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Piper9t3

Elevator Surface Positions

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Hi

On route to PAJN this morning and I need to ask why my left and right elevator surface positions are deflected downward when in level, stable flight?  The indication on the PFCS can be seen on the attached image and the corresponding position of the elevators is shown below:

 

 

 

 

 

This does not seem to affect the flight dynamics when in cruise and AP is engaged.  When I try to adjust the elevator trim there is no response.  I use a CH Eclipse flight yoke which I am certain is properly calibrated.  Any suggestions or advice would be much appreciated!

Thanks

 

 

 

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The Dash has no elevator trim tab. Its a one piece elevator. If it weren't deflected down, you would fly off to the moon.

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So you are saying that the downward indication on the PFCS is normal during level flight?

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This might be completely different but your question reminded me of something I noticed in mine. While in cruise I noticed it appeared to me that when looking at a side view of the fuselage in external camera mode, the Q400 has a slight nose down attitude at cruise. Now did it just appear that way or could it have been due to the loads in the aircraft I don't know, or maybe thats normal for a high wing liner. Anyway in my quality low wing airliners they have a slight nose up attitude while in cruise, just like the pictures I see of the real aircraft.

 

Next time I fly the Q400 I will have to check my elevators more closely while in cruise. I find it hard to believe the elevators in your pic would be considered normal at cruise, and it appears it would certainly cause some drag and a slight nose down attitude, but what do I know?

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Next time I fly the Q400 I will have to check my elevators more closely while in cruise.

 

Please do post your findings...interesting to see if others have the same elevator position in cruise.

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Please do post your findings...interesting to see if others have the same elevator position in cruise.

I've noticed this myself even with MAC near dead center. It's always trimmed pretty far nose down when on autopilot. Whether it's normal, I don't know. Also, I don't recall noticing an actual nose down attitude in cruise when viewing from the outside and I seem to recall it being right at 0 or +1 degree on the ADI. I know if you look at the dash from the front (looking towards the props) it appears nose down but I think that is an illusion caused by the high "shoulders" that the high wing creates.

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Well I just completed another flight and report that as per my OP, the left and right elevators are deflected downward as indicated on the PFCS when in level flight and AP engaged.  The attitude indication on the PFD shows 0 pitch and when I disconnect the AP, the aircraft remains level with no sudden pitch down suggesting the aircraft is properly trimmed.  Seems like that is the norm I guess?  No complaints though, really enjoy this bird...

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It is normal.  Since there is no trim tab, the whole elevator moves to adjust pitch trim.  Move you're MAC farther forward and that downward trim will decrease.

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It is normal.  Since there is no trim tab, the whole elevator moves to adjust pitch trim.  Move you're MAC farther forward and that downward trim will decrease.

Yep :-)

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MAC ?

 

Mean aerodynamic chord, basically where the centre of the lift force is.

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Mean aerodynamic chord, basically where the centre of the lift force is.

Thanks for the explanation. 

 

It is normal.  Since there is no trim tab, the whole elevator moves to adjust pitch trim.  Move you're MAC farther forward and that downward trim will decrease.

Matt exactly how do you move the MAC forward? 

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Move the cg forward.  When you load the aircraft, load more weight into the front than into the back!

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Move the cg forward.  When you load the aircraft, load more weight into the front than into the back!

Of course!  That's what I thought. 

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