Control Bungee springs and cables

[RRHall]

I was helping someone with their PA-20 elevator the other day and noticed there were springs attached to the elevator horn going to something in the parts manual called control bungees. My PA-22-108 tailwheel conversion project I have been restoring has no springs or Bungee cable. Does anyone know if the colt had these or if they were removed as part of the Univair tailwheel conversion or if I need to install them. I am also wondering what is their purpose.

[Gilbert Pierce]

All ShortWings except the Vagabond had them. These were necessary for the airplanes to pass the FAA longitudinal stability requirements and are part of the Type Certificte. I have flown a Clipper that had these removed. I thought it had less stability then the one’s I flew that had it, like mine. Others like having them removed. I personally would not sign of an annual that had them removed.

[Paul Watts]

Colts did not have the aileron / rudder interconnect.


Edit: OOPS, I misread the post; Yes, I agree with Gilbert; the elevators are connected to the horizontal stabilizer with those springs (and brackets, and cables)

[RRHall]

I guess another task to be added to the 1,001 things I need to do for this plane. I will have to check and see if any f the parts are there or if I need to install everything.

[andya]

Gilbert
Have you ever heard what the purpose of the single spring in the Vagabond was for, the one that helps hold the elevator in the up position.
Had to change mine as it was not strong enough to hold up against the stop in a ground static situation.
Initially when I found a problem with it, it was not connected to the correct place and need to be stretched further fwd.
Did not take care of the discrepancy totally so I ordered a new spring and made a new cable per the Vag Dwgs.
Now it's the way it is suppose to be but not sure what it is suppose to do for me.

[Gilbert Pierce]

I seem to remember Clyde Smith or maybe an early publication like Air Facts. I'll try and find it and post it.

[Gilbert Pierce]

OK here is the answer but you have to read the article and then post the answer. Hint Horsepower.

[51-pa22]

Gilbert
Thanks for the link.
Great read.
Any idea how they determined the VNE on the ShortWingPipers?

[Gilbert Pierce]

Stress calculations with a Slide rule?
I used to be a whiz with one, thought I died and gone to heaven when the TI10 came out. Then the HP25 wow.

[51-pa22]

Dang. That hurt!
And I thought I was a real stud to have a transistor then!