Is elevator trim tab with piano hinge more effective?

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akholland
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Is elevator trim tab with piano hinge more effective?

Post by akholland »

Have the old style m4/m5 trim tab. It won't trim out for approach. Will the piano hinge type of elevator tab like on a m7 provide more trim? [/i]

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Mog
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Post by Mog »

Would think an impromptu gap seal would answer that question.

I usually just get it close and man handle it from there, my finals are way to slow to establish a truly stabilized approach.

Kirk
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Post by Kirk »

My M5 trims up rock steady. Have the control and trim cable tensions been checked? First indication I’ve always had of loose tensions is wandering and some difficulty in trimming.

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plowboy
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Post by plowboy »

If you trim for approach, you lose 20% or more of your elevator authority; As it is on the outboard end of your elevator. Those in the know say do not trim, just muscle it so you have more elevator bite at slower landing speeds. Or so I have read, and I do.

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Post by plowboy »

:oops:
Last edited by plowboy on Tue Apr 16, 2019 6:23 am, edited 1 time in total.

Dale Smith
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Post by Dale Smith »

I am in the process of changing over to the new style hinge on my M5. I will try to give some feed back on that once I get done.

My M5 235 you can trim it hands off on approach with one person and half fuel, and that is well to the front of the CG curve.

I don't use the trim past about half way back though. Your right arm will become used to the pressures it takes to be at the attitude you want. I have found that it helps me fly a more stabilized approach with just your arm. The other advantage is that you dont have to force the nose down for a wheel landing, and the plane does not want to point straight to the sky for a go-around.
No great story started with a good idea...

Dale Smith
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Post by Dale Smith »

you could also check to see how the trim tab is rigged. The manual should have the degree's for both directions of travel.
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akholland
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Post by akholland »

Good point on the tension I'll go check that this morning. It's a 235 but even so I'd hope I could trim it to approach at least 65 on its own. Going to play with it ill get back with results.

Also Yesterday was noticing slop in my flaps where I wasn't getting full deflection under load. Culprit was that gust lock. Needs to go byebye.

Does anyone put half a degree wash out into the wings or do you run them flat. I get a oil canning bad when adding wash.

Kirk
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Post by Kirk »

If you do eliminate the gust lock, make sure you install the flap limit cables. They keep the flaps from blowing down far enough to scratch the rear window and potentially damage the rear spar.

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akholland
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Post by akholland »

So I did have a little slop in my trim cable. Also tightened up the flap turnbuckle so now my flaps actually stay down 40 degrees during landing instead of 15, however now their hanging down 4 inches unless the air is holding them up in flight. Gust locks fault I presume. Springs are good.

Time to find some piano hinge and get started on the m7 trim tab.
Approach speed full up trim full flap is 65 without elevator input, no flap approach trims out at 95mph. Still lacks some trim but much better with more flap. Not so sure what u mean by gap seals on the trim tab. Maybe u meant the elevator. Already have those.

Looking at the gust lock I need to build a bracket to hold the return spring. Should be easy.

My only gripe now is the rudder is too small and tail too big. Got a cross wind gust hanging her off the prop and about went in the trees. Then went to take back off and about stuck it in the trees again when the p factor hit and the rudder ran out. No short takeoffs in this pig. Hoping the long cord m7 rudder helps. I prefer the m4 tail far more, crosswinds are a non issue and it's far more responsive.

Back to work

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Mog
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Post by Mog »

The trim tab on the M4 leaves a gap between its leading edge and the trailing edge of the elevator. Installing a gap seal between the elevator and the trim tab will increase the effectiveness of the trim tab. Worth a shot anyways.

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