The International Cessna^® 170 Association

My C-145 accessory case is held together with nylon locking nuts (AN365). Been this way since rebuild 15 years ago. This year IA thinks they might not be exceptable and should be changed to either AN363 high temp self locing nuts or AN315 with a pal nut to lock it.

I realize nylon nuts are usually not exceptable on the engine or where there is excessive heat but what is exceptable here. The nylon lock nuts have been fine for so long I hate to change them (with out an agrument)at the whim of an IA.

I know George I should have an overhaul manual and parts manual for the C-145. They are on my Christmas list.

Thanks

My parts manual shows a plain washer (PN 2473), lock washer PN (AN936A516), and plain hex nut (PN 2439). The tach drive housing and starter call for elastic stop nuts but almost everything else is hex nut with a plain washer and lock washer.

Thanks. I'm making arrangements for manuals of my very own as we "type".

Any IA or A&P types want to weigh in as to whether they'd change out the elastic stop nuts on the accessory case for a washer, lock nut and plain nut?

Technically the nylocks should not be used on the engine or any hot area. Practically I've seen it done a bunch like on yours that have been there for a long long time and as an IA I wouldn't change them at this point. I wonder if your guy has found all the really important things or if he just has to pick on this to "prove" his knowlege.

Any mechanic should be happy to follow the IPC, which shows plain washer, lock washer, and plain nuts on most locations, and shows elastic AN365's in some locations (which to be correct should be followed.) The generator is another location the elastic nuts are specified by the manual. (By the way, AN365's are not necessarily nylon. Originally they were resin fibre.)

Dave I hear you. He recently found nylocks in another airplane where he didn't expect them but it turned out they came from the factory that way and therefor correct in that application. Now its something he's looking for everywhere. Think I've got to secretly install some blown out nav bulbs and perhaps some thin brakelining for him to find and get his mind off the nylocks.

Right Bruce. Or better yet find a new machanic that will help you keep your plane safe by finding important things.