July 9, 2014 - In the world of homebuilt aircraft, the annual inspection is that procedure which makes valid the Special Certificate of Airworthiness (CofA). In a sense, meeting that qualification means that you can continue to fly your aircraft. It is also fair to say that your life may depend on it. Typically spring is when annuals are done. As I write this, it is the middle of May.
We are aware that a great many homebuilt owners go to aircraft maintenance engineers (AMEs) to have the inspection done and possibly all the maintenance as well. We find that they are very wise to make this choice. Inspecting your own aircraft is a bit like being your own lawyer at a criminal trial. A man who represents himself is said to have a fool for a client, or so the legal joke goes. In the case of aircraft, it’s not at all funny.
Not too many years ago, we might have wondered why so many builders chose an AME to do their inspections. In fact, some owners rotate AMEs just in case something might be missed by one. It may also be true that each individual has strengths and weaknesses professionally. That is how we got to E class and P class AMEs.
If you have not taken our forum on inspection, you might rather ask yourself what qualifies you to inspect your aircraft.
Recently, the Bakeng Deuce - of which we now own half - was ferried under flight permit to Lancaster Airpark to allow more time to inspect it. For several reasons, we want to have extra time for the inspection. One of those is that this is the first year we have owned the aircraft and we want to be thorough - which means every wire, fastener, and foot of fabric. The necessity of this is in the paragraphs below.
If there are two things that struck us again and again, they are: 1) When you find a defect, stop there and ask yourself what else is wrong. The other is when you find a big snag, it is very tempting to pat yourself on the back and move on. “Surely this is all there is,” one thinks. The opposite is true. Think rather, “What else is wrong?” 2) Resist the temptation to say, “I’ve done enough, or good enough.” Good enough is seldom good enough.
A case in point: The ferry pilot did a very careful preflight, and so should you anytime you fly an aircraft which for any reason has not been recently flown. In this case, the elevator trim was operated full travel, and at that point, it ceased to operate. One of the Nicopress fittings allowed a trim cable to pull out, which means no trim. But it means more than that; if the trim tab is allowed to float free, it is very likely that very serious flutter will occur, and that flutter will cause the elevator and stabilizer to tear off the aircraft. It’s hard to say how one would survive that.
We prefer the pneumatically swaged stainless-steel studs which are swaged right onto the cable rather than the bits and pieces, sheaves, ferrules, and clevis pins which comprise the Nicopress system. This incident tells you why.
Further investigation revealed that the faulty Nicopress fitting was a commercial fitting and not of aircraft grade. It was a much flimsier part. In the world of aviation, a flimsy part is a bogus part. What exactly are your parts sources?
Once the repair was made, the ferry flight was done and the Deuce was positioned to facilitate an inspection.
Editor’s note: Our last series of articles related to the general practice of aircraft inspection. In this seven-article series, the author will apply those principles to a specific aircraft. Future topics will cover how he inspected the Bakeng Deuce, what he found, and how it was fixed. We hope you will find the series useful. Our objective is to keep you flying safely.