Pilot estimates for performance limits.

schwenn · Post by **schwenn** » Mon Sep 22, 2008 19:11

Dear Aeronca Pilots,

I am interested in a pre-war (1949) Chief.

There's a plate on the plane which gives the VNE (I believe it indicated 119 or 124knots). But what I'm really interested in are the experiences of (pre-war) Aeronca pilots with excess speed (feel, damage, controllability). For example in an unintended (or otherwise) dive.

What do these pilots believe should be the VNE in no (or very light) turbulence. To put it a different way (assuming no limit on power) what maximum speed would the airplane be comfortable with (no significant damage) in the long term?

Thank you,

Peter Schwenn

Post by **joea** » Mon Sep 22, 2008 20:51

Peter,

Welcome to the group.

I have flown a few pre-war Aeronca's and they are different from the post-war versions in that they had a more critical wing. The earlier airplanes fly just a bit faster, but are as well not as docile as their post war brothers on stalls and such.

That said, my gut feeling is that the pre-war versions, if in good condition, would have a bit higher VNE than the later models. This is without looking at the type certificate data sheet, which will have the real information on their limiits.

Joe A

(BTW, assume that you meant 1939 on your post above?)

schwenn · Post by **schwenn** » Mon Sep 22, 2008 21:10

Joe A,

Certificate VNE's are estimates by the manufacturer and are not checked nor required to be checked by the FAA or anyone else. The manufacturer for example may set it low to avoid litigation or satisfy a certification requirement such as LSA; or it may be set high to suggest performance higher than a competitor's. Or they may simply be a guess, or in error. Or they may be artificially distinguishing between different models that are in fact structurally and aerodynamically identical. They may even be good faith, empirically establlished, reliable estimates

That's the reason for my question: what do Aeronca pilots judge to be the reasonable limit (again, assuming unlimited power) for continuous operation in no (or low) turbulence of the airplane in question.

Peter

Roger Anderson · Post by **Roger Anderson** » Mon Sep 22, 2008 21:23

I owned a '39 Chief and have a '46 now. I can't remember the VNE on the '39, 129 being VNE on the '46 (is that right?). These planes are pretty much high lift, but high drag machines. I don't believe that normal flight would accidently ever approach VNE. I use to loop my 7DC which also had a 129 VNE. As I recall, I had to point it way down to get the speed any where close to VNE. I think the manufacture's speeds were probably pretty reasonable, and exceeding them somewhat difficult, other than an intentional steep dive.

Post by **joea** » Mon Sep 22, 2008 21:31

On current airplanes you may be correct but these airplanes are not current. They were designed and built in the 1930's and 1940's. We did not have the situation that we have now with lawyers suing everyone in sight after an accident, nor companies making decisions on the airplanes to ward off being sued. They did what they could to sell airplanes and for a long time it worked.

Personally I would not take any of these airplanes near VNE on a regular basis, and I am a former test pilot. Have flown for Boeing, McDonnell Douglas and Bombardier and seen and done things that are not normal for the everyday pilot. These old birds are 70 years old (or older) and if someone wants to take theirs to the outer limits of the certificate, I will watch (and say a prayer for them) on the ground.

I have flown Aeronca's on and off for over 30 years and trust them with my life all the time. That said, I am not going to push their outer limits with their being this age. In answer to your question, I feel that staying within the posted limits of the TCDS most Aeronca owners and pilots will be safe.

Joe A

Captgrumps · Post by **Captgrumps** » Tue Sep 23, 2008 00:48

The level cruise maximum for 50C/65C/65CA is 100 mph. The glide or dive speed (VNE as you call it) is 135 mph. It is in the FAA aircraft Specs.
Back in 1953 I spun my 65C, got it really nose down and exceeded the dive speed--It does like to point its nose down after a turn or two--the airspeed went off the high side original guage and broke it. The old flimsy original windshield protruded in but didn't break. The 1940 airplane was 13 years old then, I was young, indestuctable, stupid and decided not to do it again. Now 55 years later spins for fun don't turn me on and I do my best to avoid spins not for fun..

Doug

jc pacquin · Post by **jc pacquin** » Sun Nov 30, 2008 21:46

Joe and Grumps have it right! High speed in a champ or chief is not reccomended When you near the limit in an old champ or chief you become in effect a "test pilot". These old crates were built for a 10-12 year expectation. I go up to "cool it", look around, amaze myself that I'm able to fly at all and at 85mph am king of all I survey. My favorite is landing, pushing the stick all the way over, full opp. rudder and coming down to 10 feet, then flicking it straight and, just nose high, trying to grease it. FUN! In the Mooney super 21, younger, it was another story, FULL BORE but it was 4 years old and I had Chuck Yeager tendencies.jp

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