March 8, 2018
After leveling off at 9,500 feet, the pilot switched the fuel selector from the right to the left fuel tank. He noticed a change in the sound of the engine, a decline in fuel flow, and a partial loss of engine power. He switched back to the right fuel tank and turned on the auxiliary fuel pump, but this did not correct the problem. Realizing that he would not be able to glide to a nearby airport, the pilot made a forced landing in a plowed field.
Post-accident examination found that the fuel selector had separated just below the selector handle, and the selector valve was found in the 90%-closed position. The fuel selector assembly showed extensive wear. It is likely that the fuel selector separated with the valve in an intermediate position when the pilot changed the fuel selector handle position, which caused a partial loss of engine power due to fuel starvation from the nearly closed fuel valve.
OK, so the next question should be “What caused the ‘extensive wear’ in the fuel selector assembly with less than 350 hours on the airframe?”
I guess a lesson for us all is to never change tanks at low altitude. He had options, so that was good.
All this could have been avoided had he opted for an electrical drive system with good, high capacity batteries…
Going to be accidents as problems on those types of systems are ironed out, though.
As Saint Montgomery (the patron saint of Space Engineers) put it: “The more they overthink the plumbing, the easier it ’tis to stop up the drains….”
Don’t get me wrong…I’d *love* to electrify my Fly Baby. It’s just not the right kind of plane for it. But a one-hour mission duration would match my flying very well (assuming there’s a bit of reserve on that).
Not judging this 2018 accident but it reminds me that I see so many people on forums and even some LSA manufacturers doing sketchy things with primary systems on both certified and uncertified aircraft. Fuel, ignition, flight control, etc systems need to be bulletproof in my opinion anyway and don’t even get me started on 3D printed parts for primary systems being sold at fly marts…
What we’re seeing is what Frank Borman and others have referred to as, “A failure of imagination.” It takes a particular mindset to look at a situation and derive all possible failure modes.
Years ago, one of the members of our club flying Pete Bowers’ original Fly Baby had a rudder cable come disconnected in flight. Steve Jones was one heck of a stick; the rudder cables run on either side of the pilot seat and he just reached down to the free one, and worked the rudder with his left hand.
Post-mortem, it was found that the clevis pin holding the cable to the pedal had come out. The cotter pin holding the clevis pin in place had come free.
Here’s where the failure of imagination comes in: The attachment was set up with the cotter pin on the inside of the assembly…right where the pilot’s feet were. For years flying that airplane, I had noted that my left sock seemed to snag something as I slid my legs into and out of the airplane. In retrospect, it had been snagging that cotter pin…flexing it back and forth until it finally broke, fell out, and eventually allowed the clevis pin to come free. I just didn’t connect that little irritation to the thought that something bad might be happening.
When I reattached the rudder pedal, I turned the clevis pin around so that the cotter pin would no longer snag.
What I found personally irritating (other than a bunch of snagged socks) was that my profession…Space Systems Engineering…was developed, in part, because of the failure of imagination that led to the Apollo 1 fire.I should have connected what was going on.
That’s the reason that most of these “On the Wreckord” articles feature mechanical issues, not just a litany of Pilot Error. Events such as these usually have SOME clue that something’s going on. We just have to learn how to pick up on it.
To paraphrase Captain Malcolm Reynolds: “She’ll tell you she’s hurtin’ a’fore she keens…..”