Stabilator AD 94-13-10

[Clarence Beintema]

I posted this on the Delphi forum as well as here.

I thought I would share this with everyone as it effects all Comanches, single and twin.

While doing the Annual on my 400 and complying with AD94-13-10 I heard some noise from the tail section. Further examination revealed that there was a very small amount of movement in the lower fittings.

My wife was able to locate a NOS (new old stock) complete repair kit as called out in Piper SB 411A. I spoke with Phillip at Webco who advised that they have an AMOC to the AD whereby you do not have to cut access holes in the fuselage skin, they remove rivets and peel back the skins to allow access.

The thought of cutting holes or peeling skin off my plane was not appealing. After studying the structure and looking at the parts on a spare PA30 we are parting out, I decided the job could be done with with no holes or peeling of skin. I removed the stabilator torque tube, bearings and balance weight arm. With these out of the way I was able to knock the lock collars of the steel rivets working through the holes in the rear most bulkhead.

Contrary to the instructions I removed the lower fitting assembly from the plane, this allowed easy access to the upper two fittings. Following the instructions for the upper fitting, I removed the one rivet at a time, then with a selection of small reamers I enlarged the holes to fit the new structural screws. Once all of the upper fasteners were installed and torqued I reinstalled the lower fitting assembly and reamed the holes and installed the new structural screws.

Now I just have to reinstall the stabilator torque tube and bearing.

Clarence