Science Fair Project Encyclopedia
C-17 Globemaster III
|C-17 Globemaster III|
The C-17 Globemaster III
|Role||Cargo and Troop Transport|
|Crew||Three (2 Pilots, 1 Loadmaster)|
|Entered service||June 1993|
|Manufacturer||Boeing Integrated Defense Systems|
|Length||174 ft||53 m|
|Wingspan||169.8 ft||58 m|
|Height||55.1 ft||16.8 m|
|Wing area||3,800 ft²||353 m²|
|Cargo hold dimensions||68.2 × 18 × 12.3 ft||20.8 × 5.5 × 3.8 m|
|Maximum takeoff||585,000 lb (current)|
630,000 lb. (in testing)
|Cargo||170,900 lb||77,500 kg|
|Capacity||102 troops/paratroops; 36 litter and 54 ambulatory patients with attendants|
|Engines||4 × Pratt and Whitney F117-PW-100 turbofan engines|
|Thrust||40,440 lbf||180 kN|
|Maximum speed||450 knot||830 km/h|
|Combat range||2,400 nautical mile (base)|
2,800 nautical mile (ER)
|Ferry range||6,250 nautical mile||11,600 km|
|Service ceiling||45,000 ft||13,700 m|
|Rate of climb||ft/min||m/min|
The C-17 Globemaster III is the newest, most flexible cargo aircraft to enter the airlift force. The C-17 is capable of rapid strategic delivery of troops and all types of cargo to main operating bases or directly to forward bases in the deployment area. The aircraft is also capable of performing tactical airlift and airdrop missions when required. The inherent flexibility and performance of the C-17 force improve the ability of the total airlift system to fulfill the worldwide air mobility requirements of the United States.
The ultimate measure of airlift effectiveness is the ability to rapidly project and sustain an effective combat force close to a potential battle area. Threats to U.S. interests have changed in recent years, and the size and weight of U.S. mechanized firepower and equipment have grown in response to improved capabilities of potential adversaries. This trend has significantly increased air mobility requirements, particularly in the area of large or heavy outsize cargo. As a result, newer and more flexible airlift aircraft are needed to meet potential armed contingencies, peacekeeping or humanitarian missions worldwide. The C-17 is capable of meeting today's demanding airlift missions.
Reliability and maintainability are two outstanding benefits of the C-17 system. Current operational requirements impose demanding reliability and maintainability. These requirements include an aircraft mission completion success probability rate of 92 percent, only 20 aircraft maintenance man-hours per flying hour, and full and partial mission availability rates of 74.7 and 82.5 percent, respectively. The Boeing warranty assures these figures will be met.
The aircraft is powered by four, fully reversible, Federal Aviation Administration–certified F117-PW-100 turbofan engines (the military designation for the commercial Pratt and Whitney PW2040), currently used on the Boeing 757. Each engine is rated at 40,440 lbf (180 kN) of thrust. The thrust reversers direct the flow of air upward and forward to avoid ingestion of dust and debris. Maximum use has been made of off-the-shelf and commercial equipment, including Air Force–standardized avionics.
The aircraft is operated by a crew of three (pilot, copilot, and loadmaster), reducing manpower requirements, risk exposure and long-term operating costs. Cargo is loaded onto the C-17 through a large aft door that accommodates military vehicles and palletized cargo. The C-17 can carry virtually all of the Army's air-transportable equipment.
Maximum payload capacity of the C-17 is 170,900 lb (77,519 kg), and its maximum gross takeoff weight is 585,000 lb (265,352 kg). With a payload of 160,000 lb (72,575 kg) and an initial cruise altitude of 28,000 ft (8,500 m), the C-17 has an unrefueled range of approximately 2,400 nautical miles (4,400 km) on the first 71 units, and 2,800 nautical miles (5,200 km) on all subsequent units, which are extended-range models with an additional fuel tank in the center wing box. Its cruise speed is approximately 450 knots (833 km/h) (.74 Mach). The C-17 is designed to airdrop 102 paratroopers and equipment.
The design of the aircraft allows it to operate through small, austere airfields. The C-17 can take off and land on runways as short as 3,000 ft (900 m) and only 90 ft (27 m) wide. Even on such narrow runways, the C-17 can turn around using a three-point star turn and its backing capability.
The C-17 was designed and created by what was then McDonnell-Douglas (the company and project were taken over by Boeing later in the decade.) It was based upon an earlier McDonnell-Douglas product, the YC-15. This aircraft was the result of a runoff with the Boeing YC-14 in the Advanced Medium STOL Transport project. However, the project was canceled before a winner was selected.
By the early-1980s, the USAF found itself with a very large, but aging fleet of C-141 Starlifters. Some of the C-141s had major structural problems as a result of heavy use. USAF also has historically never had sufficient strategic airlift capabilities to fulfill its requirements. They elected to use the YC-15 as the basis for a new aircraft. This aircraft, by then designated the C-17A Globemaster III was ordered in August 1981. The new aircraft differed in having swept wings, increased size, and more powerful engines. This would allow it to perform all work performed by the C-141, but to also fulfill some of the duties of the C-5 Galaxy, so that the C-5 fleet would be freed up for larger, more outsize cargo.
Development continued until December, 1985 when a full-scale production contract was signed. Its maiden flight was on September 15, 1991 from the McDonnell-Douglas west coast plant in Long Beach, California. This aircraft and five more production models participated in flight testing and evaluation.
The first production model was delivered to Charleston Air Force Base, S.C., on July 14, 1993. The first squadron of C-17s, the 17th Airlift Squadron , was declared operationally ready on January 17, 1995.
