Das Video dazu ist ebenfalls verfügbar (~4MB): http://www.fly-ul.com/crash/lunsford/CrashVideo.wmv
Bob Comperini wrote:The following crash report, comes from ultralight pilot Marty Lunsford, from North Carolina. Marty suffered injuries as a result of a recent crash. Ironically, he happened to have a video camera mounted on his plane, and running at the time of the crash. I applaud Marty for sharing his story with everyone, and for being candid about "mistakes" he may have made. We can all learn from this.
Marty Lunsford wrote:On Saturday, August 27th 2005 I took my Quicksilver MX to the Raleigh (NC) East airport to do a little flying. On previous flights I had noticed that the engine was only developing about 5700 RPMs at full power. It should be hitting about 6200 RPMs, so a friend of mine, who is familiar with 2 stroke engines and carbs, met me at the airport to see if we could tweak the engine a little.
When I first pulled the plane out of the trailer, I noticed that I had left the fuel valve on after the previous flight. As a result, the air filter was saturated with fuel and oil, and it was even dripping off of the filter. After assembling the plane we tried to start the engine. It normally only takes a few pulls to get the engine going, but this time it took several minutes. We turned off the fuel valve, opened the choke, and opened the throttle to pull lots of air through the engine. Eventually it caught, and we let it run at about 2500 RPMs for a few minutes to warm up.
After the engine had warmed up, we ran it up to mid range, and then full throttle to check the RPMs. It was still only hitting about 5700, so we throttled back to idle and I went to get the Cuyuna manual while my friend held the plane. We looked at the diagram of the carburetor in the book, and after a minute or two, realized that the carb on my plane was slightly different from the carb in my book. Realizing that we weren't going to be able to make any adjustments right then, I decided to just go fly a little.
Here is where the memories of my friend and I break down. We think we had turned the fuel valve at the bottom of the fuel tank back on, but we're not really sure. I had already done my preflight and walkaround, so I didn't check the valve immediately before taxiing out to the runway. The video shows the outcome of the flight.
I was taken away by ambulance, and the next day a couple of friends went back out to the airport to put the wreckage back into the trailer and take it to my house. I asked them to check the fuel valve to see if it was on or off. When they got to the airport, the fuel valve was OFF, but the fuel filter, which is located between the tank and the carb, was full of fuel (it has a clear cover). We don't know how long the engine will run with the valve in the off position, but I suppose it could idle for several minutes, just sipping on the fuel in the carb bowl and the filter.
However, we had the engine running at various power settings for approximately ten minutes before I actually took off. I don't think the engine could possibly run that long if the valve was off, so I'm assuming we turned it back on. But that is one of the "unknowns".
If we had turned the valve back on, then how did it get turned off before my friends picked up the plane the next day? Well, I crashed right next to an airport, and some of the people who came to rescue me were from the airport. It is possible that one of them had enough airplane smarts to realize that the fuel valve being "on" was a safety hazard. Maybe they turned it off shortly after my crash. That would make sense, since the valve was off, but the filter was full of fuel. Of course, all of this is just a guess.
My friends also told me that the prop turned freely, so the engine didn't seize. They tried to start it, but it would not start.
I have also been wondering about the engine kill switch. The previous owner of the plane told me to be careful of it because it was easy to kill the engine when grabbing ahold of the tube by the pilots head. Looking at the video, I clearly did not grab that tube until after the engine died, however, the switch might have some corrosion in it which caused it to short out, or the wire may have gotten pinched somewhere, and the vibration of the engine may have caused it to short out.
It will be several weeks before I have recovered enough to investigate what caused the engine failure. I'll update you when I have more info.
View the video of the crash here. (3.9Mb. ©2005, Marty Lunsford)
Things to notice in the video:
I had 2700 feet of paved runway in front of me, but I chose to make an immediate left turn after taking off. That was my biggest mistake.
When the enginge failed, the plane almost immediately stalled. I was in a turn, and climbing at about 27mph (I remember looking at the ASI). I didn't push the nose over immediately, and since the plane was still at a climb attitude, the airspeed dropped below stall speed in less than a second.
There was very little distance between me and the trees, so even if I had managed to keep the plane from stalling, I still would have ended up in the trees.
It's hard to see on the video, but the plane is spun to the left by the trees. As I fell through the trees, the plane actually ended up going backwards slightly with the wings acting as "parachutes" The camera cuts out a fraction of a second before I hit the ground. If you pause the video on the last frame, you can see the road that I had just passed over. I did a 360 degree turn whle falling vertically through the trees.
Hope ya'll can learn something from this.