"minor" prop strike question

Engine's are probably 50/50 making it to tbo. Tons of other factors at play. I'd venture a guess and say compression is unrelated to prop strike, but still may be an issue. Get an oil sample. Really depends on what the prop strike was. Hit a bird during taxi is a prop strike, little window cleaner and good to go. Same as leaving the tow bar in. Not going to do airframe damage. How many hours since the strike? 340 hours TT...if it was new after the strike it's 40 hours a year. Can't imagine it being much older than post strike with that few hours on it. If the engine pre dates the strike I'd be more concerned about disuse than the strike.
 
Ernesto Castro said:
The aircraft had a "minor" prop strike on 2013, in the engine logs it shows the entry for the inspection due to the strike, also the prop was replaced. But, in the aircraft log no records appear for this. Does this make sense? I mean, a prop strike not to show up in the aircraft frame logs?
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what did the prop strike? Sometimes these require engine tear down to inspect the crank and internals. This would show in the engine log.
 
What Arob said. In addition, I would add that compression readings are notoriously non-repeatable, i.e., they have a lot of variability. And, 64/80 isn't that bad. However, nowadays any good pre-buy inspection should include a boroscope look inside the cylinders. That will tell you if you have a developing exhaust valve problem causing a drop in compression.
 
The logbooks are there to document the work and inspections that were performed, not necessarily what someone thinks of the airplane or what happened to it. If all the work performed as a result of the prop strike was on the engine then it may make sense for the primary piece of documentation to be located in an engine logbook. What work does the logbook say was performed?

The compression measurements may or may not be concerning. Continental has provided guidance for mechanics to follow to help them determine if the measurement is good or bad, and if the cylinder needs further investigation.

Both these questions (and more) should be discussed with a mechanic that is looking out for your best interest, not the sellers. There isn't enough information provided here to provide any sort of opinion one way or another.
 
I had a prop strike between my a/c and a non-lit taxi light at night that seemed minor. The engine had only about 100 SMOH. The case required welding. My A&P/AI was totally surprised by the cracked case. Make sure the engine had a full tear-down inspection as there is no 'minor' prop strike. The only entries would be in the engine and prop logs, not the aircraft frame logs, unless the cowling was damaged.
 
This is what’s interesting. You can have relatively ‘minor’ prop strikes and do significant amounts of damage and then you can hit an adult sized deer head on like I did and not do any damage at all. These engines are a lot more stout than we give credit for, but it goes to show the value of a tear down and inspect.
 
Ernesto Castro said:
Compressión was always above 70, only the last inspection drop to 64 in two cylinders
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Check to be sure the shop is using the correct orifice size tester…. We had a buyer perform a prebuy inspection on our aircraft and the mechanic used an out of spec/size test device. The result was cylinder compression readings lower than prior tests. The engine manufacture will have a service instruction/document that should provide guidance on this.
 
Arob16 said:
Check to be sure the shop is using the correct orifice size tester…. We had a buyer perform a prebuy inspection on our aircraft and the mechanic used an out of spec/size test device. The result was cylinder compression readings lower than prior tests. The engine manufacture will have a service instruction/document that should provide guidance on this.
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Even if the test fitting in the plug hole is leaking a bit the readings will drop considerably.
 
Ernesto Castro said:
Hey, thanks for all the replies.

To add a little bit more information:

  • The prop strike does appear in both the engine and the prop logbook.
  • The prop logbook is new, as the prop was replaced
  • The engine was replaced with a Factory Remanufactured on 2009.
  • Prop strike was on 2013.
  • The engine was sent back to Continental Service Center for inspection after the prop strike
  • Compressión was always above 70, only the last inspection drop to 64 in two cylinders.
What I get from your comments is that the low compression is not a bad thing and a borescope inspection what shed some light on it.

Thanks!
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It sounds like it was properly handled. Make sure the compressions weren't taken with the engine cold, because those can be misleading.
 
Check the compressions with the engine hot. You will probably find them quite different than the last check. It sounds like the prop strike was properly handled and documented.
 
Dan Thomas said:
If the prop had to be replaced I would not consider it a "minor" strike.
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There is no such thing as a minor strike... even two hits on a cone at close to idle, that didn't scuff the prop at all can actually damage an engine. I know from personal experience with a cone left in front of a plane.
 
RyanShort1 said:
There is no such thing as a minor strike... even two hits on a cone at close to idle, that didn't scuff the prop at all can actually damage an engine. I know from personal experience with a cone left in front of a plane.
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Been there, done that!! I had a cone-strike many years ago. Engine went back to Lycoming and prop went to Hartzell.

Sounds like the prop strike described by the OP was handled correctly, with a teardown inspection at the factory, and a new prop.
 
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