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 for Special Operations Command. Basing of the original 120 C-17s is planned for Charleston AFB ; McChord AFB (first aircraft arrived in July 1999); Altus AFB; and at an Air National Guard unit in Jackson, Miss. Basing of the additional 14 aircraft has not been determined. An additional 60 units were ordered in May of 2002. The Department of Defense is considering an additional 42 aircraft. Depending upon the fate of the C-5 Galaxy, there may be further orders.
USAF originally intended to acquire about 350 units, though this was reduced at the end of the Cold War. However, USAF has been so pleased with the aircraft that it is entirely possible that the C-17 will be ordered in greater quantities than originally envisioned, with current orders standing at 180, and likely to reach 222 in the near future. In order to avoid disruption of the production line in U.S. FY2006, USAF will have to make a decision on the 42-aircraft buy in early 2005.
The C-17 is operated by the Air Mobility Command at the 437th Airlift Wing , Charleston AFB, S.C.; the 62nd Airlift Wing , McChord AFB, Wash; and the 315th Airlift Wing (Associate Reserve), Charleston AFB, S.C.
Boeing has actively marketed the C-17 to many European nations including Belgium, Britain, France, and Spain. Of these, Britain was always seen as the most likely customer given its increasingly expeditionary military strategy and global commitments. The Royal Air Force, while unable to achieve parity with the United States Air Force, has established an aim of at least having interoperability and some weapons and capabilities commonality. The UK's 1998 Strategic Defence Review identified a requirement for a strategic airlifter following the protracted procurement of the European airlifter, the Airbus A400M. The Short-Term Strategic Airlift (STSA) competition commenced in September of that year. The UK cancelled the competition in August 1999 recognizing that the C-17 was the only aircraft that met its demanding specifications.
The UK Defence Secretary, Geoff Hoon, announced in May 2000 that the RAF would lease four C-17s 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 the C-17s in line with the USAF so that in the event of them being returned to Boeing the USAF could adopt them.
The first C-17 was delivered to the RAF at Boeing's Long Beach facility on May 17, 2001 and flown to RAF Brize Norton by 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 August 24, 2001. The RAF aircraft were some of the first to take advantage of the new centre wing fuel tank.
The RAF declared itself delighted with the C-17 and reports began to emerge that they wished to retain the aircraft regardless of the A400M's progress. Although the C-17 fleet was to be a fallback for the A400M, the UK announced on July 21, 2004 that they have elected to buy their four C-17s at the end of the lease, even though the A400M is moving towards production. They will also be placing a follow-on order for one aircraft, though there may be additional purchases later, especially if the A400M does not live up to expectations in operational use. While the A400M is described as a "strategic" airlifter, the C-17 gives the RAF true strategic capabilities that it would not wish to lose, for example a maximum payload of 77,000 kg compared to the Airbus' 37,000 kg. The fifth aircraft will be ordered when the USAF places its expected order for 42, in early 2005.
In RAF service the C-17 has not been given an official designation (e.g. C-130J referred to as Hercules C4 or C5) due to its leased status, but is referred to simply as the C-17. Following the end of the lease period the four aircraft will assume an RAF designation, most likely "Globemaster C1." Presumably, should the additional aircraft enter service prior to this, it alone will carry the C1 designation for a time.
The 2004 Indian Ocean earthquake and resultant tsunamis placed a strain on the global strategic airlifter pool. The impressive performance of the C-17 in USAF and RAF service have persuaded Germany to consider acquiring 2-4 C-17s for the Luftwaffe in a dry lease arrangement, at least until the A400M is available in 2009. German Foreign Minister Joschka Fischer stated in the German news magazine Der Spiegel that the government needed its own organic strategic transport capability to be able to respond to disasters in a better manner than it was able to for this incident. During the tsunami relief effort, Germany tried to acquire transport through its usual method of wet leasing Antonov airlifters via private companies, but found to its dismay that there were no available aircraft. While the stated goal of a C-17 lease would be to last until the A400M's arrival, it is always possible that the Luftwaffe may undergo an experience similar to that of the RAF, and elect to retain them.
The C-17 was used to deliver military goods and humanitarian aid during Operation Enduring Freedom in Afghanistan as well as Operation Iraqi Freedom in Iraq by both services. On March 26, 2003, ten USAF C-17s participated in the biggest combat airdrop since Operation Just Cause in Panama in December, 1989. The night-time airdrop of 1,000 soldiers occurred over Bashur, Iraq. It opened the northern front to combat operations and constituted the largest formation airdrop since D-Day in World War II.
Units using the C-17
United States Air Force
- Altus AFB
- 97th Air Mobility Wing
- 58th Airlift Squadron
- 97th Air Mobility Wing
- Charleston AFB
- 315th Airlift Wing
- 300th Airlift Squadron
- 317th Airlift Squadron
- 701st Airlift Squadron
- 315th Airlift Wing
- March ARB
- McChord AFB
- 62nd Airlift Wing
- 4th Airlift Squadron
- 7th Airlift Squadron
- 8th Airlift Squadron
- 446th Airlift Wing
- 97th Airlift Squadron
- 313th Airlift Squadron
- 728th Airlift Squadron
- 62nd Airlift Wing
- McGuire AFB
- Allen C. Thompson Field ANGB
- 172nd Airlift Wing
- 183rd Airlift Squadron
- 172nd Airlift Wing
Royal Air Force
Inventory: 4 C-17ER (+1 C-17ER on order)
|Modern USAF Series|
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details