Date Question re Service Bulletins

[Half Fast]

This is just curiosity, but I have a question for the POA experts. My recent engine overhaul began in Nov 2024, and we finally finished everything and logged the completion on June 21, 2025. For the overhaul, we used Lycoming SB 240W for the list of mandatory replacement parts.

Lycoming has since superseded that SB with 240AA, which is dated June 24, 2025.

What would have been the ramifications, if any, had we logged my OH completion four days later, on June 25?

 

[flyingron]

Are you operating part 135? Which engine?

 

[bnt83]

Might look at them both and see???

 

[flyingron]

Might look at them both and see???

I suspect he has. The issue is that it sasy "at removal or overhaul" certain parts need to be replaced, the list changed between the two for certain engines, and the notable difference is the requirement that the pistons be changed.

The point of my question is whether the engine was one of the larger ones that this applies to first. Second, unless you're a commercial operator, even "mandatory" service bulletins aren't.

 

[Half Fast]

Are you operating part 135? Which engine?

No, just 91. O-360.

 

[Half Fast]

I suspect he has. The issue is that it sasy "at removal or overhaul" certain parts need to be replaced, the list changed between the two for certain engines, and the notable difference is the requirement that the pistons be changed.

The point of my question is whether the engine was one of the larger ones that this applies to first. Second, unless you're a commercial operator, even "mandatory" service bulletins aren't.

Yes, I know mandatory means discretionary for non-commercial, but the question was aimed at getting caught between dates for a maintenance action that requires many months.

 

[Bell206]

What would have been the ramifications, if any, had we logged my OH completion four days later, on June 25?

What specific ramifications are you referring to?
Does the record entry state the engine was overhauled?
If so, what overhaul reference is given in the entry?

 

[Half Fast]

What specific ramifications are you referring to?
Does the record entry state the engine was overhauled?
If so, what overhaul reference is given in the entry?

The log states, correctly, that the engine was OH'd, but it occurred to me that if we had been a few days later with the entry we might have only been able to log IRAN.

 

[Bell206]

but it occurred to me that if we had been a few days later with the entry we might have only been able to log IRAN.

Not really. You could have simply added an assembly date to the entry or moved back the approval for return to service date to keep those dates separate. But there could be other variables if you had used OEM OH manual vs another FAA acceptable procedure. And technically, there's guidance that states the word "current" in the context of Part 43.13 only applies to documentation that was current at the time the aircraft or engine was produced. So you could have used the manual and SB dated at the time the engine was made and still be legal... but its not something I would recommend in this case. Ironically, for a repair station or a flight manual revision the definition for "current" does mean the latest and greatest version.

 

[bonefishpete]

Service limit overhaul or new limits overhaul? Overhaul is a wide definition.

 

[Bell206]

Service limit overhaul or new limits overhaul? Overhaul is a wide definition.

Yes and no. When you see an average shop advertising a service limit vs new limits overhaul at a difference price point for your average owner its more a play on words given the dimension tolerances allowed on new mfg parts and their associated clearance. Where it does come into play is with custom built or special builds where someone may search through a bucket of parts to find 6 that measure out on the min side of the mfr limit. However, that becomes very labor intensive.

 

[Half Fast]

Not really. You could have simply added an assembly date to the entry or moved back the approval for return to service date to keep those dates separate. But there could be other variables if you had used OEM OH manual vs another FAA acceptable procedure. And technically, there's guidance that states the word "current" in the context of Part 43.13 only applies to documentation that was current at the time the aircraft or engine was produced. So you could have used the manual and SB dated at the time the engine was made and still be legal... but its not something I would recommend in this case. Ironically, for a repair station or a flight manual revision the definition for "current" does mean the latest and greatest version.

Yeah, that’s true, we could have found a way to adjust the dates. In any case, as it turned out we worked to the most current revision. It just struck me how close the dates happened to fall.

 

[WDD]

In any case, as it turned out we worked to the most current revision. It just struck me how close the dates happened to fall.

What if they fell the other way? Say you used a list current in Nov 30 2024 when you tore the engine apart, but instead of June 24, 2025 for the new list, it came out in Dec 1 2024.

What would have been the ramifications, if any, had we logged my OH completion four days later, on June 25?

Whatever ramifications would have occurred if you logged the OH on June 25, one day into the new list, would have also applied to this scenario where you were potentially starting the OH on the last day of the old list.

What determines what list is used? The one current at beginning of OH, or any updated lists that occur prior to return to service?

 

[Silvaire]

What would have been the ramifications, if any, had we logged my OH completion four days later, on June 25?

None, either you are or you are not in compliance with SB-240AA. It doesn't matter what date you say the overhaul was completed.

 

[WDD]

None, either you are or you are not in compliance with SB-240AA. It doesn't matter what date you say the overhaul was completed.

Say I have an engine that has 100 hours on it, overhauled a year ago. Do I and everyone have to pull it and do another overhaul to be in compliance with SB 240AA? Since it's not an AD, the answer is no.

Therefore, being in or out of compliance with SB 240AA is optional?

 

[Bell206]

What determines what list is used? The one current at beginning of OH, or any updated lists that occur prior to return to service?

It basically depends on what reference is being used for the OH. In order to use the word "overhaul" in the mx record entry one must follow the requirements found in Part 43.2 and by extension Part 43.13. So if the reference used is the OEM OH manual they have a note in the front of that manual that states additional Service Bulletins and Service Instructions are considered an integral part of that manual.

And one of them is SB240. So if you record the OH with a general statement "per OH manual on this date" it is implied you used the current revision of those SBs/SIs as of that date... unless you specifically noted using WW vs AA revision. But it only seems to get caught during conformity inspections or accident investigations. If that makes sense.

 

[Half Fast]

And one of them is SB240. So if you record the OH with a general statement "per OH manual on this date" it is implied you used the current revision of those SBs/SIs as of that date

Exactly. Which is what prompted my original post. If necessary, I suppose we could have logged the engine assembly separately on an earlier date to comply with the W rev level, and then logged the engine test run as its own entry, but that wasn't needed. As it is, I have an entry in the engine log that states the OH was done per the Lycoming OH manual (thereby implying the rev of SB240 that was current on that date), but the entry only precedes the revision to SB240 by three days.

Given the length of time necessary to OH an engine, I can easily see someone encountering SB revs while in mid overhaul. From a strict legal standpoint, I think you're okay as long as you state in the log which specific rev you used if it's earlier than the one current with the logbook date.

 

[Silvaire]

...From a strict legal standpoint, I think you're okay as long as you state in the log which specific rev you used if it's earlier than the one current with the logbook date.

Basically you're okay so long as you don't knowingly make a false statement (as in lie) even if you did not make a specific statement as to which SB was referenced. This is why it's not such a good idea to say an annual inspection was performed in accordance with the manufacturer's maintenance manual because in the first pages of some manuals it says to ensure compliance with all service bulletins, instructions, memos and letters. A condition you will rarely find in a privately owned GA aircraft.