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Take Off Trim?

Champ

Well Known Member
Wonder what others do with elevator trim setting on take off? I generally take off with no flap and with trim left where it was on last final. With this it seems to fly off when ready and only slight back pressure on the stick and no trim change on climb out. This is when solo and although my battery is in the back and a CS prop I still consider it nose heavy. Also - would you change take off trim with different flap settings and c of g?s?
 
Maybe sloppy on my part, but I never really think about. With the trim on a hat switch on top of the stick, I just adjust the trim when the airplane starts flying. Some times it?s pretty far off, especially if the last time I landed was with a passenger, but the stick pressure is always quite manageable.
 
Wonder what others do with elevator trim setting on take off? I generally take off with no flap and with trim left where it was on last final.
I routinely use partial flap for takeoff, but for trim, I do the same and leave it on the 'landing' setting.. Even though I have the trim position showing on SkyView, I don't bother with it until I am established in the climb. Stick forces, even with what I would call quite out of trim, have always been very easily manageable.
 
Landing setting as well. I just can't turn my head enough to see the trim in my 7. Seems to work. Stick back until full power then let the tail come up, or ease it up.
 
neutral trim

In my -6 I always set trim to neutral for takeoff. In my plane that results in a positive rate of climb with little/no stick pressure.

The landing trim setting produces a significant pitch up if you remove pressure from the stick on takeoff/climb-out.

I was always taught to keep the plane in trim for the desired flight attitude, you never know when you'll need to remove your hand from the stick for a moment. Stuff happens.
 
Everything He Said

In my -6 I always set trim to neutral for takeoff. In my plane that results in a positive rate of climb with little/no stick pressure.

The landing trim setting produces a significant pitch up if you remove pressure from the stick on takeoff/climb-out.

I was always taught to keep the plane in trim for the desired flight attitude, you never know when you'll need to remove your hand from the stick for a moment. Stuff happens.

+1

IO-375, Hartzell CS prop, Electric Trim. Neutral trim point displayed on Dynon Skyview EMS display.
 
RV-8 TO Trim

In my RV-8 I typically end up with a lot of nose up trim on landing so I definitely don't want to take off with it that way. For takeoff solo I set the pitch trim neutral, for takeoff with someone in the back I set it slightly nose down. I leave my flaps down after landing to make it easier to get in and out. So after start I bring the flaps back up and set the trim. I also do a check of trim/flaps/controls in my pre-take off checks.
Cheers
Nige
 
In my -10 I also set the trim at neutral for takeoff. I found out soon after I started flying it during touch and goes that if I left the trim set for landing when the power come up and the flaps retract, there is a strong nose pitch up.
 
If we think about what pitch trim is for (provide a means of trimming the aircraft for a specific speed, flap configuration, and C.G. position), it should quickly become obvious that comparing settings from one RV model to another is pointless. Even comparing two of the same model may not be useful depending on the C.G. that is typical for landing.

I have walked the flight line at fly-ins and have seen trim tab positions (likely still where they were at landing), in positions from one extreme to the other (nose up and nose down).
Sometimes even a lot of nose down (a strong indicator that the airplane was at or maybe even beyond the aft C.G. limit).

For most RV's the ideal trim tab travel is such that allows about 30-35% of the travel to be nose down trim, and the remainder to be nose up trim.
This will allow for being able to trim for a normal approach speed at full flaps at C.G.'s typical for landing (though it still may not be enough when near the fwd end of the C.G. range).

The ideal trim setting for take-off will vary with C.G., but because the control forces on RV's are lighter than many production aircraft, as long as you are close, take-offs are generally not a problem and you can make a small adjustment once stabilized in a climb.
Having said that, my opinion is that every RV should have means of easily determining the pitch trim setting for take-off. Doesn't have to be fancy. For my manual trim RV-6A it is knowing that it is at neutral when the knob is about 1" aft of the fwd limit (no other indicator required).

A take-off with a grossly maladjusted pitch trim (because of having landed with a majorly aft C.G.) can cause quite a surprise, and in some conditions require some major effort on by the pilot to counter act.
 
