USAF Academy TG-7A Motorglider

© 1998-2010 by Brian Mork


The TG-7A airplane is one of those rare birds you just won't see many places in the world. Rumor says it's flown only at the United States Air Force Academy and maybe on a few special CIA missions. It was made on special order from Schweitzer to perform similar to a 2-33, ...but with an engine: fifty-nine and a half feet of wing, and a 112 HP Lycoming O-235 up front.

The combination has a few quirks. I don't know of any other plane where you recover from inverted, stall/spin situations by yanking back on the stick. Specifically, in these situations, "..it is more expeditious to pull straight through to the horizon (Split S [or slice-back]) than to roll to a wings level upright attitude." Flight experience shows this to be true. Those long wings take a long time to roll wings level!

I had the chance to fly the TG-7 while stationed at the Air Force Academy, and while most of the flights were student instructional sorties, I had a chance to investigate a few fun airports tucked into the crevices of the Rocky Mountains. The pictures below are from a drop-in at Leadville, Colorado, the highest airport in the Continental United States (CONUS).

3/4 Tailview with MountainsTwo Pilots at Leadville

Downwind for landing at Leadville, Colorado is flown over 10,000' MSL. Click on the picture to get the fullsize image of the two above pictures. Both were taken before the days of digital cameras; they're scanned in color photos.

The 94th Flight Training Squadron maintains their own web page with more mission information. In December 2004, Soaring magazine published an article I wrote about the TG-7.

prop-stop-glidingThe picture here shows a prop-stopped glide. If you click on the picture, a .mov video will attempt to play on your computer. On the video, notice 3 instruments are visible across the instrument panel - Engine RPM, Airspeed, and Altimeter. Video is how much of the testing documentation was done back in the 1950s and 60s, so enjoy this short 5 MB video snippet. The video starts about 7800 MSL, 0 RPM and accelerating through 70 MPH at about 2 MPH / second. The propellor flips through a piston top-dead-center at about 90 MPH and then stalls against compression until about 108 MPH. Reaching 110 MPH, the prop turns over and immediately catches with a fast rise in engine RPM. Altitude continues down to about 7000 MSL until the aircraft levels off with the engine running. Airspeed within 10 MPH of yellow arc limit is required to get the propeller turning.


 
This page is maintained by Brian Mork. It was last modified March 2010. Suggestions for changes and comments are always welcome. Contact me via e-mail.