M20J electric cowl flaps won’t stay fully closed

[IslandPilot]

Been tolerating this for too long without asking about it.  After fully closing cowl flaps during cruise flight, the cowl flaps slowly move to about one fourth of the way open.  How normal is this?  I return the switch to the off position after closing.  I don’t leave the switch in the close position hoping to avoid overworking or burning out the electric motor.  Cowl flaps are working normal on the ground, and they stay closed with moderate manual tugging on the cowl flaps.   I looked at all the linkage mechanisms under the cowling, and apparently the design does not use an over-center technique or any other technique to lock the cowl flaps fully closed.  Maybe the air pressure pushing on the cowl flaps is causes the gearing and electric motor to rotate until that force is balanced by the resistance of the mechanical linkage.  Clarification would be appreciated.  Thanks.

[PT20J]

I close mine and leave the switch in the closed position. It shouldn't make any difference because the limit switch turns off the motor, but it might mask any tendency for them to open in flight. I'll try to remember to put the switch in the off position and see if they move.

How long after you close them does it take for them to open?

Skip

[carusoam]

Hhhmmmmmm….

As far as how normal this is…

Its a sign of wear or mal-adjustment… but what part would be the next question…

My Mooney doesn’t have cowl flaps…

On My M20C… clamps holding the flaps mechanism at the engine mount were sliding around…

Best regards,

-a-

[laytonl]

I know mine did that too, so I always leave mine in the up position.  However, since having the motor overhauled I have noticed it does seem to stay up even if the switch is off.  Lee

[PT20J]

My cowl flap position indicator stopped working today, so I can’t tell until I fix it.

[PT20J]

On 1/13/2023 at 12:24 PM, IslandPilot said:

Been tolerating this for too long without asking about it.  After fully closing cowl flaps during cruise flight, the cowl flaps slowly move to about one fourth of the way open.  How normal is this?  I return the switch to the off position after closing.  I don’t leave the switch in the close position hoping to avoid overworking or burning out the electric motor.  Cowl flaps are working normal on the ground, and they stay closed with moderate manual tugging on the cowl flaps.   I looked at all the linkage mechanisms under the cowling, and apparently the design does not use an over-center technique or any other technique to lock the cowl flaps fully closed.  Maybe the air pressure pushing on the cowl flaps is causes the gearing and electric motor to rotate until that force is balanced by the resistance of the mechanical linkage.  Clarification would be appreciated.  Thanks.

Sorry to take so long to reply -- had to fix my broken cowl flap position indicator first. No, my cowl flaps stay closed in cruise flight with the switch in the center (OFF) position. I also notice that they stay in partially open positions in cruise flight.

Skip