Van's Air Force
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Elevator position in cruise
- Thread starter N523RV
- Start date
Kevin Horton
Well Known Member
Do you have all your fairings and wheel pants on? If not, wait until the aircraft is in its final state before you do anything. The elevator angle in cruise will vary with cruise speed.
Raising the nose of the HS with a shim will allow the elevator to be more in trail in cruise. Figure out how many degrees the elevator is out of the trail position. Shim the HS up about 40% of this angle. E.g., if the elevator is deflected down 1 degree, you want to shim the HS up about 0.4 degrees.
The difference in performance will be very small, probably too small to measure. It may not be worth the hassle of making a new empennage fairing.
Raising the nose of the HS with a shim will allow the elevator to be more in trail in cruise. Figure out how many degrees the elevator is out of the trail position. Shim the HS up about 40% of this angle. E.g., if the elevator is deflected down 1 degree, you want to shim the HS up about 0.4 degrees.
The difference in performance will be very small, probably too small to measure. It may not be worth the hassle of making a new empennage fairing.
Kevin Horton
Well Known Member
I hate fibreglas work so much I would solve the problem by not looking back in cruise. Those Cessnas aren't goint to hit you from behind anywayN523RV said:
OneTwoSierra
Well Known Member
same...
Mine is the same - 0320, catto prop - up about 1 inch. It was the same with and without farings, although I agree any adjustment should be made with those installed because you never know what impact they may have.
A buddy of mine had this same condition on his RV6. It bugged the **** out of him. (Personally, it doesn't bother me too much, although I'm sure I'm loosing a few knots because of it. But I digress.) He put washers underneath the front mounts of his HS to raise it just a bit and reported to me that it solved this issue. I'm considering at annual creating spacers for underneath the front HS angles/mounts to see what impact it has. I'm sure a little goes a long way. I have wondered if the fairing would be impacted noticably.
Has anyone else done this?
Mine is the same - 0320, catto prop - up about 1 inch. It was the same with and without farings, although I agree any adjustment should be made with those installed because you never know what impact they may have.
A buddy of mine had this same condition on his RV6. It bugged the **** out of him. (Personally, it doesn't bother me too much, although I'm sure I'm loosing a few knots because of it. But I digress.) He put washers underneath the front mounts of his HS to raise it just a bit and reported to me that it solved this issue. I'm considering at annual creating spacers for underneath the front HS angles/mounts to see what impact it has. I'm sure a little goes a long way. I have wondered if the fairing would be impacted noticably.
Has anyone else done this?
Kevin Horton said:I hate fibreglas work so much I would solve the problem by not looking back in cruise. Those Cessnas aren't goint to hit you from behind anyway
Besides Kevin, we've got -8's....with loading options from the forward to the aft baggage compartment, you're sure to find a CG location that gives a neutral elevator in cruise!
Paul
pierre smith
Well Known Member
Down elevator
Hi Andy,
From the picture, your elevator appears to only be down around 1/4" or so, which is what the Manual says it should be. With two people aboard and full fuel, the CG shifts rearward anyway so don't adjust anything yet. Besides, a rearward loaded airplane is faster because the load that the elevator is carrying decreases the load on the wing and consequently less angle of attack.
Pierre
Hi Andy,
From the picture, your elevator appears to only be down around 1/4" or so, which is what the Manual says it should be. With two people aboard and full fuel, the CG shifts rearward anyway so don't adjust anything yet. Besides, a rearward loaded airplane is faster because the load that the elevator is carrying decreases the load on the wing and consequently less angle of attack.
Pierre
