Required Inspection or Maintenance Entry for Engine Swap

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Stacheair1
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Required Inspection or Maintenance Entry for Engine Swap

Recently I have been asked the question about swapping engines on two CE-172-P aircraft. One aircraft is a skydiving aircraft (parachute jumping) and the other is used for flight training. The skydiving engine is due for an overhaul and the training aircraft engine has 900-hour since major overhaul. The owner wants to take the engine off the flight training aircraft, install it on the skydiving aircraft, and have the skydiving engine overhauled and installed on the flight training aircraft. Both engines are Lycoming O-320-D2J as called on the Type Certificate Date Sheet (3A12). Being listed on the TCDS would mean this is a maintenance record entry and not a major alteration. However, the question is installing the flight-training engine on the jump aircraft would it require an inspection or would it just require a maintenance record entry per part 43.9. Both aircraft have current Annual inspections signed off. However, the engines and propellers were both signed off as 100-hour inspections during the Annual inspection. If swapping the engine would this nullify the 100-hour inspection on the engine since it is a different serial number? After giving this a lot of thought and searching the Code of Federal Regulations (CFRs) I have come to the collusion that the Annual inspection is still complied with, but the engine that is swapped and install would fall under CFR 49 part 43 sections § 43.15 Additional performance rules for inspections. Reciprocating-engine-powered and single-engine turbojet/turboprop-powered aircraft (12,500 pounds and under) used to carry passengers for hire (e.g., air charter) or used for flight instruction should be inspected within each 100 hours of time in service by an FAA certificated A&P mechanic, an FAA certificated repair station that is appropriately rated or the aircraft manufacturer. An annual inspection should be signed off as airframe annual inspection, engine and propeller as a 100-hour inspection. Since both aircraft are being used for hire, they both are under the 100-hour inspection program. Therefore in accordance with § 43.15 Additional performance rules for inspections before that approval, run the aircraft engine or engines to determine satisfactory performance in accordance with the manufacturer's recommendations of— (i) Power output (static and idle r.p.m.); (ii) Magnetos; (iii) Fuel and oil pressure; and (iv) Cylinder and oil temperature. If all is satisfactory, then a part 43.9 maintenance record entry should be performed indicting the items inspected and approved return the aircraft to service. Under part 91.407 Operation after maintenance, preventive maintenance, rebuilding, or alteration the aircraft does not have to be flown as required by paragraph (b) of this section if, prior to flight, ground tests, inspection, or both show conclusively that the maintenance, preventive maintenance, rebuilding, or alteration has not appreciably changed the flight characteristics or substantially affected the flight operation of the aircraft. However, I would recommend that the aircraft have a flight test and be recorded by a qualified pilot in the Airframe maintenance records for return to service. Some of the items you will may want to include in the maintenance record entry is engine serial number, total time, Airworthiness Directives (ADs) are up to date with the swapped engine serial number and complied with, and the items in part 43.15 noted above. By doing the above, the mechanic will have complied with the following parts: • §91.405 Maintenance required • §91.407 Operation after maintenance, preventive maintenance, rebuilding, or alteration. • §91.409 inspections • §91.417 Maintenance records • § 43.9 Maintenance records • §43.15 Additional performance rules for inspections. Swapping engines on small aircraft is considered maintenance and not one of the required inspections the FAA recognizes. However, this is not to say you cannot perform a 100-hour inspection, but it is not required by rule in this situation. Performing a 100-hour inspection on a swapped engine may be the prudent thing to do, but again it is not required. Keep in mind the aircraft is on a 100-hour inspection program and the engine will receive another 100-hour inspect when the airframe 100-hour inspection is due bringing the airframe and engine back on the same time line for future inspections. At the time of my research I could not find any FAA document that states a swapped engine must have an 100-hour inspection accomplished if swapped.

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JTLARA (not verified)
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Boy, talking about beating a dead horse. Just do a 100 hr. on the engine when you put it in. It's a 172! NO BIG DEAL!

Stacheair1
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I have always accomplished an 100-hour inspection myself just to CYA. But it is good to know that it is not required by regulation. As an IA holder we should know part 43 rules incase this comes up such as in my case with an aircraft out of the U.S. I agree It's a CE-172, but rules are rules.

whitefaced
whitefaced's picture

Stacheair,
I don't believe that FAR 43.15 applies in the scenario you posed. If someone is performing an engine removal and replacement, this is of course "maintenance" by definition (parts replacement), but it is not an inspection. 43.15 only applies when one performs a required inspection. To me, the relevant rule is FAR 43.13.

If one performs maintenance by replacing part(s), that maintenance must be performed IAW accepted methods, techniques and practices as required by 43.13(a). Furthermore, 43.13 (b) requires that the aircraft be in a condition at least equal to its original (or properly altered) condition in areas effecting airworthiness. Both of these rules would make required, additional checks to the aircraft after the new (new to the aircraft) engine was installed. In my opinion, 43.13(b) would also require that the installed part (engine), be in compliance with any applicable AD's or airworthiness limitations, as well as meet its individual type design requirements when installed.

Also, (as you said above) because the engine change (parts replacement) is maintenance, but not in-and-of itself a required inspection, the approval for return to service record entry is required and detailed in FAR 43.9. A signature, certificate type and number are required, as opposed to the certifying "statement" of airworthiness that would be required by FAR 43.11 were this an actual inspection.

In summary, I agree that an inspection is not required in this case. I just disagree on the rule mapping that you used to justify it.

