It was a while ago, so I don't recall whether I used the stock BVM pipe or had a replacement made.

What I do know is that PRIOR to the incident, I had an original Mk-1 Jetcat P160 in it, and it seized as those motors tended to do. As a result there was a short period of flames shooting out of the back of the motor before everything was bought under control. I'm not a pipe expert, so I took the input from some colleageus at the time, who told me the pipe seemed fine.

It was about 30 or so flights later that I lost the aircraft, so if this earlier incident was the trigger then that shows that your pipe doesn't have to be very obviously hurt from a hot-start / fire ; any slight weakening of the pipe's integrity may not be obvious immediately, and it my take a while for that to grow to the point of a fatal failure. Might be a good idea for a mag article / online feature, for some experts in the field to give us some pointers on how to watch our pipes and assess their continued health.

On the day we lost the Super Bandit, I forgot to take Powermax with me. We hunted around the local stores for some, but could find only pure Butane. A call to Bob Wilcox confimed the Butane should be OK, so we used it. On the starts that day (4 or 5 of them IIRC), there was a momentary deep rumble during each start-up, that went away after a couple of seconds. After scratching our heads a bit, we figured "it's only during the first few seconds when we are on gas rather than kero, so it's probably just a slight difference in the combustion of pure butane vs the regular mix.

In the second last flight, there was a momentary deep growl from the aircraft in the air, and my buddy who was flying the aircraft that day thought he had the onset of flutter so he immediately landed. Checked everything, and all hinges, pushrods, servo gear trains etc were checked and found to be fine. Flew it again, keeping it slower and closer to pay particular attention to noise, behaviour, etc. Part way through the flight, we again got a noise, and this time the pilot said "Now that I can hear it better, that sounds more like a compressor stall" and immediately chose to land it and do some more investigation. But, as he did his upwind turn to set up, he reported "&*** I don't have it", followed by "Actually, I've got everything but elevator" as he shut the motor down and we watched the subsequent creation of a 400+ ft debris field.

From examination of the debris, we could see that the elevator control surfaces, hinges etc were all fine. The servo wires to the elevators were toast. Might have been from one of the momentary two small post-crash fires that we saw at either end of the debirs field, but probably more likely that something went wrong with the pipe, and the wires got exposed to raw temps from the engine and caused the loss of elev control.

Odd thing about the pipe though .... the seams were still intact, there were no holes burned in the pipe walls, etc. The front end of the pipe has two straps attaching it to the bypass and those were still intact and attached to both the pipe and the bypass (though post-crash, the pipe was no longer over the end of the bypass despite still being bolted to it). So, where was the breach ? Best guess is that the pipe must have been able to distort enough to allow the bottom of the pipe to pull off the bypass (which is no easy feat when you see how far the pipe overlaps the bypass in a Super Bandit).

So, although I can not be 100% sure, a pipe collapse still seems the most likely of causes.

My point in typing all of the above up is to let you guys see the possible missed opportunities in preventing this problem. I could / should have gotten a PROFESSIONAL assessment of the pipe (or just have replaced it outright). Despite their best intentions, fellow enthusiasts who are not pipe experts, may not be the best judges of a pipe's condition, and the unusual noises that day (no, not Dave P's gaseous emissions - those aren't UNusual!) may have been warnings that a more someone else would have picked up on.

Gordon