- Sep 17, 2008
Let me compliment you on your choice of a homebuilt (Bearhawk). Thats one of the benefits of a homebuilt, most everything is new and you don't have to deal with wear and tear creeping up on you from accumulated hours. I'm not knocking Cessnas, they had to be a heck of an airplane to accumulate so many hours...but now that they have accumulated all those hours you have to wonder when they become a liability. As you mentioned, fatigue cracks were found after the airplane was destroyed on the ground by high winds. You have to wonder why those cracks weren't discovered at the last inspection, and how long they had been spreading.
Maybe the wind destruction was a lucky thing after all. I would think that any annual inspection should include thorough inspection of all cables and pulleys not only on Cessnas but even homebuilts.
Excerpt from site below: " If you will notice, the lower bearing for the rudder is made into the bellcrank. It is quite common for the bearing to be extremely worn." Has this been dealt with on the
10,000 hr 150 that was inspected by the nonworking/father A&P and his GA knowledgeable friend? Look at the site and it has some good info. I would think it would be somewhat expensive to
deal with these repairs properly and that deciding when to replace it would be somewhat subjective ($$$).
Cessna 150 rudder inspection and modification.
Cessna publishes Service Bulletins all the time, many of them dealing with issues related to aging airplanes. Fatigue cracks are not unusual, and when Cessna sends out SBs we get serious about them and have a look, and sure enough, we might find exactly what they're talking about. It's no different from old cars with many miles on them. The 172 tends to crack at the bottom of the aft doorposts, where the post meets the gear box. The horizontal stab's forward spar cracks, as we've seen. Some models would crack the forward doorposts at the door lower hinge. The engine mount attach points inside the firewall sometimes crack inside the channel, where it's hard to see. A borescope catches that. The engine mounts of some would crack at the lower transverse tube welds. The mufflers and exhaust risers crack, but that's no different than many other airplanes. The carb air box falls apart. The flap cove skins and their stabilizing brackets in the wings will crack. The flap lower skins crack at the the trailing edges, through the rivet holes. The flap rollers cut the flap support arms and can cause failures. See, there's plenty of information for the serious maintainer. I would not be at all surprised to find fatigue cracks in airplanes maintained by people who don't pay attention to service bulletins.
As far as the 150's lower rudder bearing: there's an SB AND an AD on that regarding the rudder stops. ADs are too often overlooked.