Annual Anxiety

aircraftmechanicshirts.com

Every airplane owner knows the feeling. You take your airplane to the shop once each year for the inspector to go over it with a fine tooth comb and find everything that is wrong, and try to guess what may go wrong with it in the future.

When your airplane heads in for the annual there is no way to know with certainty how long it will be down, and what the final bill will be. And we are talking potential disaster here. If a significant internal failure is discovered in an engine and it must be overhauled or replaced many airplane owners are staring at a $50,000 bill.

My experience over decades of airplane ownership is that when you have no squawks at annual time, look out. Just when the airplane and all of its systems seem to be working perfectly, the inspector will find some major problems you had no idea existed.

That was my situation for this year’s annual. The airplane was running great. The only maintenance issue I was aware of was a leaking nose gear strut.

A few years earlier I had the shop add Granville Strut Seal to the nose oleo and that bought time sealing the leak to very minor fluid seepage. Granville works to soften and swell the O-rings in the struts to hold the hydraulic oil and nitrogen in. The stuff is widely used in all types of aircraft and it works. If you have a seeping oleo strut ask your shop to add the Granville kit. It’s available from most suppliers like Aircraft Spruce.

But now the fluid leak was back to the point where the nose strut had to be serviced about every six months. The only practical way to disassemble the nose gear strut on a Beech is to remove the whole gear leg. The overhaul parts—O-rings—cost only a few bucks, but labor is going to be several hours for an experienced shop so you’re looking at a $500 tab at best.

The only other actual evidence of a maintenance problem I discovered on the day I opened the hangar door to fly to the shop. There was a fuel stain on the left main landing gear and tire. That hadn’t been there before. The fuel lines run through the wheel well so I hoped it was just a loose fitting. But the two-speed electric fuel pump is also in the well over the main gear. That pump is very expensive to overhaul or replace.

In short order the shop called to confirm my fear. The electric fuel pump was leaking. But, the shop also found a certified repair station that could overhaul the pump for one third the price of an exchange saving more than a thousand bucks. Great.

But in the same call I learned two cylinders were leaking too much around the piston rings to pass inspection. Not exactly a surprise as they had over 2,000 hours on them. Since my flying activity is not what it used to be I’d like to get a couple more years out of that engine so I told the shop to replace them with overhauled cylinders. The engine was running fine, oil consumption was stable and well within limits so nothing bad was going to happen suddenly, but the cylinders were worn beyond limits.

The other “surprises” were some small oil leaks around an alternator gasket and cam cover and seeping case spine bolts and that sort of thing. The inspector also found that my whiskey compass was out of whiskey. I guess I never look at the thing so I hadn’t noticed. Compass fluid has such a distinct smell that you usually smell a leak before it’s visible. But not this time.

There was also a problem with the lower rudder bearing. When the inspector moved the rudder he heard a loud clunk. I had moved the rudder on preflight and heard nothing. But when the fairings were off they could see the bearing had corroded and needed replacement.

As has been the pattern over the past decade or so the annual bill zoomed past five figures. It’s hard to believe so much went wrong in a year and just under 100 hours of flying. If there had been no annual would safety have been compromised? Not immediately. The fuel pump leak was not good because fuel outside the system is at least a small hazard. More importantly, if the pump failed totally I would have been stuck someplace because it is almost impossible to start the engine without the electric pump to prime it. The other repairs and replacements probably wouldn’t have created safety issues for many hours to come and would almost certainly have issued some obvious warning.

But there was one important discovery the shop made and fixed that was a very real threat to the health and safety of me and my passengers. The boarding step mount was cracked badly. The crack was under the edge of the fuselage where I would have needed to lay on my back to see it during a preflight so not a great chance I would have found it on my own.

If that step had given way while I was climbing up to the wingwalk, or even worse, broken when I was stepping down, the result would have been a fall with at least cuts and scrapes, if not broken bones. So, for $195 an immediate safety risk was found and corrected. As for the other many thousands of  bucks, well, rules are rules, and annual anxiety will continue for all airplane owners.

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18 Responses to Annual Anxiety

  1. DEL says:

    Mac, I don’t know how high is that step that cracked, but if you had to lay on your back to discover the crack, that means your fall would have been at most startling. Moreover, a step like that never fails without a warning. Moreover-squared, probably you would have had one leg still on the ground. But cheer up: although that $195 expenditure didn’t really save you from a great fall, and although you were obviously charged too much, at least it didn’t render you broke.

