Trim

Post-War Aeronca Champ airplanes
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Capair
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Trim

Post by Capair »

I have a question for the Aeronca guru's. I was out flying and was practicing stalls and engine out procedures. The book calls for 60 as best glide. I cannot trim for 60. I run out of trim. I have the trim all the way nose up when I am alone on landing and still have to hold back pressure. Is there anyone who has any thoughts can I adjust the trim tab. I ran it full aft and it doesn't look like I can adjust it much.

MikeB
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Re: Trim

Post by MikeB »

I don't know for sure but I think that's 'typical' for Aeroncas or at least on the Champs. Every one I've flown has been like that. Possibly to compensate once a back seat passenger is in place. I know it gets better with someone in the back. There is some further adjustment on the trim tab that would help but I've never tried to change it beyond the correct specs. There is some variation between models.

MikeB

WWhunter
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Re: Trim

Post by WWhunter »

I agree with Mike. When I first bought my Champ I had a hard time on landing it when flying alone since I was used to having the instructor in the back seat. My Champ also has a much heavier engine up front which made it even worse than a stock 65 HP plane. I ended up putting a bag of Quickrete in the back seat for a few more hours of flying time til I got more aquainted with the paculiarities of the Champ. Once I was more comfortable with the plane I took it out and now I don't even notice that I need a little back pressure on the stick with full nose up trim.
Keith

Dan1940Chief
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Re: Trim

Post by Dan1940Chief »

Solo in my Chief full nose-up trim gives me 58 mph.

So I usually crank it all the way then back one half turn (also keeps the handle from bumping my head).

Once the runway is made I crank it full yet still have to pull back to achieve short final speed of 50 mph.
-----------------------------------
Dan McCormack
http://flightmusings.blogspot.com/
1940 Aeronca Chief LA-65
NEW Home Airport: S37 (Smoketown, PA)

Red(neck) Barron
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Re: Trim

Post by Red(neck) Barron »

I've got a 90 in my Champ and I'm a heavy guy so I can't trim for 60 when I'm solo either but it's about right with a passenger. I guess I'd rather fail on that side than to have more nose up trim and possibly put myself in a situation with full nose up trim, a passenger and a sudden go around close to the ground and potentially pitch up into a stall.

I'll be interested in hearing others comments on this one since I had never given it any consideration before.
Larry H
Sigourney, IA
Formally N84619, N84149 & N84069 - all1946 7AC's; also N57430 a 7ECA
Currently N91RA 7GCAA (Still a Champ, just grown up some)

Dan1940Chief
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Re: Trim

Post by Dan1940Chief »

Red(neck) Barron wrote:I've got a 90 in my Champ and I'm a heavy guy so I can't trim for 60 when I'm solo either but it's about right with a passenger. I guess I'd rather fail on that side than to have more nose up trim and possibly put myself in a situation with full nose up trim, a passenger and a sudden go around close to the ground and potentially pitch up into a stall.

I'll be interested in hearing others comments on this one since I had never given it any consideration before.

A pilot of a Chief of champ or Cub who can't hold the nose down after applying full power for a go-around needs to stop flying and work out some.

:D

Airplanes certified under CAR (later FARs and now CFR) have design constraints, including the amount of force required to overcome that very condition (full power, aft CG, full nose up trim).
-----------------------------------
Dan McCormack
http://flightmusings.blogspot.com/
1940 Aeronca Chief LA-65
NEW Home Airport: S37 (Smoketown, PA)

Red(neck) Barron
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Re: Trim

Post by Red(neck) Barron »

You are assuming that all pilots are on the plus side of the 'average intelligence' marker. I happen to know better.
Larry H
Sigourney, IA
Formally N84619, N84149 & N84069 - all1946 7AC's; also N57430 a 7ECA
Currently N91RA 7GCAA (Still a Champ, just grown up some)

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rkittine
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Re: Trim

Post by rkittine »

The way my 7AC was converted to a 7CCM required the Up Travel on the elevator to be restricted. Full aft trim with just me in the plane results in needing back pressure to get below 70 with a wind milling prop and about 65 with someone in the back seat.

