What Happened Here? (Engine Monitor Puzzler for June)

[Mike Busch]

SavvyAnalysis has started a monthly newsletter for folks with SavvyAnalysis accounts (both Free and Pro), and it includes a monthly "puzzler" where we present some "interesting" engine monitor data and then challenge you to figure out what happened. Here's the puzzler for the June issue:

https://www.savvyanalysis.com/flight...5-392a223c16f5

Some hints: This is a turbo with a MAP red-line at 35.5". The entire flight lasts only 11 minutes. After an uneventful pre-fligh runup, the pilot applies takeoff power (at approximately 6 minutes into the data) and very bad things happen. (The engine is being replaced.)

Once you think you've figured out what happened (or you give up), you can read my detailed analysis here:

https://www.savvyanalysis.com/newsle...013-05/puzzler

But please try to figure it out for yourself first. That's the whole point.

We're going to try to do one of these every month.

BTW, if you'd like to receive the monthly newsletter -- which includes a monthly article by me about engine monitor data analysis, tips and tricks for using the SavvyAnalysis site to analyze your data, and the monthly puzzler -- just sign up for a free account at SavvyAnalysis.com and you'll automatically be on the list. Each newsletter includes an unsubscribe link in case you change your mind.

Enjoy!

[vaflier]

Mike, excellent educational tool. Thanks for taking the time to try and teach the rest of us a bit to help us care for our aircraft.

Randy

[Mike Busch]

Mike, excellent educational tool. Thanks for taking the time to try and teach the rest of us a bit to help us care for our aircraft.

Thanks for the kind words, Randy.

[cub builder]

Mike, that's an interesting case. An engine where everything is right, except everything quickly goes wrong. I was puzzled until I read the answer as the cause was not apparent in the data. I'll look forward to your next puzzler.

-CubBuilder

[Bill Greenwood]

I know of a similar case years ago.
Lefty Gardner stopped at the Eagle airport in his P-38 White Lightning, with turbocharged Allison engines. He asked to be fueled, but was not there at the plane, think he was inside or getting a bite.
The taxi out and run up was normal, but upon adding takeoff power the engine was rough.
Lefty was good enough and quick enough to sense it and abort the takeoff.
The only engine damage was to the spark plugs, not to piston tops or valves.
He gave me one one the plugs, and it looked like someone had hammered it with a pick axe on the firing end.

Turns out the line boy had never seen a P-38, never heard of an Allison, but it was a pretty big high performance plane, so he put jet fuel in it like all the corporate planes that stopped there. I am not sure if the word "Turbo" was anywhere on the cowlings or not.
Anyway Lefty always supervised his fueling after that.
Another way is to check your receipt to see what was put in, and of course it is a good idea to have the fuel caps labeled as to what fuel is to be used.