Comanche Crunches: Maintenance

Our review of the 100 most recent Piper Comanche accidents uncovered something we expected in an aging fleet-a substantial number of accidents due to failure to perform needed maintenance or maintenance that was poorly performed. It showed up in engine failures, 12 gear collapses and an inflight breakup where a badly repaired stabilator came apart.

Particularly impressive was the maintenance malpractice on one Comanche: following replacement of the mixture control cable, the pilot found that the nose gear would not completely extend. Using considerable force on the manual gear extension system, he had it almost down and locked when the engine quit. The cable was so badly routed it was preventing the nose gear from extending, and the pilots action caused the nosewheel to pull the cable to pull the mixture to idle cutoff.

Two pilots found out that when you cant get the gear extended on a Comanche, land on pavement, not grass. Sliding on the turf caused it to ball up and do damage to structural members of the fuselage.

We were pleasantly surprised by the low number of runway loss of control (RLOC) accidents, eight.

We usually see more than 20 for a nosewheel airplane. We think the combination of the wide main landing gear and higher time pilots flying the airplane helped keep the number low. We did note that the other category included at least three overshot landings where the pilot flew final too fast and a couple where the pilots got too slow and stalled or just touched down short of the runway.

Even though we think Comanche pilots tend to be higher time than pilots flying fixed-gear airplanes, there were two student pilots who demonstrated impressive levels of bad judgment. One decided to make a night flight at over 18,000 feet, without oxygen, after taking a combination of meds and alcohol. The airplane hit in a flat spin. The other also tried a night flight and got the airplane into a diving spiral before it broke up.

Icing lead to the inflight breakup of a plane flown by a pilot who friends said didnt like to talk with ATC. In his final trip aloft, he flew in clouds, collecting ice, for some time. He didnt bother to file IFR or speak with anyone. Reconstruction of the radar track indicates he stalled the airplane, lost altitude, then recovered into a dive that he could not control and the airplane broke up.

Icing also caused damage to three Comanches-the pilots were handling the buildup just fine by flying fast on the approach. However, when they began to flare to land they pulled the power to idle. The airplanes stalled and hit so hard that there was structural damage. Lesson: with ice, keep the power on until the wheels are rolling.

Carb ice brought down a surprising five Comanches-Lycomings will develop carburetor ice.

Too fast on landing is not good in a Comanche: one pilot came in at the speed of heat, tried to force the airplane on three times, each time hitting the prop. After touching down the fourth time, he ran off the runway and hit obstructions.

Nine pilots forgot the gear and slid to a stop. The 10th did a touch and go after hitting the prop tips. He then pitched up 45 degrees, stalled and crashed.