McDonnell Douglas YC-15 Vs Boeing YC-14
A tactical transport aircraft with four engines designed for short takeoff and landing (STOL) was the McDonnell Douglas (now Boeing) YC-15. It was McDonnell Douglas’ entry in the competition for the Advanced Medium STOL Transport (AMST), which was held to replace the USAF’s main STOL tactical transport, the Lockheed C-130 Hercules. A pair of YC-15s were constructed, including a 110-foot (S/N 72-1876) and a 132-foot (S/N 72-1875) wingspan.
When it made its maiden flight in 1976, the Boeing YC-14 represented a significant aviation milestone. This aircraft represented numerous firsts in aircraft design, prominent among them being the use of boundary-layer control in conjunction with upper-surface blowing, which caused the jet engine flow to turn downward and enabled flight at low airspeeds.
However, neither the YC-15 nor the YC-14 were put into production, even though the successful C-17 Globemaster III was built using the YC-15’s basic design.
AMST program termination
Ron Wagner, former USAF pilot in the Presidential Wing at Andrews AFB, recalls on Quora;
‘I flew one of the prototypes of the AMST, which was intended to produce a replacement for the C-130. The AMST proposal was issued on November 10, 1972. Boeing responded with the YC-14.
‘I was familiar with the YC-15 response from McDonnel-Douglas, which first flew on August 26, 1975. A second prototype flew in December 1975. The second one had a longer wingspan and was painted in camouflage colors.
‘The program ended in December 1979. […] I got to fly the cool-looking camouflaged YC-15 when it was at Andrews Air Force Base sometime in late 1978/early 1979. I left Andrews in January 1980, which was AFTER the AMST program ended.
‘McDonnell Douglas took the second prototype to Andrews to impress Pentagon generals and members of Congress in a final push for a contract. It failed to get any orders.’
McDonnell Douglas YC-15 flight
He continues;
‘I flew it only locally around Andrews, making the takeoff and flying around the area for a bit. It used a DC-10 cockpit but had the ankle-height windows you see in the C-130. That was the best view I ever got of my home, local flying area. Cool view. The test pilot let me set up the approach, but being one of only two in the world, he took the landing himself.
‘I later saw and photographed the first prototype at “the Boneyard” in Arizona. But they eventually scrapped it.
‘This is the one I flew. Note the cool lower windows.
‘That must have been interesting to have been involved in upgrading the YC-15 to the C-17. The only 4-engine time I have in my 10,000+ hours is the 15 minutes I flew the YC-15. It handled like a small plane, really fun to fly.
The C-130 Endures
‘Now, more than 51 years after the AMST proposal was issued and 44 years after that project was canceled, Lockheed is still delivering new C-130s.’
Wagner concludes;
‘Think of this bizarre fact: When the C-130 was 18 years old, the USAF issued a proposal to replace it, which actually sounds about right for the timing. But they didn’t buy it and the C-130 will be 70 years old in August of this year and new ones are still on backorder.’
Photo by U.S. Air Force and Mike Freer via Wikipedia