First aerial refuelling with a KC-10 and the prototype C-17 was made on September 23, 1992. Trials with a Boeing KC-135 tanker were also flown but the C-17's sensitivity in roll, pitch and yaw while behind the Stratotanker required some modification to the software in the flight control system.

Close-up on prototype McDonnell Douglas C-17A 87-0025 during an air-to-air refuelling sortie.

Piloted by McDonnell Douglas test pilot Bill Casey with Lt Col George London of the USAF as co-pilot, C-17 87-0025 lifts off from Long Beach Airport on its first flight. The date was September 15, 1991, and the aircraft successfully completed a two hour 24 minute flight before touching down at Edwards Air Force Base to to begin its flight test programme.

Final assembly of the C-17 in Building 54 at Long Beach with the third production aircraft fully painted behind the fourth or P-4. The structure of the aircraft comprises 78% aluminium, 11% steel, 6% titanium and 5% composites, as measured by weight.

Power plant of the C-17 is the Pratt & Whitney F117 high bypass turbofan which, apart from the thrust reverser assembly, is almost identical to the PW2040 commercial version used on the Boeing 757. On the edges of the intake are vortex generators which are intended to delay the onset of flow separation on the wings.

Aircraft P-4 undergoing pre-first flight check-out at Long Beach. Initial operational capability with the Air Force is expected in late-1994.

The winged horse marking of the USAF's Operational Test and Evaluation Center on the nose of P-4 (89-1190), the fifth C-17 to fly and the first without the extensive test instrumentation carried by the other aircraft in the trials programme.

In Air Mobility Command service, the C-17 Globemaster III will carry the latest all-grey colour scheme and low-visibility markings as shown here on P-1 88-0265, pictured during its first flight on May 18, 1992.

Tufted to record airflow patterns, the first production C-17 88-0265 underwent loading trials in late-1992 with an M60 main battle tank and later flew with the vehicle inside the cargo hold.

Pilot and co-pilot together with a single loadmaster form the basic crew of a C-17. The cockpit is large and roomy as shown here on a simulator with the instrument panel dominated by head-up displays (the first on a transport aircraft) and CRTs providing a range of information. Fighter-like control sticks are another unique feature.

McDonnell Douglas C-17 Globemaster III

Diagram showing the externally blown flaps and the exhaust path through the rear surfaces.

General arrangement drawing of the McDonnell Douglas C-17 Globemaster III strategic transport.

Predecessors of the new Globemaster III were the initial Douglas C-74 of which 14 were built. CN-402 or 42-65402 was the prototype which was delivered on October 11, 1945.

This C-124C Globemaster II was one of 243 produced and followed the first YC-124 which flew on November 27, 1949, and 204 C-124As.

The McDonnell Douglas YC-15 Stol transport prototype contributed significantly towards design of the C-17. Powered by four JT8D turbofans, the first of two prototype YC-15s made its initial flight on August 26, 1975, and was built as a contender for the USAF's advanced medium short take-off and landing transport programme (AMST) to replace the C-130 Hercules. No order was placed and the YC-15 was subsequently grounded.