Two prop strikes ?

[procharger]

I am looking at a CTLS that has had 2 prop strikes what should I be looking for 

for damage?

[Roger Lee]

The gearbox should have been sent in to check for internal damage and a warpped prop flange. The crankshaft should have had its run out checked to see if it was tweaked and see if the crankshaft was twisted. All this should have been in the logbook. If it isn't it's just another prime example of sloppy work. If it isn't logged as being done I'd walk away. A fix here would be very expensive.

[procharger]

Gearbox was sent in with no problems. Gearbox inspection was in the log books not sure

about run out yet, will check that out.

[procharger]

How do you check for a twisted crankshaft?

[Anticept]

Line Maintenance Manual 5-50-00 is an entire section on checks following prop strikes. It also references the heavy manual including checking engine out of roundness. Heavy mm 72-00-00 page 4 has the crankshaft check.

[Tom Baker]

Checking the run out is fairly simple. You need a good dial indicator, and it needs to be done while the gearbox is removed.

The crankshaft on the 912 is not a solid piece of metal like most crankshafts. It is pressed together from 5 pieces if I remember correctly. It is not real common, but it can twist where it is pressed together. Here is a preview on the check.

 

[procharger]

Video says without a clutch crank should be inspected, so with a clutch it should be ok??

didn't know any 912 engines may not have a clutch??

[Roger Lee]

All engines before 2003 came without clutches unless you ordered it that way. Then in 2003 Kodiak that imports into the US started ordering all 912ULS engines with clutches. 

Even with a clutch things can be bent and tweaked. The clutch just helps, but it can still happen. Usually depends on prop rpm, type of prop and type of prop strike.

[procharger]

Roger have you ever seen twisted crank from a strike?

[Roger Lee]

Yes. Usually high rpm and the nose into the ground. Just tagging the blade tips on a light at low rpm, no.

[procharger]

Crank and gearbox were checked. Gearbox was sent to lockwood for inspection no 

issues with that either,

[ct9000]

We are probably a bit lucky using Rotax engines. A friend of mine had his Mooney grounded for a full strip and inspect because the mechanic did not like the grass stains on the prop, called it a prop strike. Cost thousands of $$$. At least the Rotax gearbox inspection is easy and not expensive.

[Anticept]

You can get grass stains on a mooney prop operating on a grass strip easy. Those props pull grass up without even touching.

I would have told them to give it a 43.11(b) and found someone else.

[Tom Baker]

30 minutes ago, Anticept said:

You can get grass stains on a mooney prop operating on a grass strip easy. Those props pull grass up without even touching.

I would have told them to give it a 43.11(b) and found someone else.

They are in Australia, not sure our rules apply.

[ct9000]

Tom the problem is that there is a serious shortage of capable mechanics so you are at their mercy. It is not so easy to just "take it some where else".

Also your system allows the operator to make some decisions on what maintenance to have done ours does not.

At least I suspect that we win the flag for the worst general aviation regulator. The US regulator seems to encourage aviation. Our system is hell bent on grounding as many pilots as possible 'cause if no one is flying there will be no accidents. Even traditional flying schools are getting hard to find.

We have gone from about 60,000 current GA pilots to about a quarter of that.

 

[Anticept]

I think you meant to address me. And I was unaware you are an Aussie. Signatures and misc info don't display on mobile.