Waypoints

A winter afternoon's sun cast long shadows across the ramp as I walked out of the FBO. The limp windsock seemed to promise a smooth landing to every pilot in the busy traffic pattern. It was a day for flying, but my ride was still in pieces in the maintenance shop. I was frustrated by the thought, but felt satisfied nonetheless. That Saturday I had enjoyed the seven hours spent putting the airplane back together again after its annual inspection — or at least as together again as I could in my unofficial capacity. The pros would be in Monday morning to close the cowling, finish the paperwork, and make it all official. When they finished, N734ZS would be good for another year.

The sign-off would also mark the start of my second year of aircraft ownership. I purchased the 1977 Cessna Skyhawk last year right after its annual inspection, which also served as a prepurchase inspection. That annual was done at a shop at another airport and I didn't participate. In fact, over the past year, I had seen the engine compartment uncowled only once or twice. With a desire to learn more about the 172, I vowed to help out with the next annual.

I scheduled the inspection for late January with a planned February sign-off, to gain an extra month in the cycle. As the date grew near, I carefully made notes about things that I wanted taken care of. I knew of no significant airframe or engine problems, but there were a number of items I was concerned about. As with the engine, the fuel, oil, and vacuum lines were mostly original. And, frankly, I got the willies flying along behind stiff and dried-up hoses that were now of drinking age.

The engine was at TBO when I bought the airplane. Compression and oil consumption are fine, so I'm putting off the engine overhaul until I see signs that it is necessary. Now, though, I can see that I'll be gradually changing out some accessories and parts that would normally be part of an engine exchange — this year the hoses, next year the ignition harness, and so on.

Another item that I had delayed until the annual was the overhaul of the attitude indicator. It had become a bit lazy, waking up slowly after engine start. By the time I taxied to the end of the runway for takeoff, it would be perked up and ready for business. But as I flew an ILS approach to minimums on Thanksgiving weekend, I caught myself thinking how much more challenging the experience would be if that old AI suddenly decided it had given me my money's worth.

A less dramatic item, but more tangible, was a set of new Airtex carpets that the previous owner had purchased but never installed. By installing them I would at least have something to show for the price of the annual.

The appointed day in late January arrived. El Niño was showing its force by spewing wave after wave of cold, heavy rainshowers from the northeast. In its tiedown, the airplane faces west into the prevailing winds. When we get a nor'easter, though, the rain is driven over the airplane from tail to front, always finding its way underneath the wing-root fairings and into the cockpit.

After running head-down through the rain, I dashed under the wing, unlocked the door, and put my hand on the seat to crawl inside. It was soaked — not damp, but quite literally dripping wet. I took off my jacket and threw it on the seat and climbed aboard. Welcome to aircraft ownership.

The normally enthusiastic engine seemed particularly reluctant to start, but it finally caught and I taxied out to a run-up area to warm the engine before the oil change and compression check. My plans for a leisurely preinspection flight were dashed by the low clouds and the promise of ice in them. The oil temp indicator finally moved off the peg, and I taxied to the maintenance hangar.

Once I was inside, John "J.C." Colaluca, director of maintenance at Frederick Aviation, set about uncowling the engine, pointing me in the direction of the wing inspection panels. Six hours later I had removed all of the exterior inspection panels and fairings, taken out the interior and carpet, lifted all of the floor inspection panels, checked the ELT, vacuumed the floor and seats, filled the battery with water, asked a hundred questions, and probably made a general pest of myself with J.C. and Dennis Miller, the other A&P who assisted. Still, I felt far more productive than I do some days at the office, where I become a slave to the telephone and computer.

At the end of the day, I left an oil temperature probe for the J.P. Instruments EDM-700 engine analyzer with Dennis. The shop that installed the analyzer and fuel flow computer last year could not get the engine plug out to install the probe, so I asked Dennis to give it a try.

When I checked in with the shop the next morning, Dennis had wrestled the old plug from its port and installed the probe. The inspection itself was progressing with no major gotchas. The engine compression was fine — all four cylinders in the mid- to upper 70s, well within the acceptable range for the little Lycoming. The exhaust gaskets were worn and in need of replacement and the induction air filter was due to be changed. A broken primer line explained the recalcitrant start the day before. The AI had been removed and shipped out. It turned out that getting an exchange unit was the faster and more cost-effective way to go. I gulped at the $425 charge and later learned that the tight quarters behind the panel cost me another $130 in removal and installation time. All of that and I still need to be proficient at partial-panel approaches!

While things seemed fine mechanically, the paperwork was about to bite me. J.C. reported that he could not find evidence in the logbooks that two important airworthiness directives had been complied with. One, dating back to 1978, dealt with the oil pump impellers. An AD requires that the impellers be inspected to assure that they are not made of a material that was determined to be defective. The second AD dealt with the carburetor floats. It required that any carburetors of certain models installed or overhauled between November 1, 1991, and July 15, 1992, be inspected to assure that the proper type of float was installed.

As it turns out, 4ZS's carb was rebuilt and returned to service on July 7, 1992 — just a week before the end of the effective period — and there was no evidence that the inspection had been performed. "Oh, what's a week among friends and customers?" I asked, hopefully — and with a smile. J.C. lifted an eyebrow and looked up at me over his reading glasses, and I knew I was in for one of those lectures about how A&Ps put their names and, quite literally, their livelihoods on the line with every logbook sign-off, and did I think that he was going to risk all of that so that I could save a few bucks by not ripping apart a perfectly good carburetor. No, of course I didn't think he would do that, but I do enjoy seeing the veins pop out on his neck when he gets up on his soapbox.

So, apart it came. Some $169 in parts and labor later it was together again, the very same floats tucked neatly back in place. One down, one to go.

Ditto with the oil pump AD. Off came the pump. Impellers are OK; on it goes again. This time the item cost $228 in parts and labor. A new set of impellers runs $440, so I guess I should be thankful. Now, though, I have a complete AD list and careful notations that each has been complied with.

I donned my grubby clothes the next day, a Saturday, and with no one around to bother, I set about closing all of the inspection panels inside and out and putting the fairings back in place. My assistant of the day, three-year-old daughter Jenna, handed me tools and saw to it that the inside was properly sprinkled with pretzel crumbs.

I removed shriveled and brittle duct tape from underneath the wing-root fairings — apparently a previous owner's attempt to keep the water out. I replaced it with some new tape, which seems to be helping. The next tactic in keeping the water out is to replace all of the door seals, a job that awaits a warmer day.

Inside, I cleaned the windows and emptied the ashtrays of gum wrappers and lollipop sticks and then set about installing the new carpet. The Airtex pieces fit well, and the job took less time than I anticipated. Next it was a matter of wrestling the seats into place — a job better left to a contortionist.

I left the shop that Saturday afternoon a bit sad that 4ZS wasn't quite ready to join the other aircraft out plying the skies on that warm winter day, but satisfied and confident that it is ready to safely fly another year.