C-17 Globemaster III Description
The C-17 Globemaster III is a high-wing, four-engine, T-tailed aircraft with a rear loading ramp. In 1980, the U.S. Air Force asked for a larger transport that could be refueled in flight and use rough forward fields so that it could fly anywhere in the world. On Aug. 28, 1981, McDonnell Douglas won the contract with its proposal to build the C-17. The design met or exceeded all Air Force needs.
The C-17 is the only transport aircraft with an intercontinental range capable of landing at austere airfields, The C-17 can carry large equipment, supplies and troops directly to small austere airfields in harsh terrain anywhere in the world day or night. The aircraft also has the ability to conduct airdrops of cargo or troops when required.
Integrated avionics architecture for flight navigation and control is designed for high sortie generation rates. The aircraft can be serviced and operated easily without special equipment – this is designed to reduce the logistics footprint for the Air Force, and to lower ownership costs.
The C-17 employs a fly-by wire control system similar in operation to that of the 787, which Boeing says will ensure ease of control and reduce the work load on pilots.
The C-17 is the second largest military transport in US Air Force service (the largest being the even larger Airbus A380-800). The Boeing 747, one variant of which is used as Air Force One, is longer than the C-17 Globemaster III.
The C-17 can carry large equipment, supplies and troops directly to small austere airfields in harsh terrain anywhere in the world day or night. The aircraft also has the ability to conduct airdrops of cargo or troops when required. Paratroopers, their gear and supplies are delivered to any location on short notice. As an example, paratroop-configured C-17s have landed at the base in Antarctica.
A full load of 42 fully equipped troops can be accommodated in the main cargo compartment, or up to 102 troops can be carried in a “10-by-90” configuration. A typical “10-by-90” configuration would consist of a containerized ICU patient plus ten patients each seated on two seats, eight medical litters and six seats for accompanying company-grade officers or below.
Cargo that has been unpacked and is ready to be loaded onto trucks, can be loaded onto the C-17 in approximately half the time it takes to load cargo onto a C-5 Galaxy or C-141 Starlifter. The C-17 also has an advantage over the C-5 and the C-130 in that it can use “kneeling landing gear”, which allows cargo to be driven directly from the cargo compartment onto a truck. Ground crews also have the option of using a built-in scissors-lift, also known as a “Mast Basket” to load and unload cargo directly on and off the aircraft. This is especially useful in situations where a forklift is not convenient. In such cases, the C-17’s loadmaster typically operates the scissors lift while standing on the front landing gear assembly and hand-signals directions to ground crews maneuvering the cargo into place at the aircraft’s rear. This process only takes 20 minutes from start to finish, allowing a return flight to be made without having to leave the aircraft.
The C-17 is also easier and faster in cargo loading and unloading than the larger, slower, and lower-flying C-141. A pallet of cargo weighing approximately , or an M1152 HMMWV can be loaded and unloaded in as little as three minutes.
The C-17’s maximum payload is . This is twice the capacity of the early 1990s General Dynamics YC-15, which was found to be less satisfactory than expected. The C-17 is also able to deliver M119 howitzers and other oversized cargo externally.
The C-17 is capable of carrying a single, long, wide combat vehicle such as an M1 Abrams tank or M2/M3 Bradley IFV. In the case of carrying a single vehicle, this would require folding down one or more sections of seats in the cargo compartment to make room. If additional room is needed, the C-17 can carry two smaller vehicles instead of one large vehicle, since the space is slightly more than 36 feet (11 m) long, this leaves some empty space on the top.
The C-17 has an overall cargo-bay length of and has a fully loaded internal bay which is long, high and wide at the forward bulkhead. The cargo floor is wide and high. The rear cargo doors open to the side, like on the Douglas C-54 and the Boeing-Stearman Model 75; in this arrangement, vehicles can drive straight into and out of the cargo bay. When the rear cargo doors open to the front (i.e., 90 degrees) on ground, a ramp can be lowered to allow rolling stock (railroad cars, for example) to be loaded and unloaded more rapidly. The C-17 can carry either six pallets and a single container or one roll on/roll off (RoRo) vehicle in addition to six pallets. The United States Air Force found that a C-17 could carry two M1 main battle tanks, but the Army for a time was limited to one M1 per C-17, due to runway load restrictions at certain airfields.