Years ago my Tail Wheel instructor made me fly with trim neutral at all times, then with full forward trim and then with full rear. He was not an advocate of flying with a lot of trimming, especially in older planes. I do that now with my students also as they usually want to trim all the time.

Crusie trim does work pretty well on my Champ.

With the Vortex Generators, I need forward trim on take off as well as full stick forward to get the tail up as even solo from the front seat, it wants to fly way to early.
Robert P. Kittine, Jr.WA2YDV
West Nyack Aviation, L.L.C.
New York, New York 631-374-9652
rkittine@aol.com

MikeB
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Re: Trim

Post by MikeB »

Actually the amount of fuel you have in the nose tank also affects the needed trim. One benefit of the 13 gallon wing tanks is better balance and stops the necessity of retrimming during longer flights as fuel is burned off. A minor point but.......... :roll: .

MikeB

Paul Agaliotis
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Re: Trim

Post by Paul Agaliotis »

I just fly it from the back. It's real easy to get the CG way forward.
When going cross country my load schedule put the CG pretty close to the aft limit. It makes the plane fly different ,but it's a little faster.
Paul
Mailing Adress : Paul Agaliotis 2060 E. San Martin, San Martin,Calif. 95046

MikeB
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Re: Trim

Post by MikeB »

Except my L16 (7BCM) is placarded "Solo Front Seat Only (For the whatever it's worth department). I've flown my Champ from the rear seat but never the L16. It seems to pick up speed really quick on landing with solo in front. Might be worth a try except the master and starter buttons, etc. are in the front....

Mike

Paul Agaliotis
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Re: Trim

Post by Paul Agaliotis »

Mike,
You can't get out of the thing with a chute on when you're in the back. But one other weird thing, my TAC is placarded rear seat solo and the L3 variant is front seat solo for the same reason.
Paul
Mailing Adress : Paul Agaliotis 2060 E. San Martin, San Martin,Calif. 95046

DC Krog
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Re: Trim

Post by DC Krog »

I don't think your trim is rigged correctly. You should be able to check the correct angle in the Service Manual. (I don't have one in front of me right now) But the exact angles are listed in the Service Manual and the trim tab can be adjusted via the two turnbuckles located on the tab.

DC Krog

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sburke
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Re: Trim

Post by sburke »

I have an L16A which requires some back pressure on the stick with the engine at idle in order to hold an airspeed of 65mph during my final approach with the trim set full nose up. I asked my AI to check the trim tab adjustment during a recent annual, he reset it according to the manual but no change. I think it may be due to the fact that my aircraft has a starter, generator, battery and a metal prop which has moved the CG forward of the original CG which did not include these items. The CG range for my L16A is 10.4in - 19.7in according to the FAA Type Cert. With full fuel and me in the front seat my CG is calculated at 11.19in which is way forward. If I went to a wood prop, removed the starter, battery and generator I think I could trim for 60mph at engine idle. In order to make it easy to hold 65 to 70 mph on final with the engine at idle I have used a grease pen to draw some lines on the inside of the wind screen which I use to hold one of the lines on the horizon to maintain the correct approach airspeed. If I do this it is not necessary to look at the air speed indicator, this is called attitude flying I think. Remember, one is less likely to get hurt with a forward CG!
Regards,
Sam
Sam Burke
Santa Ynez, CA
N6404C L16A 7BCM-296 USAF 47-1076 C85-12F
8056862323
sburke@charm.physics.ucsb.edu

gusc
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Re: Trim

Post by gusc »

Many airplanes need rear seat loading or baggage to land easily, all the smaller Cessnas are like that. Some are impossible to flare properly with full flaps without power.
Gus Causbie
Ash Flat, AR
N83564, 7AC-2235, A65-8

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