Ailerons high in trail

[FloridaMan]

On my F, the ailerons look the same in flight as they do on the ground — aligned with the flaps when the flaps are up. On the rocket, the ailerons are even with or slightly lower than the flaps on the ground, but float up as much as an inch on both sides at the same time in flight. Lifting on the ailerons together on the ground with help from a friend will pull them both up without much force, like they’re bungeed together in the middle. I’ve not seen this before and I suspect it’s spoiling lift and affecting climb and cruise performance. 

Before sending it off for rigging, I’d like to understand a bit more about what would cause this. 

[jetdriven]

what you are seeing is the slop in the aileron control system.  So you have 16.75lb per sqft of wing loading. Those ailerons are 3-4 sqft. So they have 50-67 lb of force lifting them upwards in flight.

Either start replacing stuff to get the slop out, or rig them lower so they fly level in cruise. Check the ailerons with rigging boards, while holding both up with 20-50lb of force, to be sure the flaps arent 2 degrees down instead of the ailerons looking high.

[INA201]

My J has ailerons float up to even with the flaps in flight. Also, just had rigging checked at an MSC and they made a minor flap and rudder adjustment but don’t recall ailerons being mentioned.  My left flap would come in and hit the stop early causing a very minor twist in it. Rudder was off of spec by a degree or so. Probably going out today I hope and will take a pic.

[jwilcoxon78]

My ailerons do the same on my J.  MSC said they wouldn't bother with it but I'll likely have them or someone else check it out down the road.  It does seem that it would take some efficiency out of the airframe.

[N201MKTurbo]

I did a lot of messing with the rigging on my old F model. My data showed the higher you rig the ailerons the faster the plane flies. I wouldn't be in any hurry to lower them. You will probably be disappointed with the results.

[cujet]

I flew in Antares' Rocket yesterday. The ailerons fly an inch high as mentioned. 

After the flight, we pulled up on both ailerons simultaneously. With only minor force, both pulled up to the inch up position. With roughly 40 pounds up force on the trailing edge, both pulled up to near the maximum deflection point. With a very "springy" feel. 

I've never worked on an airplane that is configured with "flexible" aileron rigging. However, I have near zero Mooney experience. 

Not knowing the system, it's my guess that there is too much "give" in the aileron mechanicals and I don't believe having them reflexed up near 50% of normal travel helps flight control feel. They feel stiff and unresponsive, even for a Mooney. I understand Rockets are heavy. But this seems unusual to me. 

[cujet]

33 minutes ago, N201MKTurbo said:

I did a lot of messing with the rigging on my old F model. My data showed the higher you rig the ailerons the faster the plane flies. I wouldn't be in any hurry to lower them. You will probably be disappointed with the results.

There is some truth in that. Reflexed ailerons can provide a speed advantage in certain conditions. Whether that applies to a Rocket, with lots-o-weight on the nose and 1 inch up on both ailerons, is another matter. Having flown in the above mentioned aircraft, it is significantly below book speeds at rated power. 150Kts indicated at 18K just seems low. It could be drag related due to high tail loading. 

[N201MKTurbo]

If they are springy, there is something seriously wrong. I would take a close look at the aileron links in the belly, they are the only thing that could become springy, and only if they were failing. I've been flying a rocket lately and it should be doing over 200 KTS true at 18K

Edited August 7, 2018 by N201MKTurbo

[N201MKTurbo]

Actually, 150 IAS at 18000 with an OAT of 0C is 204 KTS. That's about right.

[FloridaMan]

I was indicating around 155 at 16000 on the way up there and 145 at 4 OAT and 147 at FL230 and -8OAT. Both at 76% power