiness.[20][21][22] There were technical problems with mission software, landing gear, and so on.[23] In May 1994, a proposal to cut the aircraft's production to as few as 32 aircraft emerged, but was rescinded.[24] A July 1994 GAO document revealed that Air Force and DoD studies from 1986 and 1991 stated the C-17 could use 6,400 more runways outside the U.S. than the C-5; it was later discovered that this study had only considered the runway dimensions, but not their strength or Load Classification Numbers (LCN). The C-5 has a lower LCN, but the USAF classify both in the same broad Load Classification Group (LCG). When considering runway dimensions and their load ratings, the C-17's worldwide runway advantage over the C-5 shrank from 6,400 to 911 airfields.[25] However, the C-17's ability to use lower quality, austere airfields was not considered.[25] A January 1995 GAO report revealed that while the original C-17 budget was $41.8 billion for 210 aircraft, the 120 aircraft already ordered at that point had already cost $39.5 billion.[26] In March 1994, the U.S. Army had decided it no longer needed the 60,000 lb (27,000 kg) Low Altitude Parachute Extraction System (LAPES) delivery with the C-17, feeling that the 42,000 lb (19,000 kg) capability of the C-130 was sufficient; C-17 testing was limited to this lower weight. Issues with airflow prevented the C-17 from meeting its airdrop requirements. A February 1997 GAO report revealed that a C-17 with a full payload could not land on 3,000 ft (910 m) wet runways; simulations suggested 5,000 ft (1,500 m) was required.[27] The YC-15 was transferred to AMARC to be made flightworthy again for further flight tests for the C-17 program in March 1997.[28] By the mid-1990s, most of the problems had been resolved.[29][30] The first C-17 squadron was declared operational by the U.S. Air Force in January 1995.[31] In 1996, DoD ordered another 80 aircraft for a total of 120.[32] In 1997 McDonnell Douglas merged with its former competitor, Boeing. In April 1999, Boeing proposed to cut the price of the C-17 if the Air Force bought 60 more,[33] and in August 2002, the order was increased to 180 aircraft.[34] Continued production Due to a dwindling order backlog, Boeing was to deliver 13 C-17s in 2011. The company is transitioning to a lower production rate of 10 C-17s per year, from a high of 16 per year, to extend the production line through 2012 as it works to sign additional international orders. The C-17 production line was previously slated to be closed several times, but was extended due to new orders received. The C-17 workforce will be reduced by approximately 1,100 through the end of 2012, mostly through the elimination of a second shift at the C-17 final assembly plant in Long Beach.[35][36] There had been 230 production C-17s delivered, including 210 to the USAF, by April 2011.[37] This does not include the "T-1" prototype, which was used by the USAF for testing and development before its retirement in 2012.[38] In January 2010, the USAF announced that it would end Boeing's performance-based logistics contracts to maintain the aircraft, which was a key source for projected profit growth for the company.[39] Design The C-17 is 174 feet (53 m) long and has a wingspan of about 170 feet (52 m). It can airlift cargo fairly close to a battle area. The size and weight of U.S. mechanized firepower and equipment have grown in recent decades from increased air mobility requirements, particularly for large or heavy non-palletized outsize cargo. The C-17 is powered by four Pratt & Whitney F117-PW-100 turbofan engines, which are based on the commercial Pratt and Whitney PW2040 used on the Boeing 757. Each engine is fully reversible and rated at 40,400 lbf (180 kN) of thrust. The thrust reversers direct engine exhaust air upwards and forward, reducing the chances of foreign object damage by ingestion of runway debris, and providing enough reverse thrust to back the aircraft up on the ground while taxiing. The thrust reversers can also be used in flight at idle-reverse for added drag in maximum-rate descents. The aircraft requires a crew of three (pilot, copilot, and loadmaster) for cargo operations. Cargo is loaded through a large aft ramp that accommodates rolling stock, such as a 69-ton (63-metric ton) M1 Abrams main battle tank, other armored vehicles, trucks, and trailers, along with palletized cargo. The cargo compartment is 88 feet (26.82 m) long by 18 feet (5.49 m) wide by 12 feet 4 inches (3.76 m) high. The cargo floor has rollers for palletized cargo that can be flipped to provide a flat floor suitable for vehicles and other rolling stock. Maximum payload of the C-17 is 170,900 lb (77,500 kg), and its Maximum Takeoff Weight is 585,000 lb (265,350 kg). With a payload of 160,000 lb (72,600 kg) and an initial cruise altitude of 28,000 ft (8,500 m), the C-17 has an unrefueled range of about 2,400 nautical miles (4,400 km) on the first 71 aircraft, and 2,800 nautical miles (5,200 km) on all subsequent extended-range models that include sealed center wing bay as a fuel tank. Boeing informally calls these aircraft, the C-17 ER.