Username Protected wrote:
Sandy, what are the major AD’s on these planes? What are the major problems to look for?
Michael,
Not any onerous AD's on the Aztec. What AD's there are tend to be pretty run of the mill. There's an AD on the F-model stabilators with the "horns" on the tip to check for cracking in multiple areas. I'm pretty sure there is a permanent fix for that, however there is a good reason that Piper went back to the "hornless" design for the last of the F-model run. I believe the airplane flies much better without them...plus the cracking.
As for problem areas I would start with the exhaust and the cowlings. Not the best design for either, and that is being charitable. The cowlings are a two man job to remove/install, and best those two men have some experience too. The stock exhaust routes a lot of heat along the front/bottom section of the cowlings (which are two separate pieces, so times two), requiring fixes which over time can relegate that section of cowling to a patched up disaster. We just overhauled both engines (2250 hours apiece, one was still running perfectly, different subject!) and at that time installed a greatly improved STC exhaust that eliminates that problem area. I don't recall the name of the company, it wasn't cheap but what the heck is on these things? There is also a cowling redesign STC but it is obscenely expensive.
Second area I would pay close attention too is the elevator cable/bellcrank and the elevator trim system. We had some subtle control feel issues on an E-model that turned into a real mess, and it could have become downright dangerous. We ended up replacing pretty much the entire system back there. Speaking of about 4 years ago an F-model (an extremely nice and well maintained F-model) departed my home airport under benign conditions and experienced a failure of the elevator trim cable on initial climb. Only some superior airmanship prevented 5 fatalities. I heard there was talk of an AD but I am not aware of anything further.
The hydraulic control units are one more thing to watch. In general it is a good and reliable system with good backup(s). Our airplane has one pump and I don't worry much about that. We practice pumping gear up and down with the left engine caged here and there... really isn't much too it, especially considering the benign handling characteristics. However if your control unit goes bad there is one quirk to keep in mind, and that is you can't really buy a hydraulic line kit for an Aztec and expect it to just fit. There is a lot of labor that goes into hand trimming every line to fit. So expect that bill on top of the bill to have the control unit overhauled.
Finally I would say that unless you NEED a turbo Aztec to just stick to the N/A version...but I make that recommendation with pretty much all types of piston aircraft.
Hope that helps!
Sandy