PT6 lightining strike

[MtrHedAP]

Does anybody know what pratt n wit says about having a lightining strike on A PT6, well actually on the composite propeller blade. This was on a 1900C. Are their required inspections, overhaul or ? Can you just continue operations if everything seems normal other than the prop?
Thanks

 

[satpak77]

we had one on a B-350, on the blade, and our people told us a teardown was required due to super-heating (the lightning bolt itself) of the various metals inside the engine

don't know the "official" answer, maybe call Pratt directly

 

[ProFracPilot]

PT-6 Powered King Air's are lightning magnets. I've maintained several in the past and all had lightning strikes at one time or another.

It has been a while, but IIRC if you have evidence that lightning passed through the engine then the power section must be removed for a teardown inspection. The evidence will either be visual evidence on the prop - usually on a trailing edge - or by using a magnetometer on the power section to see if magnetism is present. If you find either of these, it is almost a certainty you will also find damage to the planet gears and bearings.

Insurance adjusters HATE lightning strikes on King Air's because they're usually expensive.

 

[erj-145mech]

I had a -41 (#2 position) that took a bolt, and when we got into the power section, several of the reduction gears had gotten magnetized. We didn't go into the gas generator, but we did change the oil and flush the system. We never had any oil related problems thru the next overhaul. The engine had about 750 hrs on it when the event occured.

 

[MtrHedAP]

Thanks guys. I understand more about what can happen internally now. So if i understand correctly all that need worry about is the power section? I guess we will see what happens. I am flying now and just want to make sure maint does the correct procedures.

 

[avbug]

It's not just the power section. You may have shaft issues, and generally the engine and parts will need to be degaussed. I've had several strikes on PT6's with Hartzell props and the props had to be torn down and sent out, too. In a few cases they had holes burned in them.

 

[MtrHedAP]

Ok, all I know maint did was swap props, check for magnetism, check oil screens / chip detector and will do the same in 25 hours. Airplane is back flying. We are operating in africa with south african engineers so just want to make sure nothing shady happens or cut corners. Realy dont want it to quit at gross weight, high temp and short dirt strips. On two engines its hairy enough.

 

[414Flyer]

PT-6 Powered King Air's are lightning magnets. I've maintained several in the past and all had lightning strikes at one time or another.

Have had 2 strikes in Cheyenne IIs myself. One in west Africa, one over India.

 

[Torqued]

Looks like you don't trust maintenance very much. Is there a specific rreason you think they will do something to cut corners? From what you've said they've done, it sounds like they've followed Pratts procedures. In our books it calls for a prop teardown and a check for magnetism of the prop shaft. If the magnetism is too high then a power section teardown is called for.
If you don't have a clue what they are supposed to do then how do you expect to make sure they don't do anything shady?

 

[MtrHedAP]

Torqued,

Let me start off and say that I am an A&P with IA and that my 5 years experience in maint has been in general aviation and have no turbine experience. I trust maintenance very much as i know how difficult it can be and the standards that mechanics are held to, but here in Africa it is "different". My worries were if they had taken the correct actions concerning the lightining strike. The reason is that originally i heard they were going to tear down the engine. Also this group of engineers has not impressed me very much in the past, mostly paperwork, recordkeeping, and MEL's. I have admitted i didn't have a clue what was supposed to be done as i dont have access to manuals, and maint seems to treat the pilots as a disease. For that fact i have started this thread to find out what others experiences were and what they did.