    • Mac says:

      Believe it or not, Del, a foot slipping off the step is a common cause of injury in Bonanzas and Barons. That is especially true when stepping down from the flap. It’s a fairly big distance and if your foot slips off the small oval tred of the step down you go even though you are holding on to a handle with your right hand. Usually the step digs into your shin or leg, but you can also end up in a heap on the ramp. If it sounds like I am speaking from experience, I am. My only icing injury so far. I don’t know of anyone injured by a step breaking, but slipping off is an issue. So watch out when stepping up or down from one of those airplanes if it’s wet or icy or dark.
      Mac Mc

  2. TedK says:

    A wonderfully truthful article that should have a big stamp across it, “Do Not Show to Wives!”

  3. Kim says:

    Mac,
    Just found your blog today courtesy of one of the posts on BeechTalk. How I miss your Flying articles! That mag isn’t the same without you (or Bax, or Richard, or Len) .

    For your boarding step, Guy Ginbey on BeechTalk makes a terrific looking non-slip replacement tread.

  4. Greg says:

    You are probably aware of this Mac, but I just want to say that there is no “hard” standard requiring cylinder work at any particular leakage past the rings. Many believe that 60/80 is a minimum, but Continental does not share that opinion (SB03-3). There are several factors used in judging the serviceability of cylinders, and compression checking is just one of them.

    As I said, you probably are aware, just making sure the reader is aware as well.

    Greg

    • Mac says:

      You’re right, Greg. But these two wouldn’t hold 30 psi using the calibrated orifice. They had reached their limits, but not without thousands of hours of service. I hope nobody is pulling cylinders holding 60, or 50 even. When it drops below 40 time to look for the reason. But don’t pull the cylinder no matter the differential compression until you know for sure what the problem is.
      Mac Mc

  5. Jeff Boatright says:

    You know, Mac, if you built your own plane, almost all of this would go away…

    ;)

    Come on over to the dark side, Mac. We have cookies!

  6. Bill Landry says:

    $500 to reseal a nose gear strut ? I wish I worked for that shop, I could retire sooner with what they pay. Why wasn t the cracked step found on last annual ? Cracks don t happen overnight.

    • Mac says:

      Bill, as expensive as it is to keep airplanes flying it may not be enough to keep our maintenance shops going. I asked the boat yard for an estimate on some painting on my boat. The yard labor rate is $15 higher than what the aircraft shop charged. The boat yard has no certification, no required training, no massive record keeping or other FAA requirements we all deal with in aviation.
      So, a talented young person can work on boats, cars, motorcycles and lots of other technologies and make more money. That’s a problem for our future.
      Mac Mc

      • Jeff says:

        Not really Mac. What the guy doing the work makes and what the boat yard charges are two totally different things. The guy in the Chevy dealership is the one making the money, not the boat or motorcycle mechanic.
        Problem is the hours quoted just don’t add up for most of the jobs. The small aircraft market is very small, where a car shop does it on volume the aircraft shop makes it up on pricing.
        For instance I was quoted $15,000 for an overhaul. I priced all the parts, Under $3,000, so where is the other $12,000.00? Labor should be $2500 to a max of $3500 at shop rates!
        Shop rates already take into consideration insurance, overhead, profit etc.
        Talk about excess profit! If I ran my marine business the same way I would be out of business in a year!

    • DEL says:

      Bill Landry, that crack may have gone undetected for years, because of its hidden location and of being noncritical: a crack on the underside of a step would normally be loaded in compression and consequently propagate barely, if at all, towards complete fracture.

  7. Tom Korzeniowski says:

    While working at AOPA in communications (PR), one of my jobs was to give flights to members of the media. One such flight was in AOPA’s A-36 Beech. The poor news guy exited the plane and slipped on that confounded step, thoroughly gouging his shin. My warning to “watch that step” was about a half-second too late. He was a nice guy, so no repercussions. But I was quicker with the warnings to passengers after that.

  8. DEL says:

    I wonder how much you are usually charged, over there, for a machanic’s man-hour.
    I pay the equivalent of $63 + 18% tax. What do you think?

  9. Stephen Hargis says:

    Annual inspections need to eliminated and replaced with condition inspections like Mike Busch recommends for engine TBO overhauls. There is a higher probability of something going wrong with the airplane just after the annual than if it had been left alone. When was the last time you voluntarily took your car in for an ”annual”? You took it in when you noticed something wrong, like brake noise. Of course, while there your car was inspected and found to need wipers or whatever. You knew that your strut seals needed attention which would be a trigger to take in your airplane for service. This could be done anytime. “Annuals” should be voluntary not mandatory.

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