Flap Spring - Solved

[Paul - M20C]

We have figured it out. 

Those that said a stiffer spring would only mask it are correct.  In this case a stiffer spring wouldn't have even masked it though.  The trailing edge of the skin on the wing at the outer most part of my left flap is slightly lower than the rest of the wing.  By shining a flashlight across it you can see where it was bent and then bent back up leaving a lower portion than the rest of the wing.  The forward seam in the flap skin catches on the trailing edge of the wing when the flap has pressure applied from below (air pressure in flight - simulated on the ground).   My mechanic will be looking into this further and hopefully it won't be too expensive of a repair. 

Thanks for the replies.

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My left flap isn't always returning all the way up in flight.  My mechanic says it looks like the spring should be replaced.  A quick Google search only resulted in one find from Texas Air Salvage from a 1966.  I was hoping to locate new springs.

Anyone have a source for flap springs "750019-7" for my 1965 M20C?  

 

Edited August 22, 2018 by Paul - M20C
Resolved - Edit added

[N201MKTurbo]

The spring is just there to bring the flaps up on the ground. While flying the air loads will push the flaps up. 

If one is not going up to the stop in flight then something is rigged wrong.

[Paul - M20C]

54 minutes ago, N201MKTurbo said:

The spring is just there to bring the flaps up on the ground. While flying the air loads will push the flaps up. 

If one is not going up to the stop in flight then something is rigged wrong.

Good to know.  We'll go back and inspect again.  Thanks.

[Jim Peace]

14 hours ago, Paul - M20C said:

My left flap isn't always returning all the way up in flight.  My mechanic says it looks like the spring should be replaced.  A quick Google search only resulted in one find from Texas Air Salvage from a 1966.  I was hoping to locate new springs.

Anyone have a source for flap springs "750019-7" for my 1965 M20C?  

 

I had this issue and put up my replacement spring that was suggested by Mooney with pictures.  Will try to find the thread

[Jim Peace]

can't find the thread but Mooney told me to use:

Part number: LE105G09M  NSPP LEE Spring 

I bought it from Radwell International.  I remember I had to buy 10 of them and I used two and sold some to a MSC.

47 dollars total for the 10 in 2016.

seems like a much higher tension than the factory, but I was comparing a new one to one that was over 50 years old.  You may have to adjust the pressure on the flap return mechanism to limit the pressure so they don't go up to fast.  Other than that they have been great.

[carusoam]

Nice pic, JP!

Do they stay that shiny over time...?  Or are they the same as the 1960’s original...

Best regards,

-a-

[Jim Peace]

After you put the higher tension springs on you will have to turn this screw to slow down the retraction.

[Guest tommy123]

If the flaps aren’t retracting in flight it isn’t the spring, you have another problem. Putting in a heavier spring will only mask the problem.