[40] The C-17's cruise speed is about 450 knots (833 km/h) (Mach 0.74). It is designed to airdrop 102 paratroopers and their equipment.[41] The U.S. Army's Ground Combat Vehicle is to be transported by the C-17. The C-17 is designed to operate from runways as short as 3,500 ft (1,064 m) and as narrow as 90 ft (27 m). In addition, the C-17 can operate from unpaved, unimproved runways (although with greater chance of damage to the aircraft).[41] The thrust reversers can be used to back the aircraft and reverse direction on narrow taxiways using a three- (or more) point turn.[41] Operational history United States Air Force The first production model was delivered to Charleston Air Force Base, South Carolina on 14 July 1993. The first squadron of C-17s, the 17th Airlift Squadron, was declared operationally ready on 17 January 1995.[42] The C-17 has broken 22 records for oversized payloads.[43] The C-17 was awarded US aviation's most prestigious award, the Collier Trophy in 1994.[44] A report to Congress detailing operations in Kosovo and Operation Allied Force noted that "One of the great success stories...was the performance of the Air Force's C-17A"[45] The C-17 flew half of the strategic airlift missions required in the operation. The aircraft allowed for deliveries via small airfields, greatly assisting the deployment; and rapid turnaround times allowed for efficient utilization.[46] The Air Force originally programmed to buy a total of 120 C-17s, with the last one being scheduled for delivery in November 2004. The fiscal 2000 budget funded another 14 aircraft, primarily for Air Mobility Command (AMC) support of the United States Special Operations Command (USSOCOM). Basing of the original 120 C-17s was with the 437th Airlift Wing and 315th Airlift Wing at Charleston AFB, South Carolina, the 62nd Airlift Wing and 446th Airlift Wing at McChord Air Force Base, Washington (first aircraft arrived in July 1999), the Air Education and Training Command's (AETC) 97th Air Mobility Wing at Altus AFB, Oklahoma, and the Air Mobility Command-gained 172nd Airlift Wing of the Mississippi Air National Guard at Jackson-Evers International Airport/ANGB, Mississippi. Although belonging to the Air Mobility Command, the C-17s of the 172 AW are controlled by the Air National Guard (ANG).[citation needed] Basing of the additional 13 aircraft went to the 305th Air Mobility Wing and 514th Air Mobility Wing at McGuire Air Force Base, New Jersey; the 3rd Wing and 176th Wing at Elmendorf Air Force Base, Alaska; 15th Airlift Wing and 154th Wing at Hickam Air Force Base, Hawaii; and 60th Air Mobility Wing and 349th Air Mobility Wing at Travis Air Force Base, California. An additional 60 units were ordered in May 2002. In FY 2006, eight C-17s were delivered to March Joint Air Reserve Base, California; to be controlled by the Air Force Reserve Command (AFRC). In 2007, Congress appropriated funds for 10 additional USAF C-17s, bringing the total planned fleet size to 190. Additional aircraft were subsequently assigned to Dover Air Force Base, Delaware, previously equipped with Lockheed C-5 Galaxy aircraft.[citation needed] The C-17 have been, and continue to be, used to deliver military goods and humanitarian aid during Operation Enduring Freedom in Afghanistan as well as Operation Iraqi Freedom in Iraq. On 26 March 2003, 15 USAF C-17s participated in the biggest combat airdrop since the United States invasion of Panama in December 1989: the night-time airdrop of 1,000 paratroopers from the 173rd Airborne Brigade occurred over Bashur, Iraq. The airdrop of paratroopers were followed by C-17s ferrying M1 Abrams, M2 Bradleys, M113s and artillery.[47] USAF C-17s have also been used to assist allies in their airlift requirements, including Canadian vehicles to Afghanistan in 2003 and the deployment of Australian forces during the Australian-led military deployment to East Timor in 2006. In late 2006, USAF C-17s flew 15 Canadian Leopard C2 tanks from Kyrgyzstan into Kandahar in support of the NATO mission in Afghanistan. A C-17 accompanies the President of the United States on his visits to both domestic and foreign arrangements, consultations, and meetings. The C-17 is used to transport the Presidential Limousine and security detachments.