McDonnell Douglas YC-15 - Operational History

Operational History

Two YC-15s were built, one with a wingspan of 110 feet (#72-1876) and one with 132 feet (#72-1875). Both were 124 feet (38 m) long and powered by four Pratt & Whitney JT8D-17 engines, each with 15,500 lbf (68.9 kN) of thrust.

The first flight was 26 August 1975. The second prototype followed in December. They were tested for some time at McDonnell Douglas as the Boeing entry was not ready until almost a year later. In November 1976 both designs were transferred to Edwards Air Force Base for head-to-head testing, including lifting heavy loads like tanks and artillery from dirt airfields at Graham Ranch, off the end of Runway 22.

In Phase II of the flight test program, a "refanned" Pratt & Whitney JT8D-209 was tested in #1 nacelle of 72-1876 and a CFM International CFM56 was tested in the #1 nacelle of 72-1875. In addition, a new wing with increased chord and span was flown on 72-1875.

The YC-15s completed a 600 hour flight test program in 1977. By this point the seeds of the AMST program's demise had already been sown. In March 1976 the Air Force Chief of Staff Gen. David C. Jones asked the Air Force Systems Command to see if it was possible to use a single model of the AMST for both strategic and tactical airlift roles, or alternatively, if it was possible to develop non-STOL derivatives of the AMST for the strategic airlift role. This led to a series of studies which basically stated that such a modification was not easy, and would require major changes to either design to produce a much larger aircraft.

Both the YC-14 and YC-15 met or exceeded the AMST specifications under most conditions. However, the increasing importance of the strategic vs. tactical mission eventually led an end of AMST program in December 1979. Then in November 1979, the C-X Task Force formed to develop the required strategic aircraft with tactical capability. The C-X program selected a proposal for an enlarged and upgraded YC-15 that was later developed into C-17 Globemaster III. The Lockheed C-130 Hercules would be further improved and remains in service as of 2011.

After the flight test program, the two aircraft were stored at the AMARC, located at Davis-Monthan Air Force Base. 72-1875 was subsequently moved to the nearby Pima Air & Space Museum in 1981. This aircraft (72-1875) was returned to flying status by McDonnell Douglas in 1996 and was first reflown on 11 April 1997. The aircraft was ferried to Long Beach, California on 16 April 1997, to support the C-17 program. On 11 July 1998 the aircraft suffered a massive failure of the #1 engine during flight and made an emergency landing at Palmdale, California. Upon inspection, the aircraft was deemed too expensive to repair and was stored at Palmdale. In 2008 it was later moved by road to Edwards AFB, where it is now on display at the Air Force Flight Test Center Museum's "Century Circle" display area, just outside the base's west gate. Sadly, the other YC-15 (72-1876), which had remained on Celebrity Row at the AMARG for many years, was destroyed in place in April 2012. It was within easy towing distance of the Pima Air Museum, which had hosted its sister for almost fifteen years, but no efforts were made to transfer the aircraft there instead of destroying it.