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AD 50-31-01

Posted: Wed Jul 26, 2023 5:33 pm
by airportbum2
"Fin removal" for AD 50-31-01, Has anyone dealt with this issue,...any advice? it appears to be very involved.

Re: AD 50-31-01

Posted: Thu Jul 27, 2023 5:00 am
by 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

Re: AD 50-31-01

Posted: Thu Jul 27, 2023 9:52 am
by 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 :)

Re: AD 50-31-01

Posted: Thu Jul 27, 2023 6:22 pm
by 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.

Re: AD 50-31-01

Posted: Thu Jul 27, 2023 7:28 pm
by 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
finpostreinforcementSL57-62A-62B.jpg (261.79 KiB) Viewed 1237 times

Re: AD 50-31-01

Posted: Fri Jul 28, 2023 11:18 am
by edidin
Great diagram and pics - thanks!