Waypoints: The owner-hindered annual inspection

Editor in Chief Tom Haines owns a Beechcraft Bonanza A36, hangared in Frederick, Maryland.

The regulations are rather clear about what a pilot who is not a certificated maintenance technician can do to maintain and repair his airplane. Of course, under the watchful eye of an A&P you can do any and all maintenance and repair. I wonder, though, did the writers of those regulations know about me when they drafted those dusty tomes?

My father can fix anything. I’m glad to have him around because the trait skipped my generation. Whether in woodworking, electrical, or plumbing, he can look at any broken thing and find a creative way to fix it. In his retirement years, he has made a successful business repairing antique furniture—pieces usually brought to him in a box. In that box, my father sees the opportunity to craft some new parts and the chance to pass an heirloom to another generation. I see kindling.

So imagine my trepidation when Beechcraft Bonanza expert Adrian Eichhorn called me and suggested we work together to do the annual inspection on my Bonanza. “I’ll frustrate you to no end,” I warned Eichhorn.

“I’m a first officer. You can’t frustrate me,” he quipped. When not tinkering with his immaculately restored V-tail Bonanza, Eichhorn flies right seat for a major airline. He formerly flew N1, the FAA’s Gulfstream business jet, and other government VIP airplanes. He’s also held jobs flying corporate jets for the Washington Redskins and several large companies. An aviation enthusiast almost beyond description, Eichhorn earned his A&P IA a number of years ago so he could work on his own airplanes. Since then he has been an active instructor with the American Bonanza Society and its Air Safety Foundation, a lecturer at aviation events on maintenance, and the developer and seller of various aftermarket lighting upgrades for airplanes through his company, Alpine Aviation LLC.

With Eichhorn properly warned, we tucked my airplane in his hangar on a damp and cold December morning and went to work. I had already removed the aft seats, so once there I removed the pilot seats and lifted the floor boards to allow for access to the gear and flap motor and other systems in the belly. It was clear that the floor boards had not been lifted in the two previous annual inspections since the interior was redone. Hmmmm. During part of the inspection, Eichhorn found a stowaway that paid the ultimate price for its free ride—a mouse, dead in its nest near the spar.

Borrowing Eichhorn’s creeper, I slid underneath the wings and belly to remove inspection panels, actually enjoying myself—happy to be in the company of such an enthusiast who relishes in sharing his knowledge about Bonanzas. Eichhorn went to work on the engine compartment—always the most involved part of an annual inspection. Although there was a lot to do first, we were both anxious to get the spark plugs out so that we could play with Eichhorn’s latest toy, a dental endoscope borrowed from his hangar neighbor, a dentist named Barry Rudolph. Frustrated with the low-tech borescopes typically used by aviation technicians, Eichhorn hit on the idea of using medical scopes to examine the inside of the engine. Eichhorn built a custom workbench on wheels to house the equipment, including a 27-inch high-resolution monitor. “Are you sure you’re not my father’s son?” I asked.

To keep ourselves motivated, we waited to do the borescope inspection until after we had changed the oil and completed a number of other mundane tasks. Eichhorn drained the oil without spilling a drop as I looked on, knowing that I would have coated the floor of his immaculate hangar with at least a quart of the goo. I fumbled with the oil filter cutter, eventually managing to chew it apart to look for any particles. “I don’t see anything with a part number on it,” Eichhorn observed. He pulled a magnet from his carefully arranged toolbox and dragged it around the filter. No metal shavings and only a few pieces of carbon. A good sign.

After jacking up the airplane, Eichhorn pulled off a wheel and placed it carefully on a workbench. He plucked out a wheel bearing and showed me how to clean it and repack it with grease. I worked on the other three, forcing red grease, stiff from the cold, into the bearings. After replacing one set of brake pads, we put the wheels back on and reconnected the brakes.

With the worst of the grunt work behind us and the spark plugs removed and regapped, Eichhorn wheeled the endoscope over near the airplane and plugged it in. He had inspected only a couple of engines since getting the gear, so it was still a matter of trial and error to manipulate the probe through the spark plug holes to get a look around the inside of the engine. But the view was incredible. We could clearly see the cylinder walls, the areas around the spark plug holes—the most likely place for cracks to start, and the intake and exhaust valves. By carefully moving the propeller, we could see the valves open and close and get a look at the valve stems and seats. The good news was that after nearly 800 hours since major overhaul, the big Continental looks sound through and through—an observation further supported when the compression check showed all of the cylinders holding pressures in the mid-70-pound range.

Eichhorn looked over the rest of the engine compartment and found numerous things he didn’t like. None were immediate safety-of-flight items, but they showed a general lack of attention to detail by those who had done work on the airplane previously. The ignition harness wires were not routed properly, causing a few of them to show signs of wear from rubbing against engine parts. Similarly, the heater duct was installed incorrectly so that it was rubbing against another part—wearing a hole in the ducting and inviting carbon monoxide into the cabin if there were an exhaust leak. Eichhorn rewired and generally tidied up everything in the engine compartment.

Eichhorn’s findings in the engine compartment sparked a discussion about maintenance standards today, and the future of light airplane maintenance. Experienced technicians are few and far between these days as A&Ps leave aviation for more lucrative work in automotive and other areas. Fewer and fewer large shops want to work on older airplanes because of liability concerns. The shade tree mechanic may be the only mechanic available in the future—all the more reason that owners get more involved in maintenance. I recommend the owner-assisted annual as a way to get to know your aircraft and your mechanic.

Having not solved the maintenance woes over a cup of Starbucks, Eichhorn produced a list of items that he deferred until we get some parts and then completed the paperwork, signing off the annual inspection on January 1, 2009. I flew the airplane back home that day, grateful for the chance to kick off the new year in the very best way possible.

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