AD 50-31-01

[airportbum2]

"Fin removal" for AD 50-31-01, Has anyone dealt with this issue,...any advice? it appears to be very involved.

[8342]

This is a one time AD should have been compliied with by now.
Inspect for cracks. And if none are found reinforcing channels are to be installed.
Check to see if the reinforcing channels have been installed.
If they have been, no further action is required other than the normal inspection during the Annual.
If not, it has not been Airworthy for quite some time.

Rick

[4004]

FWIW from an old timer - what you may find is a doubler repair that was made before the AD was promulgated. Said doubler may not be the exact configuration as per AD -thus, AD was never signed off or signed off as completed. I have not reread the AD in some time - just and ole man memory for a quick response. 1C

[edidin]

The AD specifies "or equivalent" for both options, so an older repair properly documented may be just fine. Presumably whomever returned to service blessed it as equivalent.

[6597]

See if you don't already have the mod done. Also, there is a bulkhead reinforcement that you can see from behind the tail thru that squarish hole for the elevator control cable...

Here's a listing of AD's from the Univair site
https://resources.univair.com/docs/cess ... 170-series

If you are registered on this site you can go to the Resources section on the main website and download Service Letter 57

finpostreinforcementSL57-62A-62B.jpg (261.79 KiB) Viewed 1235 times

[edidin]

Great diagram and pics - thanks!