[48] There have been several occasions where a C-17 has been used to transport the President himself, temporarily gaining the Air Force One call sign while doing so.[49] The C-17 and its crews support Special Operations use, including low-level operations, insertion and extraction or resupply support to Special Operations Forces, air drop of supplies, and insertion of paratroops.[citation needed] There has been debate about follow-on orders for the C-17, with the Air Force requesting line shutdown, and members of Congress attempting to reinstate production. Furthermore, in FY2007, the Air Force requested $1.6 billion to deal with what it termed "excessive combat use" on operational airframes.[50] However, in testimony before a House of Representatives subcommittee on air and land forces, General Arthur Lichte, USAF, the Commander of Air Mobility Command indicated the need to extend production to another 15 aircraft to increase the total to 205. Pending the delivery of the results of two studies in 2009, Lichte considered that the Air Force may have to keep the production line open for purchase of even more C-17s to satisfy airlift requirements.[51] ]Royal Air Force Boeing has marketed the C-17 to many European nations including Belgium, Germany, France, Italy, Spain and the United Kingdom. The Royal Air Force (RAF) has established an aim of having interoperability and some weapons and capabilities commonality with the USAF. The UK's 1998 Strategic Defence Review identified a requirement for a strategic airlifter. The Short-Term Strategic Airlift (STSA) competition commenced in September of that year, however tendering was canceled in August 1999 with some bids identified by ministers as too expensive, including the Boeing/BAe C-17 bid, and others unsuitable.[52] The project continued, with the C-17 seen as the favorite.[52] In the light of continuing delays to the Airbus A400M program, the UK Defence Secretary, Geoff Hoon, announced in May 2000 that the RAF would lease four C-17s at an annual cost of £100 million[50] from Boeing for an initial seven years with an optional two year extension. At this point the RAF would have the option to buy the aircraft or return them to Boeing. The UK committed to upgrading its C-17s inline with the USAF so that if they were to be returned to Boeing, the USAF could adopt them. The first C-17 was delivered to the RAF at Boeing's Long Beach facility on 17 May 2001 and flown to RAF Brize Norton by a crew from No. 99 Squadron which had previously trained with USAF crews to gain competence on the type. The RAF's fourth C-17 was delivered on 24 August 2001. The RAF aircraft were some of the first to take advantage of the new center wing fuel tank found in Block 13 aircraft. In RAF service, the C-17 has not been given an official designation (for example, C-130J referred to as Hercules C4 or C5), but is referred to simply as the C-17 or "C-17A Globemaster". The RAF declared itself delighted with the C-17. Although the Globemaster fleet was to be a fallback for the A400M, the Ministry of Defence (MoD) announced on 21 July 2004 that they had elected to buy their four C-17s at the end of the lease,[53] even though the A400M appeared to be moving closer to production. While the A400M is described as a "strategic" airlifter, the C-17 gives the RAF strategic capabilities that it would not wish to lose, for example a maximum payload of 169,500 lb (77,000 kg) compared to the A400M's 82,000 lb (37,000 kg).[50] Another C-17 was ordered in August 2006, and delivered on 22 February 2008. The four leased C-17s were to be purchased later in 2008.[54] Due to fears that the A400M may suffer further delays, the MoD announced in 2006 that it planned to acquire three more C-17s, for a total of eight, with delivery in 2009–2010. On 26 July 2007, Defence Secretary Des Browne announced that the MoD intended to order a sixth C-17 to boost operations in Iraq and Afghanistan.[55] On 3 December 2007, the MoD announced a contract for a sixth C-17,[56] which was received on 11 June 2008.[57] On 18 December 2009, Boeing confirmed that the RAF had ordered a seventh C-17,[58][59] which was delivered on 16 November 2010.[60] The UK announced the purchase of its 8th C-17 in February 2012.[61]