Prop Strike

[DOC.400]

My plane is grounded due prop strike with 1500hrs total engine and airframe time. Oh god I'm depressed!!! This is five strikes and three new props in 11 years!! None of which I've been responsible for I hasten to add!!
Insurance job again...Lycoming recommend a complete strip down for internal inspection.
Would you:
a) Claim on insurance, go for strip down, new prop and put back extg unit;
b) Time to put a new engine in (Thank goodness we have an engine fund!);
c) Ignore Lycoming and just put a new prop on, + oil analysis every ten hours;
Answers on a postcard please!!!!!!!

[Saab Dastard]

Doc,

Bad luck - still you aren't missing much flying with all this crappy weather. Saying that, Sunday is supposed to be rather nice.

How much life is left in the engine - when would you expect to have to replace it anyway, prop strikes excepted? What has been done after the previous 4 strikes?

Could you do (a) and go for a re-build to zero time the engine? Would there be much saving over (b)?

BTW, if you choose (c) I will never fly with you again ;)

SD

A little knowledge is a dangerous thing...
A lot of knowledge can be truly devastating!

[Warped Factor]

DOC,

Very sorry to hear that. Just curious to know if it happened at WW?

And if repairs drag on give me a shout if you want to aviate.

WF.

[A and C]

DOC 400 to take a look at the options #1 is part of the answer get what money you can from the insurance and then go for #2 as the engine is not worth putting back together with only 500 left to TBO (dont think of running on condition after 2000 hrs it just costs more in the long run.)
Dont think about #3 as this may not give warning of shock load damage in the wheel case and you dont want the oil pump to stop without warning........do you ?

Having owned DR400 ,s for the last 20 years i,v never had a prop strike and i think to is time your group take a look to see if these problems have a common thread.

[DOC.400]

Thanx for your replies chasps -I am SO depressed! With new prop and engine strip down we're looking at no plane for two months. Interesting comments about increased costs over 2000 hours -I'll take that to the meeting we;'re having, but would like more info A&C -I'll e you direct. Our engineer reckons we should have 900 hours left on this engine easily.....That would take about 5-6 years!!!
There is no pattern to strikes, one was due an uncontrollable shimmy, two stupidity and the rest carelessness and possible unfamiliarity with the plane.
I hasten to add, I've NEVER dinged it and am very aware of the restricted clearance!!!
Somebody take me flying please.......still think of the money I'll save....not.

[AC-DC]

I disagree with A&C regarding the extra costs after the 2000h mark.
My engine is around the 2500h TTSN and about 350h STO. It burns 1l of oil per 6.5h compression is between 74 and 78 on all cylinders. Every 25h I send oil for analysis and change it every 50h or 5 months.
Recently I had to remove 1 cylinder due to broken stud (the exhaust had to be removed), we have removed another one and had a good visual check.
The verdict was that I can keep running it for another 500h.
When the engine will have to come down (2000h or 20,000h) I want it to have new camshaft, new bearings, new pistons and cylinders, etc. I don’t believe in repolished camshafts and other corner cuttings.
Saying that, if I was in your shoes I would go for a new/overhauled engine. Put the insurance money into a good use.

[A and C]

The recomended engine TBO is based on the most economic time to OH.
After the recomended TBO the crankshaft bearing journals start to wear oval and as the crank can move more in the bearing it also wears oval ,the chances are that if the engine is run "on condition" for a long time it will take the crank below the regrind limits and so put up the cost of OH by about 20%.
I have no doubt that some contributors to this forum have got lucky and saved them selfs some money but across the lycoming fleet this will not be the case.