Main Page | See live article | Alphabetical index

C-17 Globemaster

The C-17 Globemaster is a transport plane manufactured by Boeing, used by the United States Air Force and the Royal Air Force.



Table of contents
1 Mission
2 Features
3 Background
4 General characteristics
5 Wartime Usage

Mission

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.

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 rates of 74.7 and 82.5 percent, respectively. The Boeing warranty assures these figures will be met.

The C-17 measures 174 feet long (53 meters) with a wingspan of 169 feet, 10 inches (51.75 meters). 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 pounds 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 pounds (77,519 kilograms), and its maximum gross takeoff weight is 585,000 pounds (265,352 kilograms). With a payload of 160,000 pounds (72,575 kilograms) and an initial cruise altitude of 28,000 feet (8,534 meters), , the C-17 has an unrefueled range of approximately 2,400 nautical miles. Its cruise speed is approximately 450 knots (.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 feet (914 meters) and only 90 feet wide (27.4 meters). Even on such narrow runways, the C-17 can turn around using a three-point star turn and its backing capability.

Background

The C-17 was designed and created by what was McDonnell-Douglas (the company and project was taken over by Boeing later in the decade.) Its maiden flight was on September 15, 1991 from the McDonnell-Douglas west coast plant in Long Beach, California. The first production model was delivered to Charleston Air Force Base, S.C., June 14, 1993. The first squadron of C-17s, the 17th Airlift Squadron, was declared operationally ready January 17, 1995. The Air Force originally programmed to buy a total of 120 C-17s, with the last one being delivered in November 2004. The fiscal 2000 budget funded another 14 C-17s for special operations duty. Basing of the original 120 C-17s will be at Charleston AFB; McChord AFB, Washington (first aircraft arrived in July 1999); Altus AFB, Oklahoma; and at an Air National Guard unit in Jackson, Miss. Basing of the additional 14 aircraft has not been determined.

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.; in the RAF the C-17 is operated by No. 99 Squadron.

General characteristics

Primary Function: Cargo and troop transport
Prime Contractor: Boeing Company
Power Plant: Four Pratt and Whitney F117-PW-100 turbofan engines
Thrust: 40,440 pounds, each engine
Wingspan: 169 feet 10 inches (to winglet tips) (51.75 meters)
Length: 174 feet (53 meters)
Height: 55 feet 1 inch (16.79 meters)
Cargo Compartment: length, 88 feet (26.82 meters); width, 18 feet (5.48 meters); height, 12 feet 4 inches (3.76 meters)
Speed: 450 knots at 28,000 feet (8,534 meters) (Mach .74)
Service Ceiling: 45,000 feet at cruising speed (13,716 meters)
Range: Global with in-flight refueling
Crew: Three (two pilots and one loadmaster)
Maximum Peacetime Takeoff Weight: 585,000 pounds (265,352 kilograms)
Load: 102 troops/paratroops; 36 litter and 54 ambulatory patients and attendants; 170,900 pounds (77,519 kilograms) of cargo (18 pallet positions)
Unit Cost: $236.7 million (FY98 constant dollars)
Date Deployed: June 1993
Inventory: Active duty, 58; Air National Guard, 6; Air Force Reserve, 0

Wartime Usage

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.