That capability has become more important as U.S. mechanized equipment has grown larger and heavier in response to improving adversary capabilities. The Air Force said those changes have increased demand for aircraft able to move large and outsize cargo during armed contingencies, peacekeeping deployments and humanitarian missions.
The Boeing-built aircraft can rapidly transport troops and equipment to major operating bases or directly to forward locations. It can also conduct tactical airlift, airdrop and aeromedical evacuation missions, giving commanders several transport options through a single platform.
A large rear ramp and door system accommodates almost all of the Army’s air-transportable equipment, including a 69-ton M1 Abrams, armored vehicles, trucks and trailers. The cargo floor can be converted between a flat surface for vehicles and a rollerized configuration carrying as many as 18 pallets.
The C-17 can transport 102 troops or paratroopers with their equipment and has a maximum takeoff weight of 585,000 pounds. It can also carry 36 litter patients and 54 ambulatory patients with attendants during aeromedical evacuation missions.
Its high-lift wing, slats and externally blown flaps allow operations from small and austere airfields. The aircraft can take off and land on a runway measuring 3,500 feet long and 90 feet wide, then turn using a three-point star maneuver and its ability to move in reverse.
With a payload of 164,900 pounds, the C-17 has an unrefueled range of about 2,400 nautical miles from an initial cruise altitude of 28,000 feet. The aircraft cruises at approximately 450 knots and can achieve global range through in-flight refueling.
Four Pratt & Whitney F117-PW-100 turbofan engines power the aircraft, with each producing 40,440 pounds of thrust. Their thrust reversers reduce the ingestion of dust and debris, allow backward taxiing and generate drag during rapid descents.
The aircraft requires a crew of two pilots and one loadmaster, limiting manpower needs and long-term operating costs. A basic aeromedical evacuation crew adds two flight nurses and three medical technicians, although staffing can be adjusted to patients’ needs.
Air Force requirements call for a 92% probability of mission completion and no more than 20 maintenance man-hours for each flying hour. Full and partial mission-availability targets are 74.7% and 82.5%, respectively, with Boeing’s warranty assuring that those figures will be met.