In my RV-8 I typically end up with a lot of nose up trim on landing so I definitely don't want to take off with it that way. For takeoff solo I set the pitch trim neutral, for takeoff with someone in the back I set it slightly nose down. I leave my flaps down after landing to make it easier to get in and out. So after start I bring the flaps back up and set the trim. I also do a check of trim/flaps/controls in my pre-take off checks.
Cheers
Nige


Nigel I do exactly the same as you do and for the same reasons in my -8.
 
Smoke and mirrors...

Ok, no smoke, just mirror. Even though I put it on my checklist, I always seem to forget to neutralize trim setting before the canopy is closed. I bought a cheap little automotive sun visor mirror that now lives beside my seat. I can hold it up and just see my trim tab if I raise the elevator. Now I can check and adjust more easily.
I found that especially on rough field t/o, not having the tab neutral can create some undesirable extra effort, as I try to get the tail up as quickly as possible.
 
I'm with Nigel et al;
Except that I have manual trim, and roll in a couple of half turns nose down, especially if there is a back seater.
I usually take off with flaps, about 20%. Adding flaps moves the center of lift aft a bit, and I did land with full flaps, so it makes sense to me.
I don't like an 'up trim' take off, although they are easily controlled. I just worry that 'popping up' on takeoff, combined with a distraction could cause a take-off stall, so I'd rather pull the plane off than hold forward on take off.
That's funny, because I cruise trimmed for a slight climb, and hold a slight forward pressure.
Go figure.
 
neutral.

Just what we do. Before I shut down, I look at flaps and trim to set them to down and neutral. That gets them ready for the next flight and helps with pre-flight checks and walk-arounds while working in the hangar. We have electric trim with Ray Allen, pitch and roll with the LED markers in the panel so it is not hard to adjust as you need it to suite load and speed levels. Just a check list kind of thing. Hope this helps, Yours, R.E.A. III #80888
 
Electric pitch and roll trim (RAC) on my 7A. Both set to neutral for take-off (actually, just prior to shutdown on the previous flight, then verified prior to take-off). Dynon SV pitch/roll trim indicator.

Flaps go up after turning off the runway, then down prior to shut-off, to prevent damage from gravel, etc. Then up prior to start-up and taxi out for take-off.

And, yes, all of those items are on the checklist :).
 
In my -6 I always set trim to neutral for takeoff. In my plane that results in a positive rate of climb with little/no stick pressure.

The landing trim setting produces a significant pitch up if you remove pressure from the stick on takeoff/climb-out.
This is my general procedure as well. Well, except for 50% of the time when i've forgotten to reset the trim to neutral, and then have to spend a few seconds holding forward stick and dialing it in the trim as I climb out...
 
Manual flaps and trim here. I usually take off with 1 notch of flaps (puts the flaps at the same angle as full down aileron deflection) and a little nose down trim. My thought here (tell me if I'm wrong) is that if engine fails after takeoff, it will require lot's of nose forward stick to get on glide speed. If I already have neutral or nose up trim, it will require more force to maintain glide speed. After raising the flaps, I adjust trim pitch for climb speed.
 
Manual trim

I use full flaps for every landing and that needs full nose up trim (1/2 fuel or less). For take-off with flaps up I turn the trim nose down 1 full turn.
 
OP Note

Thanks for all the input. The what if the engine quit especially got my attention. Neutral trim makes a lot of sense. I?ll have to test what?s best for aft c of g?s. Compared to my Champ out of trim stick forces in the RV are pretty light.

Still learning every time I fly and whenever I check VAF.
 
Im not so sure what is being said here. I believe way more people stall with loss of engine than nose dive into the ground. Would it make sense to be nose heavy with trim on takeoff? Im a new pilot so I would like to learn something here.


Manual flaps and trim here. I usually take off with 1 notch of flaps (puts the flaps at the same angle as full down aileron deflection) and a little nose down trim. My thought here (tell me if I'm wrong) is that if engine fails after takeoff, it will require lot's of nose forward stick to get on glide speed. If I already have neutral or nose up trim, it will require more force to maintain glide speed. After raising the flaps, I adjust trim pitch for climb speed.
 
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