On condition

[rhtrudder]

Wondering what’s involved in flying with a engine that has passed TBO, 914 engine in my plane has got 200 hours left , compression hasn’t changed , no more oil consumption, have flown it from 400 hrs to nearly 1800 , $45000.00 to replace it 

[Flightrite]

I heard a new 915 is just short of $60K! Ouch!

An engine doesn’t know it’s close to TBO, don’t mention it to the donk and keep flying😉

[rhtrudder]

Wondering where I stand legally 

[turboplanner]

5 minutes ago, rhtrudder said:

Wondering where I stand legally 

Ask a specialist Public Liability lawyer; they would be the ones suing you if a duty of care applied and something went wrong, so the best to answer the question and give you the correct answer. You should so some reasearch  before you go, e.g. What is the CASA definition of "On Condition", "TBO", etc. and other relevant facts.

[Thruster88]

There is an article about this in Australian Sport Pilot #102. If the aircraft is an LSA registered with RAAus the answer seems to be no you cannot run on condition. Registration as an experimental is suggested.  In VH land a high percentage of aircraft including those involved in air work, (flying training) are on condition, go figure. 

[skippydiesel]

Rotax 9 engines had operational hours and calendar time to TBO. 

 

My last Rotax 9  (in a 19 aircraft) had 920 hrs operational time out of (if memory serves) 1500 hrs and had long passed they 10 years calendar time it started with - so we had passed TBO a long way back. Engine running like the preverbal sowing machine, leak down tests all good, nil oil consumption between services.

 

3 hours ago, rhtrudder said:

Wondering what’s involved in flying with a engine that has passed TBO, 914 engine in my plane has got 200 hours left , compression hasn’t changed , no more oil consumption, have flown it from 400 hrs to nearly 1800 , $45000.00 to replace it 

Does not the aircraft category (19 or 24) have a bearing on this?

 

I think 19's can pretty much go as long as the owner wants its to go

 

24"s , that go over TBO, will loose their training/hire privates and may not be supported by the factory.

[Garfly]

Section 12.6 of the RAAus Tech Manual sets out the official position on all that.

 

 

https://members.raa.asn.au/storage/raaus-technical-manual-issue-41.pdf

 

This is the first page of the section.  (Click to expand)

 

[ClintonB]

I recently purchased Mike Busch book called on engines, it has been a real interesting read so far. His personal aircraft ( a twin) was happily run to 3300 hrs per side, with lots of bore scope and non invasive inspections along the way due to TBO’s listed at 1500. His operation of the engines was a lot different than what is taught, LOP versus ROP being taught as the correct way to run for longevity. Recommendations on using CHT’s on all cylinders instead of EGT on one, which he explains does not tell us enough about the true operations.

I will be asking my LAME to have a look and might put CHT monitors on all cylinders. On the hottest day I still never seem to get out of low green on all the factory car style 60 year old gauges.

I don’t really have the funds to spend 60k plus on a rebuild for an O 470 in another year or two.

[440032]

CASA does have "on condition" info in AWB 02-01 On-Condition Maintenance.

Targeted at the VH world of course.

[Yenn]

Clinton. To get the best out of your engine you need EGT on all cylinders as well as CHT. It may seem like an excess cost to install, but having all that info enables you to diagnose problems easily. For example I have had a Lycoming misfire after a long taxi, when I hadn't leaned enough. I could immediately tell which cylinder and also which plug was misfiring by checking the gauges.

Lycoming don't like lean of peak running and in some cases their recommended procedures can be detrimental to engine long life, such as their recommending running just rich of peak in cruise.

[facthunter]

Idle is often very rich and if you are experienced you can lean the idle to stop plug fouling, but you need a procedure to avoid forgetting to go normal for take-off. I'd stick to the manufacturer's recommendations. Lean makes the fuel octane rating lower and more prone to detonation and has an oxidising effect on engine parts and oil film on cylinder walls. Take off power is richer than normal for a reason. Reduced power take offs makes engines less reliable without the extra protection of the richer mixture.. EVEN fuel mixture distribution is important., The mechanical injection with GAMI injectors is excellent in that respect.  Nev 

[spacesailor]

On automobiles  it,s actually illegal to tweek the computer, for leaning the ' none power ' times on the newer engines.

It gets rid of the black tail pipe. ( FUEL USED TO COOL THE MOTOR  ).

I have a friend who got caught. BUT he proved it worked good on his V6.

spacesailor

[Yenn]

If you lean while taxying, enough to keep the plugs from fouling you will not get anywhere near full power at take off and it will be immediately apparent. Not much chance of taking off too lean, but you need to be monitoring those EGT numbers. Problem is a lot of pilots do not understand EGT and CHT and the differences between them.

From memory Mike Busch's book explains it all.

[Flightrite]

I don’t know how I ever got thru flying a zillion hours behind old Conty’s & Lyc’s with barely an oil pressure gauge!😂

[pmccarthy]

Oil pressure gauge? We were lucky to have an engine at all. 😁

[Garfly]

Right ... any excuse for another look, then ...  Oh, aye!      ;- )

 

 

[Thruster88]

On 18/04/2022 at 3:17 PM, Flightrite said:

I don’t know how I ever got thru flying a zillion hours behind old Conty’s & Lyc’s with barely an oil pressure gauge!😂

All my '63 Musketeer has is a line in the POH that states cooling has been demonstrated for a 106°F day. Seems to be working just fine so far.🤔🤗🤗