Heal thyself

(ERA09FA093)

By David Jack Kenny

Soaring medical costs notwithstanding, the human body has a remarkable capacity to repair itself when damaged. If aircraft had the same ability, their owners would be wealthier, mechanics would be scarcer, and the GA accident record would be appreciably thinner than it is now. Unfortunately, pilots have been known to overlook the fact that mechanical problems aren’t likely to heal themselves in flight.

Shortly before 4 a.m. on Dec. 18, 2008, a Beech Model 36 Bonanza crashed onto a golf course in Louisville, Ky., killing the solo pilot. He’d departed from Chicago’s Midway Field at about 2:20 a.m. on an instrument flight plan, and was cleared for the GPS approach to Runway 24 at Louisville International about nine miles from the field. Shortly thereafter he declared an emergency due to engine failure and radar contact was lost. Fire crews found the wreckage upside-down on the fairway about two hours later. The right wing had apparently separated after clipping a tree.

The pilot was only 25, but he’d already logged more than 2,300 hours and held an instrument instructor’s certificate. He’d bought the Bonanza the previous July with just 18 hours on the engine since a major overhaul the previous December. He’d had the prop overhauled in August, and flown it a total of 40 hours since taking possession. A few weeks before the accident, though, he’d asked a mechanic at Louisville about an apparent oil-pressure problem. The mechanic advised him to have it checked out thoroughly, especially in view of the recent overhaul. About a week later he’d told the mechanic that the problem had been with the oil filter and now seemed to be okay.

A tear-down inspection quickly found the reason the engine failed. The crankshaft had broken just forward of the No. 2 main bearing journal. The No. 2 bearing journal was scored, indicating that the bearing had been rotating, and the pieces of the bearing itself were in the oil sump. The No. 3 bearing journal also was broken. On the sealing surfaces of the main bearing bosses, the inspectors found a gasket sealant that was not called for by the manufacturer’s overhaul manual.

The night of the accident, the pilot had flown the Bonanza from Louisville to Midway, arriving at about 11:30 p.m. The weather at Midway was good VFR, but Louisville was in IMC all evening, with ceilings gradually coming down from a 1,000-foot overcast and 5 to 6 miles visibility. By the time he climbed aboard for the return flight, the ceiling at Louisville was 600 feet overcast. Visibility was 5 miles in mist and light winds.

According to the lineman on the night shift at Midway, the pilot aborted his first attempt to return home and taxied back to the FBO, reporting “problems with the aircraft.” They put the airplane into a hangar while the pilot tried to find a mechanic, but after learning that no one could get there before morning—apparently aviation maintenance technicians are no more eager to go back to work in the middle of a winter night than anybody else—he had the airplane pulled back out again. It took him three tries to get the engine started, after which he taxied out and took off.

Nothing in the public record explains why he wanted to get home badly enough to risk a flight in nighttime IMC in an airplane with a suspect engine. Whatever the reason, it doesn’t seem good enough. There’s something to be said for staying put until you’ve definitively resolved any suggestion of a problem in a critical aircraft system, and the one engine of a single-engine airplane would seem to qualify. Once you’re sure the problem’s fixed and the time has come to make that test flight, it also makes sense to prepare for the worst by arranging to have everything possible in your favor. Launch in VMC in daylight from the runway that offers the best prospects for an emergency landing. If the wind doesn’t favor it, wait. First and foremost, though, is to gain that assurance that everything really has been put back into good working order. Without it, you don't want to risk launching at all—never mind into instrument conditions at night.

Heal thyself

(ERA09FA093)

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