New AOC 12yr Engine TBO

[petrickjc]

Looking for information or experience in dealing with TC as a new AO. I have a twin with TSIO-360’s 900 SMOH and 40 STOH six months ago. TC is saying I have. I choice but to do a complete overhaul as the engines are 14years SMOH as a new operator.

[ahramin]

Yep. Hard to get on condition with no history of condition.

[photofly]

The manufacturer's calendar time limit before overhaul (typically 12 years) has exactly the same regulatory significance as the hours-in-operation limits. If your engines are older than 12 years then they are in the same situation as if they exceeded the TBO limit. The (small) upside is that if they're in good condition, the overhaul you're going to have to do on both will be a lot cheaper (in parts) than if they were 2000+ hours.

This is what you need to know about the on-condition program:
https://www.tc.gc.ca/eng/civilaviation/ ... 41-549.htm

[Bede]

Yep. Sad but true.

Best way to run them once overhauled is on condition. Run them until they start making metal or are losing power. You can probably get 2x the overhaul time out of them. By then, most major components (crank, cam) may be beyond repair, but you've still saved a bunch of money compared to overhauling at TBO.

My C150 had 3000 SMOH and was running perfect. I decided to overhaul and now I feel like it was completely unnecessary. Engine runs no better now (actually it ran worse because of a manufacturer's defect in one of the mags).

[petrickjc]

Not looking to go “on-condition” until after the next overhaul to build up the history. Inquiring if it’s possible to get an exemption on the 12yrs and overhaul as per the manufacture once the engines hit TBO of 1800hrs

[photofly]

And I'm not looking for an ice-cream, I just want a desert of frozen emulsified milk, cream, sugar, egg yolk and flavouring materials.

Inquiring if it’s possible to get an exemption on the 12yrs

Yes. It's called an on-condition program! That's exactly what the on condition program is for.

You can get permission for pretty much anything if you can convince the Minister that it's safe for your passengers. In this case the manufacturer says the engine is "done" after twelve years. You're going to have to come up with some pretty stunning technical information about your engines to persuade the minister to ignore the recommendations of the person who designed and built the engine and a half million identical ones.

In any event, go and talk to your Principal Maintenance Inspector. He or she is the person you need to talk to.

[Aero wrench]

There is no need to adhere to the twelve year calendar time as it is a service bulletin. Service bulletins are not mandatory therefore disregard the calendar time. The hard time is used and if you are a new AOC it will take good maintenance and engine shop recommendations to escalate this time. Our AOC has a 172 engine up to 2860 hours and no calendar time. Make sure your maintenance schedules do not include a statement that all manufactures SB's will be complied with.Tell transport to piss up a rope.

[photofly]

There is no need to adhere to the twelve year calendar time as it is a service bulletin. Service bulletins are not mandatory therefore disregard the calendar time. The hard time is used and if you are a new AOC it will take good maintenance and engine shop recommendations to escalate this time. Our AOC has a 172 engine up to 2860 hours and no calendar time. Make sure your maintenance schedules do not include a statement that all manufactures SB's will be complied with.Tell transport to piss up a rope.

As an example, for Lycoming engines, it's actually a Service Instruction, and here it is:
https://www.lycoming.com/sites/default/ ... hedule.pdf

It says :"This Service Instruction identifies the Calendar Time Period in years and the Operating Hour Time Period in hours of engine operation for the Time Between Overhaul (TBO) for certified Lycoming engine models operated and maintained in compliance with all applicable Lycoming Technical Publications and FAA Airworthiness Directives."

As such, it doesn't distinguish between 12 year life, and operating hours life. There's no "need" to adhere to either limit; they're both "advisory" and whether you can exceed either or both of them depends entirely on what Transport tells you.

[Heliian]

There is no need to adhere to the twelve year calendar time as it is a service bulletin. Service bulletins are not mandatory therefore disregard the calendar time. The hard time is used and if you are a new AOC it will take good maintenance and engine shop recommendations to escalate this time. Our AOC has a 172 engine up to 2860 hours and no calendar time. Make sure your maintenance schedules do not include a statement that all manufactures SB's will be complied with.Tell transport to piss up a rope.

Yes, in this case they may not be mandatory but TC is going to have the last word. Telling them to piss up a rope won't get you what you want. Don't forget corrosion inspections and proper preservation practices and tracking of such play into account also.

[Cranium]

As a new operator, you're likely going to be stuck with the manufacturer's recommendations (no matter where they're located).
You may get some relief on the calendar time this time by working with your PMI, but in the future you'll have to go on condition or use teardown reports to get TBO escalations.

Besides, CAR 625 Appendix C just says engines shall be overhauled at intervals recommended by the manufacturer (or per an approved schedule). No mention of hours or calendar time.

[Bulawrench]

As i said previously, the only thing to adhere to is hard time. Write your schedule to reflect that. Then at every overhaul ask for a recommendation letter from the engine shop and if they can attest to the engine being able to go further, you can then apply to escalate the hard time. I don't normally post replies because of the many opinions from the uninformed here but felt the need to offer help. By the way a service letter has even less authority even though it looks official. So if there is a hard time, life limit parts or in the case of the R985 an airworthiness directive that prohibits anything past 1600 hours without slide weight inspection, those are your limits. Your best bet is to work with your PMI. On condition engines are for amateurs and should be avoided at all cost.