The Boeing C-17 Globemaster III military airlift aircraft is a high-wing, four-engine, T-tailed military transport vehicle capable of carrying payloads up to 77 tonnes (t). The aircraft has an international range and the ability to land on small airfields with unmatched airlift capability.
The C-17 aircraft was first delivered to the US Air Force (USAF) in 1993 and entered service in January 1995.
Currently, there are 275 aircraft in the global C-17 fleet serving the USAF and the allied nations, including the UK, Canada, Australia, India, Kuwait, Qatar, the United Arab Emirates and the 12-nation Strategic Airlift Capability.
Boeing, in partnership with Mahindra Defence Systems, opened a C-17 training centre in 2016 to serve the Indian Air Force (IAF). The company also signed an $8m contract to train C-17 aircrews at its international training centre (ITC) in the UK under the Nato’s Strategic Airlift Capability (SAC) programme. It also trains Emirati C-17 students.
The final Boeing Globemaster III military aircraft left the company’s production facility in Long Beach, California, US, in November 2015, marking the official end of the aircraft’s production.
In September 2021, the US Department of Defense awarded a follow-on contract worth up to $23.8bn to Boeing for ten years for the sustainment of the C-17 fleet. The contract is part of a performance-based logistics agreement to continue the critical sustainment activities of the fleet. Currently, the programme has financial backing until September 2024, supported by a Phase I grant amounting to $3.5m. Boeing supports the C-17 fleet together with its eight global partners.
C-17 design and features
The aircraft is 53m long and 16.8m high with a wingspan of 51.75m. A propulsive lift system, which uses engine exhaust to generate lift, allows the C-17 to achieve safe landings on short runways. The C-17 is capable of landing a full payload in less than 3,000ft.
The C-17 Globemaster III aircraft is capable of turning in a small radius and can complete a 180-degree star turn in 80ft. It can also carry out routine backing. A fully loaded aircraft is capable of backing up a 2% gradient slope using the directed flow thrust reversers.
Cockpit of the C-17 Globemaster III
C-17’s cockpit features a fully integrated electronic cockpit, which has pilot, co-pilot, and two observer positions. The digital avionics system has four Honeywell multifunction cathode-ray tube displays, two full-capability HUDs, plus cargo systems.
The quadruple-redundant electronic flight control system also has a mechanically actuated backup system.
There are two Lockheed Martin central processing computers, one Hamilton Sundstrand data management computer, and two Honeywell air data computers.
A programme to upgrade the C-17A avionics includes new mission computers and displays, and new software for the warning and caution system, provided by Northrop Grumman Navigation Systems.
The automatic flight control system is upgraded with BAE Systems’ CsLEOS real-time operating system, which is certified for global air traffic management system requirements.
Cargo systems on Boeing’s C-17 Globemaster III
The advanced cargo system allows the operation of all systems on any type of mission.
The design of the cargo compartment allows the C-17 to carry a wide range of vehicles, palleted cargo, paratroopers, airdrop loads, and aeromedical evacuees.
The cargo compartment has a sufficiently large cross-section to transport large wheeled and tracked vehicles, tanks, helicopters (such as the AH-64 Apache), artillery, and weapons such as the Patriot missile system.
Three Bradley armoured vehicles comprise one deployment load on the C-17. The US Army M1A1 main battle tank can be carried with other vehicles. The cargo bay can accommodate loads ranging from an Abrams tank, four Bushmaster vehicles, and three black hawk helicopters.
The maximum payload is 170,900lb with 18 pallet positions, including four on the ramp. Airdrop capabilities include a single load of up to 60,000lb, and sequential loads of up to 110,000lb, container delivery system airdrop up to 40 containers, 2,350lb, each up to 102 paratroops.
The transport aircraft is equipped for low-altitude parachute extraction system drops. For Medevac, the C-17 can transport up to 36 litter and 54 ambulatory patients and attendants. C-17s can take off from a 7,600ft airfield, fly 2,400nm, and refuel while in flight. It can land on a 3,500ft-long and 90ft-wide airstrip.
The aircraft has the capacity to carry 134 passengers, 102 paratroopers, six high-dependency medical patients or 36 stretcher patients, one CH-47F Chinook helicopter, 18 463l military pallets, and about 77t of cargo.
Countermeasure technology of C-17 Globemaster III
AN/AAR-47 has a suite of surface-mounted thermal sensors around the aircraft, which detect the thermal signature of the missile exhaust plume. Frequency selection and signal processing techniques are used to minimise the false alarm rate.
The system provides a warning to the crew via the cockpit indicator unit of the presence and direction of the missile threat. A signal is automatically sent to the ALE-47 dispenser.
The AN/ALE-47 is capable of carrying a mix of expendable countermeasures, including jammers. The system interfaces to the C-17 Globemaster III aircraft’s sensors. The aircrew can select the mode of operation of the dispenser for fully automatic, semi-automatic, or manual operation.
The cockpit control unit can be used to input mission data, together with the numbers and types of expendable countermeasures systems loaded into the ALE-47. The cockpit controller updates and displays the status of the dispenser and the numbers and types of countermeasures remaining.
