The Aircraft

From Team Tuskegee pilot Steve Tupper's podcast episode about his initial training in the TG-7A . . .

The civilian designation is the Schweizer SGM 2-37.  It also has a military designation, and that’s the TG-7A.  

Schweizer made a grand total of 12 of them.  Six went to the US Air Force Academy.  In 2003, the academy transferred three of them to the Tuskegee Airmen Museum in Detroit and they’re now operated by the Tuskegee Airmen Glider Club.  Assuming that my check cleared, I’m a member of the club.  The club uses the aircraft to give orientation flights to kids from Detroit.  You don’t have to think too hard to understand how much an O-flight might end up meaning to a kid from deep in the D and it’s a really important mission.

The TG-7A is 27.5 feet long and a little over eight feet tall at the tail.  It has a 59.5-foot wingspan.

Max gross is 1,850 pounds.  It seats two side by side.  There’s a cargo area immediately behind the seats.  If you have room in your payload allotment, you can carry up to 100 pounds back there.  It consists of a large zippered bag suspended from the cross-bracing.  For as roomy as the cockpit is (or seems – the bubble canopy makes the cockpit appear really spacious), there’s no place to put anything other than in the bag in back.  If you carry anything outside of the bag and you drop it, it’s going to end up in the tail eventually.  There’s a pouch forward of the stick and behind your calves, but there’s not much room in that for much other than your checklists and maybe a backup radio.

I usually wear cargo shorts.  That usually means that I have a couple of lower pockets for spare glasses, my audio unit, and other stuff.  That doesn’t work in the TG-7A.  If you’re in the left seat, almost anything in your cargo pockets is going to obstruct the speed brake handle to your left or right.  If you have your logbook in your right cargo pocket, it’s going to obstruct your right forearm if you fly with your right hand, like you do when you land.  You can get away with having a couple of things in your right cargo pocket if you’re in the right seat.  But that’s about it.  If you want to carry a water bottle, as I do, it’s going to have to go in the bag.

When asked whether there are any drawbacks to the aircraft, I usually point out the lack of cup holders.  I know.  First-world problem.

The wings have a 17.9 aspect ratio.  The aircraft has a glide ratio of 29:1 and a minimum sink speed of 3.16 feet/sec.

It has a Lycoming O-235-L2C engine that develops 112 hp at 2,600 rpm at sea level and a 72-inch fixed prop.  I’m told that the aircraft is essentially a Piper Tomahawk firewall-forward.

The single fuel tank and associated system holds 14.2 gallons of usable fuel.  With proper leaning, at 2,500 pressure altitude, where I do a lot of my flying in the aircraft, the aircraft will do between 97 mph and 103 mph at 65% power (that’s about 2,300 rpm) and burn between five and six gallons per hour of 100LL avgas.  That’s near enough to what you’d expect for a C-152.  I actually plan to take the aircraft cross-country after I nail down the rating.  If you’ve ever thought about flying from, say, Detroit to Traverse City and back, low and slow and enjoying the scenery, a TG-7A would be a great choice.  And, if you’re going to fly low, you have much better glide performance in the TG-7A than you would in that C-152.

Controls include a single throttle, mix, and carb heat control in the center console and a stick and a speed brake control handle on each side.  I’ve flown it from each seat.  If you fly it from the left seat, your hands are bass-ackwards while you’re under power.  Left hand on the stick and right hand on the throttle.  When you pull the power to glide, you move your right hand to the stick and your left hand to the speed brake and things become a lot more intuitive.

You solo the aircraft from the right seat, presumably because you don’t have the hand-reversal thing.  The POH says to solo from the right seat as well.  That might also be because the fuel tank is in the left wing and it’s important to keep the lateral balance when soloing.  And Air Force doctrine requires that all aircraft with stick controls be flyable with the right hand on the stick and the left hand on the throttle.  But there’s nothing important that you can’t reach from the left seat.

The best elements of the aircraft are twofold.  First, it’s a taildragger.  Second, it’s that beautiful military yellow that you’ve seen on some Stearmans and Harvards.  And it has USAF insignia on the wings and the academy logo on the tail.  You can say that it’s not a proper warbird, but I’ve got your not-a-warbird thing right here and I’m lobbing it right into a cocked hat.  So there.

I don’t know much about gliders.  Other than my time in the TG-7A, my only time has been two aero-tows with Mark Grant in CAP’s Schweizer SGS 2-32 and another aerotow at Sandhill in a Schweizer SGS 2-33A.  My landing, thank you very much.

But the aerodynamic profile of the TG-7A seems a little weird to me.  Airspeed in the pattern and on landing is supposed to be 65 mph plus winds, with a minimum of 75 mph and a maximum of 85 mph.  Any bank or turn below 75 mph is prohibited.

The TG-7A stalls straight ahead in a pretty predictable and docile way.  But, apparently, any lack of coordination or any bank in a stall will cause the aircraft to depart controlled flight and it apparently takes a long time and a lot of altitude to recover.  I suspect that this is because there’s so much wing length to stall that, once you’re stalled, it takes a long time to reestablish that laminar flow over enough wing to give you controllable flight.

The POH says that the first and most prominent indication of the onset of a stall is the stall horn.  There’s supposedly some buffet and some oil-canning, but I gather from the POH that the aircraft flies like it’s not stalled until it’s stalled and that there aren’t a lot of audible or feelable warnings of stall onset other than the stall horn.

Stall speed at max gross on the model equipped with wing cuffs (which is what I’m flying) is 53 mph calibrated with wings level, 67 at 45 degrees of bank, and 75 at 60 degrees of bank.  If the speed brakes are out, those speeds are about three mph higher.

The glider club flies all low maneuvers at or above 80 mph.  They train all new guys to assume that they will die instantly if they bank the aircraft at less than 75 mph.  That’s an okay rule for me.  I’ll bet that you can get away with less than 75 mph.  I’ve been in a gaggle climb and seen airspeeds down to 65 mph with no ill effect.   But I have no problem whatsoever with keeping it at or above 80 when I’m in the pattern or in any attitude other than wings-level

The flight envelope extends out to +5.33G/-2.67G.  

Check out the Gallery page for lots of great images and videos of the TG-7A.