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Old 07-12-2017, 03:58 PM
guitar dave is online now
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crash post mortem

Motor quit in the air today resulting in the loss of my 36% Pilot SBACH. This plane was powered with a GP 123 using canister exhaust. This was the third season for this plane /motor combo. The motor has been reliable until today when it quit on the fifth flight. Upon post crash inspection I noticed that one header bolt was missing . The header was loose and not sealing on that cylinder. What do you guys think could this cause the motor to quit? I think it may have been the problem. If possible I always want to know what caused the problem to try and prevent future problems. Thanks . Dave.
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Old 07-12-2017, 04:30 PM
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I don't think a loose header bolt would cause your engine to quit.
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Old 07-12-2017, 05:19 PM
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I hammer at 1500 feet
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Guitar Dave, this is a good question. I agree with Terry, probably not likely. If both headers came loose, then you would defitnley lose enough back pressure that motor would quit.

I have seen airplanes that during flight, began to make lots of "new" sound, and upon landing, it was obvious the muffler or header was loose or came undone. I have seen airplanes land with no muffler on at all (guess that guy was lucky).

But you are right, if the header is disconnected, and you are not producing back pressure, and then you got the idle really low, I guess it could have quit, maybe on the top of a hammerhead or something like that. But SO what happened, give us more detail?

Where you 10 feet high and hovering and the motor quit, or were you 300 feet high, and what were you doing when the motor quit?
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Old 07-12-2017, 05:26 PM
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If the header was loose it certainly can cause the motor to quit depending on the needle settings. The tune would be out of whack and would impact the reliability.
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Old 07-12-2017, 05:41 PM
Bill Vargas is offline
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Quote:
Originally Posted by guitar dave View Post
Motor quit in the air today resulting in the loss of my 36% Pilot SBACH. This plane was powered with a GP 123 using canister exhaust. This was the third season for this plane /motor combo. The motor has been reliable until today when it quit on the fifth flight. Upon post crash inspection I noticed that one header bolt was missing . The header was loose and not sealing on that cylinder. What do you guys think could this cause the motor to quit? I think it may have been the problem. If possible I always want to know what caused the problem to try and prevent future problems. Thanks . Dave.
What you described is exactly the cause. Have had these very same issues before,,, loose muffler, loose header, cracked header and all ended with engine quitting at or just above idle throttle stick positions.
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Old 07-12-2017, 05:53 PM
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loose header

When the motor quit I was doing slow rolling harriers so there was lots of throttle blipping going on . The plane was not going very fast so no chance to get back to the runway. It was inverted at the point the motor quit. Dave.
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Old 07-12-2017, 06:51 PM
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I hammer at 1500 feet
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When the motor quit I was doing slow rolling harriers so there was lots of throttle blipping going on . The plane was not going very fast so no chance to get back to the runway. It was inverted at the point the motor quit. Dave.
gotcha.

SO sorry man.

Yes, I agree with Bill. Probably the cause.
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Old 07-13-2017, 05:21 PM
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At least it died doing something you loved
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Old 07-13-2017, 08:21 PM
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reality shift

It is just such a huge reality shift from having a great day at the field to crashed airplane. You guys all know the feeling , one minute you are flying along having a great time then in a matter of a couple of seconds you hear that ominous thumping sound of plane hitting ground which you know will lead nowhere good. I always feel like I want to wake up as if it was a bad dream but of course it is not . Oh well at least we are not actually in our planes when they go down. When I got home after the crash yesterday I told my wife that if I had a bit of The Donald's money I would not even go over to look at the sorry pile of balsa my plane had become. I would just get in the truck and drive home to a big hanger full of ever more planes. Another dream that is not reality for most of us. Dave.
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Old 07-14-2017, 12:23 AM
rooman is offline
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They're get'n lower mate.....
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A bad day at the flying field is far better than a day on the job ....
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Old 07-14-2017, 01:56 AM
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A bad day at the flying field is far better than a day on the job ....
Friendly sentiment... but I'll take a day of work over a bad day at the field anytime.
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Old 07-14-2017, 09:12 AM
rooman is offline
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They're get'n lower mate.....
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Work....that's a four letter word
Beer....that's a four letter word....unfortunately MGD only has three letters
I know which one I prefer - the latter of course
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Old 07-14-2017, 10:55 AM
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Well it may take a few days at work to recover financially from one bad day at the field.
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