Posted Tuesday, February 3, 2009 @ 00:30 AM
Hi Folks,
It's HDO's annual inspection time.
She's forty years old now, and since I've owned the poor little thing for five years and treated her pretty hard in that time, I decided to take her apart and do some big repairs, plus a few little things I've known about but 'managed' until inspection time.
One of the smaller things was easy to fix.
The horns on the lower rudder which operate the tailwheel steering springs were getting pretty worn where the steel hooks went into the aluminium horns.
The obvious repair was to remove the rudder, dismantle it, take off the horns, weld a blob of weld into the holes, re-dril and they would be good for another forty years/1,350 hours.
Looking more closely, while rudder removal should be fairly easy, getting the horns off looked like a big, fabric-off job, so I chickened out. My inspector had a better idea, quick and easy. Make up a couple of doublers from scraps of aluminium and rivet them in place.
Tools and materials needed:
Two scraps of tough alloy, similar thickness to the original horns, plus another to make a pattern.
Six 3/32 rivets.
Pencil, scissors and card for the initial pattern.
Drill with 3/32 and 4mm bits.
A borrowed rivet squeezer.
Tra-la. Job done.
Yes, the horns will eventually tend to crack along the inboard edge of the doubler, which is why it's underneath, so I can pre-flight inspect for cracks, but the forces are all pretty well along the edge of the plates, with little twisting, so I think cracking is unlikely.
Why not take a look at yours?
Yours, Bob
