Yale vs. T-6/SNJ performance question

Enemy Ace · **Posted:** Mon Dec 28, 2009 5:23 pm

Just saw another Yale for sale on Ebay today, it seems like those things are falling out of the trees. I really don't know all that much about the yale other than it appears to be a fixed gear T-6 with a smaller engine (R985?). Could some of you experts please enlighten us about the performance difference? Obviously the 6 will be faster but by how much? cruise speeds? fuel burns? reliability and resale value? Inquiring minds want to know!

EDowning · **Posted:** Mon Dec 28, 2009 5:54 pm

The NA-64 Yale and the T-6 have very little in common other than they are both North American products. The Yale has 440hp and is power by a Wright 975-E3 vs the T-6 with a 600hp Pratt 1340. The Yale doesn't have a hydraulic system other than traditional bakes. Different wing, gear is 2 feet narrower and CG is about a foot higher. Free castering tailwheel on the Yale, although many are modified.

T-6 is rather docile and very forgiving vs the Yale, which has some rather aggressive stall characteristics and is much more touchy to land. Both aircraft have a 24v electrical system. Yale has great cockpit heat due to its exhaust pipe heating system.

Yales typically don't sell for that much relative to T-6s and are poor candidates for restoration because of the fact that they are comparable to the T-6 in restoration cost.

All of that said, the Yale is a pleasure to fly from a handling standpoint in the air, and all of the mentioned flight challenges can be managed with proper attention the the flight envelope.

The commonality of the T-6 coupled with the fact that T-6 time is a common requirement to fly other piston powered tailwheel warbirds makes it the best choice of the two.

warbird_patrick · **Posted:** Mon Dec 28, 2009 6:04 pm

The NA-64 is built up with a lot of parts from the BT-9, BT-14, and Harvard. If you look at the parts catalog for the NA-64 you would see that it has parts from almost every trainer North American made. As long as you don't go under 80 knots with full flaps you are in good shape, they are great flying aircraft. A good book to get is "HARVARD! The North American Trainers in Canada" has a lot of information in there on the Yale. Also if you go in the Maintenance hanger, you well see the thread on the restoration of my Yale 3383.

Patrick

warbird_patrick · **Posted:** Mon Dec 28, 2009 6:17 pm

Also here is the general data out of the Operating instructions:

Overall Span: 40 ft. 1 7/16"
Overall Length 28 ft. 4 5/16"
Airfoil Section:
Root NACA2215
Tip NACA2209
Wheel Tread: 7 ft. 11"
Normal Gross Weight: 4291 Lbs.
Weight Empty: 3163 Lbs.

Maximum Speed at Alt: 170.2 Mph
Maximum Rate of climb: 1120' Fpm

Enemy Ace · **Posted:** Mon Dec 28, 2009 6:27 pm

Interesting. I take it then that yale time does not count as "T-6 time" for flying other stuff up the food chain? Although 170 MPH is faster than I expected.
Patrick are you going to go with a 975 or upgrade to a 985? is there much of a difference that makes it worth doing?

warbird_patrick · **Posted:** Mon Dec 28, 2009 6:46 pm

Enemy Ace wrote:

Interesting. I take it then that yale time does not count as "T-6 time" for flying other stuff up the food chain? Although 170 MPH is faster than I expected.
Patrick are you going to go with a 975 or upgrade to a 985? is there much of a difference that makes it worth doing?

I am restoring 3383 with all original equipment with the R-975-E3 and to the wireless trainer. I have been told it is the most complete wireless trainer that survived as it was un-touched since 1946 and still has all of the wireless operators gear still installed minus the R1155 and R1154. It also has all of the original factory grease pencil markings through out the airframe.

I think the major reason between the R-975 and R-985 is reliability. The 985 is a more favorable engine then the 975. The 985 was installed on the Army Aircorps BT-14's

EDowning · **Posted:** Mon Dec 28, 2009 7:09 pm

The only way you will see 170mph is in a dive. Normal cruise will be about 135 at 28 and 1850. And 1100 fpm would be the rate of climb you would see if you were climbing over a flight of pegasus unicorns.

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Yale vs. T-6/SNJ performance question

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