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(quote) .... Many owners and mechanics start getting nervous when an aircraft engine gets to TBO. Although the FAA doesn't require Part 91 operators to overhaul at TBO, countless numbers of healthy engines are euthanized when reach that consecrated number of hours. In this webinar, Mike Busch talks about his own extensive experience operating past TBO that has convinced him that TBO is a concept that is best ignored.

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TBO are somewhat like best before dates ... created by someone to protect their arse not yours and done with a large margin of security again for them

TBO is a recommendation not a limit
Cycle and Time on some accessories are more strict then on the power plant.

Some engines have finite times on some airframes and other airframes the engines do not...TCDS has the limits

hi,

on my 582 I don't accept the 300 hours TBO, I think it is destructive to totally open an engine at 300 hours.

on the other hand I am performing many tests like air leaking tests ( positive and negative) using exhauts lids I have machined and a positive/negative pumps with a pressure gage

I will be doing the TBO at 500 hours which make more sens for me .

opening the crankcase every 300 hours is stupid in my opinion .. it is more dangerous for then engine then to run the engine 200 hours more (3 years for me)

and engine is telling us many things before braking out .

and in the case the engine give bad signs, It has to be opened before it's nominal Tbo

I agree .... if I am curious about engine condition I would remove the plugs and take a look with a bore-scope.

I have known guys who pull the jugs from a Lycoming to check pistons and valves and afterwards complain they have lost a bit of compression and oil consumption has gone up ....

When an engine is broken in and rings are seated the last thing you should do is take it apart because you never get the rings back in the exact same spot they were.

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Don't fix what ain't broken

In Australia, the TBO is the absolute law.... I believe it is 1500 hours they have a minor overhaul (heads off/no crank case splitting) then at 3000 hours, major service (complete overhaul including jugs and pistons... at 4500 hours, throw that motor in the trash... or, what actually happens is they are sold to you guys in the USA, or other countries who don't stick to TBOs.

I have actually heard of planes crashing because their perfectly good motor fails AFTER a TBO. One was a Tiger Moth on a (paid) joyflight over Sydney... the pilot said over the coms to the passenger "Hey! Do you want to stop for a meat pie and a beer?"... the passenger said "sure, why not"... so the plane landed on a football field in the middle of the city.

The passenger got out and said "Where's my pie?" and the pilot said "Sorry, I lied... we just crashed"

The plane had given years (over 70) of good service, but the perfect running motor "had" to be totally dismantled and rebuilt... the replacement oil pump was a dud and failed some 10 hours after the rebuild.

Had the motor not been disturbed by having a compulsory rebuild. it would likely have not failed

Luckily, the pilot was good, he managed to land the plane without damage in the middle of the city.





I agree... it should be "if it aint broke, don't fix it" I mean, compression checks, oil forensics (analysing oil samples), cutting open oil filters, listening for noises, vibration testing, crank run-out measuring wobble at the prop flange and thrust movement by pushing stationary crank in as far as possible, then measuring how far it can be pulled forward... can find out the condition of the bottom end without splitting crank cases for no reason.