ALE-47 is capable of dispensing the new-generation active expendable decoys, POET and GEN-X, in addition to the conventional chaff and flare decoys that are compatible with the previous-generation ALE-40 and ALE-39 dispensers.
A total of 56 USAF C-17 aircraft are equipped with the Northrop Grumman large aircraft infra-red countermeasures (LAIRCM) system.
LAIRCM is based on the AN/AAQ-24(V) Nemesis. It entered low-rate initial production in August 2002 and completed its initial operational test and evaluation in July 2004. A total of 25 upgraded aircraft have been delivered. The system entered service in 2007. The four aircraft leased by the UK Royal Air Force are fitted with LAIRCM.
Engine and performance
The aircraft is powered by four Pratt & Whitney PW2040 (military designation-F117-PW-100) turbofan engines with 40,440lb thrust, each integrated into the wings. Engine thrust reversers, which are operable in flight, and speed brakes enable the aircraft to carry out rapid deceleration and descent manoeuvres.
The engine exhaust is directed onto large flaps, which extend into the exhaust stream, allowing the aircraft to fly a steep approach at a relatively low landing speed.
The cruise speed is between Mach 0.74 and 0.77. The range without in-flight refuelling, and with a payload of 160,000lb, is 2,400nm. Aerial refuelling provides an intercontinental non-stop range. It can reach an altitude of 45,000ft and travel a range of 10,390km with paratroopers.
C-17 Globemaster orders and deliveries
In February 2009, a $2.95bn contract was awarded to Boeing to deliver 15 additional C-17s for the USAF. Two C-17s were delivered to the Stewart Air National Guard Base in July 2011.
In August 2006, a fifth aircraft (delivered in April 2008) was ordered and the purchase of the first four aircraft in 2008 was confirmed. In December 2007, the UK purchased a sixth aircraft, which was delivered in June 2008. Boeing delivered the seventh aircraft in November 2010. The eighth aircraft was delivered to the UK RAF in May 2012.
Boeing trains RAF C-17 aircrew and engineers at the C-17 International Training Centre (ITC) in Farnborough, UK, on interactive, high-fidelity simulators under a new Synthetic Training Service (STS) contract through 2040 signed in May 2021.
In March 2006, Australia selected the C-17, with a requirement for four aircraft. The first aircraft was delivered in December 2006, the second in May 2007, the third in February 2008, and the final aircraft in March 2008.
Australia signed a foreign military sale (FMS) agreement with the US government in April 2011 to procure the fifth C-17 for the Royal Australian Air Force. It was delivered in September 2011. An order for the sixth C-17 was placed in 2011 and the same was delivered in November 2012. Australia ordered two more aircraft in April 2015 and took delivery of the seventh in July 2015 and the eighth aircraft in November 2015.
In July 2006, Canada announced the selection of the C-17 with a requirement for four aircraft. The contract was signed in February 2007. Deliveries began in August 2007 and concluded in April 2008. An additional C-17, ordered by Canada in 2014, was delivered in March 2015.
In September 2006, Nato announced its intention to buy an initial three or four C-17 aircraft. In June 2007, an international consortium, consisting of 15 Nato countries plus two partner countries (Finland and Sweden), agreed to set up the strategic airlift capability (SAC) at Papa Air Base in Hungary.
The Nato Airlift Management Organisation purchases, owns, and manages the aircraft. A multinational military unit, the heavy airlift wing, conducts airlift operations.
In May 2008, SAC requested the foreign military sale of the first two C-17 aircraft. The first C-17 was delivered to the SAC in July 2009. The second and third C-17s were delivered in September 2009 and October 2009 respectively. The SAC1 C-17’s first flight was completed in June 2009.
In March 2007, Boeing announced C-17 production would conclude in 2009, when current orders have been fulfilled. However, the purchase of 15 additional aircraft for the USAF was approved in 2008.
In July 2008, Qatar placed an order for two C-17s with an option for an additional two units. The first aircraft was delivered in August 2009, and the second in September 2009. Qatar received the third and fourth aircraft in 2012. An order for four more aircraft was placed in June 2015.
The UAE announced in February 2009 that it would acquire four C-17s. The Emirates ordered a total of six C-17s in January 2010. The first C-17 was delivered to the UAE in May 2011 and the second in June 2011. The third C-17 was delivered in July 2011. The last aircraft was delivered in June 2012.
The Indian Ministry of Defence signed a $4.1bn agreement with Boeing in June 2011 to acquire ten C-17 airlifters. US Congress authorised the FMS in May 2010. The C-17 met all the IAF’s requirements during rigorous field evaluation trials held in India in June 2010. Boeing delivered the first C-17 to the IAF in June 2013 and four more by November 2013. The remaining five were delivered in 2014. The country received the 11th delivery in 2019.
Kuwait received two C-17s in 2014. The sale also included related equipment and training support.
Flight testing of the C-17 using a blend of synthetic fuel and JP-8 began in October 2007, as part of a USAF process to develop more efficient fuel for its fleet, with less reliance on imported petrol. Certification for the aircraft powered by synthetic fuel was completed in February 2008.
Boeing received an $18.7m contract to provide logistics support and training simulator maintenance for the UAE’s C-17 aircraft for two years, in 2017.