The cargo floor is smooth enough for easy loading and unloading of palletized cargo. The wings were designed with a large 10-degree anhedral (downward slope) to meet the requirements for a low-level cargo drop. The C-17 is able to carry outsize and oversize cargo externally, up to including an M1 Abrams tank and two M1117 Armored Security Vehicles. The C-17 is the only aircraft capable of transporting the 155 mm (6.1 in) M1A2 Howitzer.
The cargo compartment is accessed through a large aft ramp that accommodates rolling stock, parked aircraft, and drive-through capability. The ramp allows vehicles to roll directly from the cargo compartment onto a truck or offload without having to be unloaded one piece at a time. This allows the aircraft to remain operational and effectively reduce turnaround time for fast-response, low-volume cargo/passenger movements. The C-17 also has a side ramp, which can be used to load and unload vehicles and equipment (or at airports equipped with fixed ladder, like in the case of Israel and Qatar) and a forward ramp allowing for drive-on/drive-off loading directly from ground level.
C17 Globemaster III delivery to Air force, Air Mobility Command, Air Force reserve command and its prototype YC-15 in formation over the Mojave desert.
Following the cancellation of the C-X program in September 1996, a demonstrator aircraft was built for technology development and risk reduction work in the form of the Boeing Model 767-200ER (which was later fitted with a General Electric YF120 turbofan engine demonstrator).
The C-17 made its maiden flight on 15 September 1991 from the McDonnell Douglas’s Long Beach, California plant. The program involved 30 aircraft: the original two YC-17s (74-1876 and 74–1877) for flight testing (although the second YC-17 was later repurposed as the Avionics Test Bed), and 28 production C-17As for the USAF. On 29 June 1995, the C-17A received initial operating capability (IOC).
The first aircraft (86–0127) was delivered to Charleston Air Force Base, South Carolina on 17 December 1993, while the final aircraft was delivered to Charleston Air Force base on 15 July 1995. The 437th Airlift Wing stationed at Charleston AFB is currently home to all active C-17 Globemasters assigned to the United States Air Force. Four additional units were originally planned for the Air Force Reserve Command (AFRC), but were later transferred to the Air Mobility Command (AMC).
The C-17 is expected to remain in service with USAF through 2040. The new C-17s received a multiyear procurement contract on 12 December 2006, for 79 aircraft of six different variants. On 23 January 2009, Boeing announced that it had received a $2.95 billion contract from the United States Air Force for six additional C-17s, bringing the total order to 85. This sixth batch of Globemasters includes 29 firm orders and 10 option orders, as well as 55 planned production changes out of which 41 are incorporated into all six new aircraft and 14 into four ones.
In July 2010, the Air Force announced plans to reduce its planned fleet of C-17s from 210 to 160 aircraft as a consequence of defense budget cuts. A Reuters article cited spare parts shortages and maintenance issues as the reason for the proposed reduction in fleet size; this is denied by Maj. Gen. Scott Vander Hamm, who claims that the fleet size will be reduced to allow more attention for “better execution of airlift, resupply and aeromedical evacuation missions across a wide spectrum of conflict”. Boeing maintains the C-17 production line at Long Beach Airport in California to build 10 aircraft per year. The first three sets are delivered as “composites”, i.e. without a payload and with a small crew of two or three. The first production model rolled out at Boeing’s Long Beach facility on 14 May 1991 and first flew on 15 September 1991.
