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When things go wrong

 

A Piper Navajo PA31 was on a commercial flight with a planned landing at an airport with which the pilot was not familiar. He studied the Canada Flight Supplement (CFS) and looked for the airport to be on a spit of land jutting out into a marsh land and river. He flew around the area for some time until he found the airport somewhat inland. It was early spring and the water levels were very low.

He was high when he sighted the airport so he reduced power and descended rapidly to complete his landing. He lowered the landing gear on a long final and noticed the light in the handle was red and the gear lights were not illuminated. He looked for the nose gear in the nacelle mirror and did not see it down. He moved the landing gear handle to the up position and then to the down position again. Unfortunately, he did not allow for the landing gear to complete a cycle to the up position before he attempted to lower it again. The pilot decided to overshoot to trouble shoot. Power was added and both engines hesitated and surged causing the aircraft to yaw considerably from side to side.

The pilot then decided to land in spite of landing gear position. He moved both throttles to idle and felt he was using up runway too fast so he moved the mixture levers to the cut off position and then he feathered the propellers. He was unprepared for the sudden reduction in drag with the propellers feathered and the distance he was going to float. He decided to land in the grass beside the runway because it looked like he had more distance free of obstacles to come to a stop.

The aircraft contacted the ground and skipped a few times. One engine dug into the ground and tore the wing which in turn ruptured a fuel line and the aircraft started to burn. The pilot and other crew member exited the aircraft when it came to a stop and luckily sustained only very minor injuries. The aircraft burned up completely.

The pilot had planned to land with VFR fuel reserves. He did not say how long he flew around looking for the airport so we aren’t sure what his fuel state was on final approach. When he finally saw the airport, he reduced power to descend rapidly and later the engines hesitated and surged. When they hesitated and surged, the aircraft was either running out of fuel or the engines had been shock cooled. Since the pilot attempted to overshoot, we can assume (I know what assume means) that it was likely the engines were at a very reduced power setting for too long and had shock cooled. As well, the fire was fuel fed.

Shock cooling is a piston engine problem with which we are all aware, but occasionally forget about when in a hurry. Our choices when we have more altitude than we would like are to slowly reduce the power in increments and descend slowly; or slow the aircraft in level flight, lower the landing gear and flaps and descend more rapidly, but with a power setting high enough to avoid shock cooling.

As soon as the pilot noticed landing gear problem, he should have overshot to a safe altitude to sort out the landing gear problem. With some time available, he would likely have taken more time with the landing gear re-selection. If it had not come down the second time, he could have tried the alternate landing gear extension. With the landing gear up or down, he would have had time to plan the landing. This is assuming that the engines would have responded normally even in an earlier overshoot.

Once the engines started to surge and cause a lot of yaw, the correct decision was made to land regardless of landing gear position. Shutting the engines down was the correct thing to do. The reason we feather the propellers is to reduce drag. The less drag there is the more the aircraft will float in ground effect. The pilot then likely tried to force the aircraft onto the ground, which would explain the skipping. Another possibility is he held it off until it stalled and the skipping was actually a bounce.

It is easy to sit and write or read this and speculate or second guess the pilot and say he could have done this or that. Almost any emergency can be better handled by someone else who has all the time in the world to think about things. I am writing about this accident to start you thinking about emergencies and the things that can go wrong.

The big mistake this pilot made was letting himself get rushed. If we think about the "what ifs" and we plan for them, we are better prepared and are less likely to fall into the trap of allowing ourselves to be rushed.

Fly safely and enjoy the summer.

Accidents are seldom the result of one thing going wrong. They most often result from a combination of things going wrong or from the initial problem not being well handled, which is really one more thing going wrong.

Dale Nielsen is an ex-Armed Forces pilot and aerial photography pilot. He lives in Abbotsford, B.C., and currently flies air charters. He still freelances as a flying instructor and seminar facilitator. Nielsen is also the author of seven flight training manuals published by Canuck West Holdings.

Got an aviation safety story to tell? Dale Nielsen would like to hear from pilots who have educational aviation experiences to relate. Excerpts from these stories will be used in upcoming safety articles. Dale can be contacted via e-mail: dale@flightrainingmanuals.com