Rudder lock possible?

[Michael Wellenzohn]

Hi,

I did a couple days ago a stability test flight to check how the aircraft behaves when you apply full rudder in climb, cruise and descent with full flaps.

In climb at about 100 kt with wings level I applied slowly more and more right rudder until I hit the limit. that process took a couple of seconds about approximately an inch before the limit the rudder got soft and locked aerodynamically. I immediately gave opposite rudder to go straight again.

My question now is if other experienced this as well, would it come back and I just need to wait a bit? I guess one is expected to give full rudder more swiftly and check the behavior then. If you apply it slowly the aircraft is at so much slip that the bigger part of the rudder is covered by the VS near the end of its range and only the counter balance gets the airstream, just a guess though.

I replicated this about four times left and right in cruise and climb. Interesting enough that in landing config at 70kt it did not appear but it might be that I pressed the rudder more swiftly du to the speed loss when you yaw the aircraft.

Regards
Mike

 

[aerhed]

Very interesting colonel Hogan. Does the rudder feel
Like it's in a detent? How much force to push it back out?

 

[Wayne Gillispie]

My RV-10 Full Flap Limit= 87 KIAS

Hi,

I did a couple days ago a stability test flight to check how the aircraft behaves when you apply full rudder in climb, cruise and descent with full flaps.

In climb at about 100 kt with wings level I applied slowly more and more right rudder until I hit the limit. that process took a couple of seconds about approximately an inch before the limit the rudder got soft and locked aerodynamically. I immediately gave opposite rudder to go straight again.

My question now is if other experienced this as well, would it come back and I just need to wait a bit? I guess one is expected to give full rudder more swiftly and check the behavior then. If you apply it slowly the aircraft is at so much slip that the bigger part of the rudder is covered by the VS near the end of its range and only the counter balance gets the airstream, just a guess though.

I replicated this about four times left and right in cruise and climb. Interesting enough that in landing config at 70kt it did not appear but it might be that I pressed the rudder more swiftly du to the speed loss when you yaw the aircraft.

Regards
Mike

I did not test that flight regime. Imagine if one flap departed and how your little ailerons would counter the roll. It happened in a Cherokee one time. He rolled and ended up losing a wing too.

 

[n5lp]

I remember encountering something similar to what you describe in a Schweizer 2-33 under certain circumstances. Rudder pressure goes away and full rudder deflection will be maintained with feet off the rudder pedals. You need to apply opposite rudder to restore normal feel. Somewhat disconcerting but I'm not sure it is an important issue. The 2-33 is a factory aircraft.

In my first flight in an RV-6 (Old Blue) I noticed that during deceleration to the stall the back pressure stopped increasing and started decreasing at some point. I noticed it then but never again.

These things may not be the ideal, but they may not be a big deal either.