The C-17 is a high-wing, four-engine, T-tailed military-transport aircraft. The C-17 commonly performs strategic airlift missions, transporting troops and cargo throughout the world; additional roles include tactical airlift, medical evacuation and airdrop missions. The C-17 can also perform rapid global mobility missions, transporting troops and large amounts of cargo to main operating bases or forward operating bases throughout the world. With a refueling boom, it can even provide airlift support to other aircraft with similar refueling capabilities. The C-17 carries the name of two previous piston engine-powered transports, the Douglas C-74 Globemaster and the Douglas C-124 Globemaster II. Boeing’s decision to base the new aircraft on its existing 767 airliner was intended to simplify design development and reduce the learning curve associated with creating a new airframe.
The C-17 is operated by a crew of three (pilot, copilot and loadmaster) from the rear cargo compartment. The cargo compartment is long, wide and high. There is also a lower cargo compartment with loading ramp at the rear of the aircraft. The cargo compartment is approximately wide and high. A large aft cargo door measuring on each side is fitted with a roller mechanism to ease the loading and unloading of cargo. In a regular rear load configuration, it can carry outsize cargo up to long. The aircraft is equipped with a global positioning system (GPS) and the Boeing-built Modular Mission Computer (BMMC) running JDISS (Joint Deployable Intelligence Support System).
The wing is swept back at 31.5 degrees and optimized for high-altitude airlift missions. It is swept back at 49.6 degrees in the operational flying pattern, which corresponds to a true chord of . Each wing features a swept leading edge and a straight trailing edge. The wing has a thin cross-section, allowing for maximum fuel capacity and unrestricted access to the cargo compartment. The wing structure has a total of 34 structural spars, 29 ribs and more than 150 panels.
The four engines are Pratt and Whitney F117-PW-100 turbofans, which are mounted under 35-degree swept wings. Each is directly driven by a shaft with no reduction gearing. The engine produces of thrust at maximum continuous power. No afterburner is required for high subsonic performance above . With the engines turning at over 5,000 rpm, the engines are just reaching their optimum speed for takeoff when the aircraft is at .
The C-17’s thrust-to-weight ratio gives it excellent acceleration performance, allowing it to take off from a 6,000 feet (1,830 m) runway and climb directly to its cruising altitude of 35,000 feet (11,000 m) in approximately 400 seconds, achieving a cruise speed of Mach 0.74 (). The landing gear is designed to withstand landings with a sink rate of per minute and side load factor of 2.3 times the aircraft’s weight.
C-17 Globemaster III Technical Specifications
The aircraft was designed to be highly flexible and adaptable. The cargo compartment is designed to be reconfigured for different aircraft missions with a rapid turnaround time. Boeing has developed pallet-based mission kits, which can quickly convert the C-17’s cargo compartment into an ambulance, troop transport or tanker configuration. The standard cargo floor can carry up to five mine-resistant ambush protected (MRAP) vehicles. The cargo compartment is wide by high and long, with rollers fitted to the floor. Side-facing seats are used to carry personnel on inter-theatre missions.
C-17 Globemaster III Customers
The C-17 has been ordered by the Royal Air Force, Royal Australian Air Force, United States Air Force, Republic of Singapore Air Force, Qatar Emiri Air Force, the Royal Saudi Air Force and NATO Heavy Airlift Wing. The Emirates SkyCargo fleet of four Boeing 777 freighters are fitted with an auxiliary fuel tank in the front cargo hold which allows some of these aircraft to also operate as tankers.
The first C-17 was delivered to the United States Air Force (USAF) on 15 January 1991. In total, 210 C-17s have been delivered to the USAF through 2012. The model was first used in combat during the US invasion of Afghanistan in 2001 and the Iraq War beginning 2003.
In addition, a number of aircraft were delivered to Australia for operation as part of its airlift force (Operation Falconer) in support of the war in Afghanistan. On 9 March 2007, the Australian Air Force took delivery of two Globemasters from No. 37 Squadron at RAAF Base Amberley to replace one C-130 Hercules and four Boeing 737 freighter aircraft (operated by No. 35 Squadron) that were retired in 2006.
These two aircraft were the first Globemasters in Australia’s airlift force.
The United Kingdom committed four C-17s to relief efforts following Typhoon Haiyan in the Philippines, transporting Royal Marines and equipment from Royal Navy Air Station Culdrose as part of Operation Gleaner.
