At some point I started flat rating Beaver annual inspection and standard AD compliance at 150 hours.
These were aircraft that flew about 500 hours during a summer season on floats, some wheel work for bear in the fall and spring. This was a real annual, all the AD’s that might come do during the summer season were performed during the winter annual. There is a lot of disassembly to inspect properly and there is always a lot to correct if you want any bird to make it through a season with a minimum of down time. I would then add hours to the invoice for each non-routine and new AD.
I’ve had some of the best shops and respected mechanics in Anchorage send absolute shit out West, more billable hours for our shop but WTF? Nothing like having to tell a lodge we have to do a spar inspection, fly out a level II NDI guy, or worse on their H stab right in the middle of the season: more billable hours!
The Beaver Maintenance manual inspection runs on a 600 hour/annual cycle with many 100 hour, 300 hour inspections with some odd houred AD’s just to keep everyone honest.
Do get over any idea about bypassing the hundred hour inspections because you are operating part 91.
The 985 manual is an odd duck, its not a FAA approved document,(I might be wrong about this) and for Dog’s sake don’t ever pull it out and show it to your PMI, there are some inspections and TBO numbers that will some day doom the 985 when some pedantic pencil pusher gets a hold of it. As it is the TBO is limited at 1600 hours do to a crank shaft counterweight inspection AD which has proven to be imposable to get past.
FYI: the beaver SRM is also not a FAA approved document, the maintenance and parts books are but not the SRM. So all the handy sheetmetal repairs, fuel tank patches, motor mount repairs, etc are not ‘approved data’, its basically AC43.13 data except where its not.
Some working beaver cheats:
-Aft trim drum, drill a 1/16 hole between the two bearings in the housing and chamfer edge accordingly for a pin greaser tip. You can thank me later for never having a trim freeze up or rust up again.
-fine wire in aft plugs and only use Champion. Take a champion fine wire and a unison and look at the insulator ceramic, that big fat flat nose on the Unison plug is the perfect place for a chunk of lead to sit… I threw the first set I had to pull mid hundred hour into the river. Only pull the aft plugs at 300 hours. Use real anti-seize like that common gray permatex, that black watery stuff that comes with the finger polish applicator is not the right stuff for the job, I’m guessing it was formulated by a liability lawyer? Use a torque wrench for F sake and only a six point socket or six point wrench cut off for a cheater bar cause some F-tard didn’t use the right anti-seize or torque wrench, don’t be afraid to fire up the map gas torch when its gets really stupid.
-Oh ya, we had a few years of odd cracking of cowl and other parts, smoking rivets, took me a while to figure out is was the damn Champion folks cutting some corners causing the internal resistance of the plugs to go up. Plugs would test fine in the bomb tester but at full boost power they would bark. Once the plugs were bad the spark energy would find another path, toast the points, cook the condenser, and then vibration would chaff the leads inside the elbow on top of the magnetos. Cracked spinners too. Once we started testing and tossing plugs it all went away.
My dad says he used old plugs when fishing for Kings on the Sacramento River in California in the late 30’s, said you could walk across the river on them. A lot of valuable resource still left in Alaska and around our world, we are stewards of it all… if we want to keep flying, fishing, and fucking, we had better take care of it.
I told some pilot buddies a couple of days ago that life is like that weight and balance diagram in your TCDS, there is that perfectly safe flying envelope that science, fact, and experience have proven; operate your life accordingly.
Ha ha haha, at the church of Support Systems Aircraft every free lunch comes with a sermon

Rocket