In early 2015, US DoD announced that it would be sending two C-17s to the French Air Force for joint tactical air transport training under the “2015 Counter-Daesh campaign” in order to strengthen military cooperation between the countries.
Specifications (C-17A) and General characteristics (C-17 Globemaster III)
Maximum speed: Mach 0.72 (515 mph, 828 km/h) at 30,000 ft altitude
Cruise speed: Mach 0.69 (493 knots, 928 km/h) at 35,000 ft altitude
Range: Global with in-flight refueling
Takeoff distance: 6,000 ft (~1,829 m)
Landing distance: 4,500 ft (1,372 m).
Cargo capacity (internal): 37 pallets or equivalent
Maximum payload: 170,900 lb (77,519 kg)
Maximum takeoff weight: 585,000 lb (265.0 tons; 259,924 kg)
Range with max payload: 2,400 nmi (4,374 km).
Maximum fuel capacity: 52,410 US gal (193 m)
Usable fuel capacity: 48,220 US gal (178 m)
Oil capacity: 4,827 US gal (17 m).
Crew: Three (pilot, copilot and loadmaster)
Capacity: typical maximum; full combat; up to six F-15Es; two M1 Abrams tanks or three Stryker armored vehicles; or one UH-60 Black Hawk helicopter.
Strategic Airlift Capability program
The SAC program initiated by NATO is to improve strategic airlift capability of European nations with the C-17. The first C-17 was delivered to Europe on April 29, 2007. On February 1, 2010, the United Kingdom received its first C-17 under the SAC program. The aircraft will serve with No. 99 Squadron RAF based at RAF Brize Norton in Oxfordshire.
On 4 September 2012, India confirmed it had ordered 10 C-17s through a direct government-to-government deal. The Indian Air Force purchased ten C-17s through a government-to-government foreign military sale in September 2012 for a price of $4 billion, with the intention to start inducting them into service by June 2013. Boeing delivered 8 aircraft before India’s financial crisis forced the state to temporarily ground its fleet. The Indian Air Force (IAF) has grounded its fleet and all 10 C-17s within the fleet are idle.
On 12 October 2015, Boeing announced that India had placed an order for ten additional C-17s to be delivered by 2019.
The United States has sent an undisclosed number of C-17s to Qatar via the United Arab Emirates under a new deal for supply of ten aircraft, according to “Flight Global”. In December 2015, the U.S. announced plans to supply two C-17s to support French operations in Mali and provide airlift support for French forces in the Sahel. In April 2016, it was reported that two additional C-17s have been sent to France.
How many c17 does US and UK have ?
The U.S. Air Force has 210 C-17s in inventory as of March 2013, and the United Kingdom has 18.
Command at Travis AFB, Calif.; Dover AFB, Del.; Joint Base Lewis-McChord, Wash.; Joint Base Charleston, S.C., and Joint Base McGuire-Dix-Lakehurst, N.J. The Air National Guard flies C-17s from the 172d Airlift Wing, Jackson, Miss., and the 105th Airlift Wing, Stewart ANGB, N.Y. Additionally, Air Force Materiel Command operates two C-17s at Edwards AFB, Calif., and Pacific Air Forces operates aircraft at Joint Base Elmendorf-Richardson, Alaska, and Joint Base Pearl Harbor-Hickam, Hawaii. The Air Force Reserve Command operates aircraft at March Air Reserve Base, Calif., and Wright Patterson AFB, Ohio.
The aircraft can perform tactical airlift and airdrop missions and can transport litters and ambulatory patients during aeromedical evacuations 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 C-17 is operated by Air Mobility Command at Travis AFB, California; Dover AFB, Delaware; Joint Base Lewis-McChord, Washington; Joint Base Charleston, South Carolina, and Joint Base McGuire-Dix-Lakehurst, New Jersey.
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. 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. 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. Features 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. 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 can perform tactical airlift and airdrop missions and can transport litters and ambulatory patients during aeromedical evacuations 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.
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