Doug Hereford

Stacheair1
Stacheair1's picture

Hi Doug, you are correct part 43.13 does apply for following the manufactures current maintenance manual and procedures followed up by part 43.9 record entry. The reason I pointed out part 43.15 is engine installation requires some follow on inspections. Such as engine run, mag drop tests and etc. most of these inspections are called out in the manufactures manuals, but not all. The FAA uses part 43.13 as a catch all rule if you will and I agree with that. However, on some makes and model part 43.15 would apply and my whole point is to get mechanic’s to read the requirements of part 43.15 and not overlook it.

Many mechanics will only accomplish what is listed in part 43 Appendix D for inspections and never look at part 43.15 Additional Performance Rules and Inspections. Sections 43.13 and 43.15 do go hand in hand. The whole point is a 100-hour type inspection is NOT required by rule as many mechanics think for engine changes. Thanks for the feedback.

n14ky
n14ky's picture

What the OP doesn't state is the status of the 100 hour inspection on the engine being installed. Since it was removed from a different aircraft, one can only assume that the time since the previous inspection on the engine is no longer aligned with the 100 hour (or annual) on the aircraft it is installed in. The time for the next inspection of the engine is determined by the number of hours of operation on that engine, and if it is due prior to the aircraft, then the engine would require an inspection. To make things simple, I'd do the next 100 hour (or annual) when the airframe or engine came due, whichever comes first.

whitefaced
whitefaced's picture

n14ky,
Could you expand on your post. I have thought about this scenario, and used to think the same way regarding inspection status of individual aircraft parts. I gave special emphasis to TC'd parts like the engine(s) or propeller(s).
As I read 91.409, it seems to me that Annual/100hr. inspections are both "Aircraft" inspections. As I see it, an operator, can R&R any part of the "Aircraft" without disrupting the inspection status of that aircraft.
I guess my rational is: As long as the aircraft is current on its Annual/100hr. inspection, and any parts replacements are done IAW part 43, and the aircraft approved for return to service, then the aircraft is still airworthy until the next "Aircraft" inspection becomes due.
I don't see how it is possible or correct to have inspections out-of-phase (ie airframe, engine, propeller) on aircraft in an Annual/100 hr. inspection program.
Some of the muddiness may come from part 65.85 and 65.87. It is my opinion that one could have as may as five inspectors looking at and signing off a piston twin small aircraft when it is in maintenance for a 100 hr. inspection. This does not presuppose that this inspection could be broken into separate pieces with regard to time in service.

Please comment.

Doug Hereford

n14ky
n14ky's picture

Doug,
This is definitely a grey area. The scope and detail of an annual or 100 hour inspection is defined in Part 43 Appendix D. The only requirement for a 100 hour is if the aircraft is used for the carriage of persons or property for hire provided that aircraft is not covered by another inspection program in 91.409.

I suppose the real question here would be what was done by the installer of the engine to determine the Airworthiness of that engine prior to installation. Does the installer have to perform all the items in 14 CFR43 Appendix D Paragraph d to make an airworthy determination at the conclusion of the installation? As an A&P would you rely on a log book entry from say 99 hours ago that says the engine was airworthy at that time, and install that engine on an airplane that had it's 100 hour inspection done 1 hour ago?

I have done engine swaps in the past, and depending on engine condition and time since last 100 hour, have adjusted the airframe inspection to coincide with the engine if the engine inspection would have come first. I've also done them where I do the entire aircraft inspection at the time of the engine swap. The most common would be doing the engine swap with a fresh overhaul, and you end up inspecting the engine again at the next airframe 100 hour (or annual) even if it is only a couple hours away.

In short, it all depends. Any time I do work I use the advice I used to tell my students at A&P school. "Pretend you are on the witness stand, and the plaintiffs attorney is pointing to the screen with an 8 foot high image of your log entry asking 'what did you mean when you stated . . .?' " and perform the maintenance and records based on what I might have to answer that question.

whitefaced
whitefaced's picture

n14ky,
Thanks for the reply. I could not agree more that this scenario is a bit of a head scratcher. I believe that no matter what parts are changed on an aircraft, the person approving for return to service has the oblilgation to insure airworthiness.
This would be no different if say the part installed were a replacement wing, or other airframe part.
I also agree that we must always put ourselves in a position to justify our actions with reference to airworthiness.
I think the scenario of the installation of the overhauled engine is very common. As we all know, an overhaul does not take the place of a required inspection.
Anyway, thanks for the response.

Doug Hereford

Stacheair1
Stacheair1's picture

This scenario does happen as it happened to me and the mechanic has to be very careful about the record entry and what maintenance steps they accomplish to approve the aircraft for return to service. Part 91 required the 100-hours for aircraft for hire and Annual every 12 calendar months. Installing an engine that is out of phase with the 100-hour inspection could be an issue, but the Annual inspection is still good.

If you look at the Airworthiness certificate, it calls out three parts 21, 43, and 91 to keep the aircraft airworthy. Part 21 type design, part 43 maintenance, and part 91 operational (required inspections). Swapping engines (maintenance) is important and a 100-hour inspection is NOT required, however I completed a complete 100-hour inspection on the aircraft to realign the 100-hour phase inspections with the engine swap and created a new base line even as the airframe still had 50-hours before the 100-hour inspection was required.

The other reason for the 100-hour inspection was to ensure the installed engine was airworthy and we had a new starting point to go forward with. Not all owners would pay for the extra 100-hour inspection, but in my situation, the owner was more than happy to ensure compliance because of his insurance required it as well. The insurance is a main driver in many situations for the owners, this is not a concern for maintainers, but if may void the owner claim if something happens.

As a mechanic legally I could of just performed engine run up, mag drop, power runs and etc. on the ground to ensure engine performance and signed off the maintenance tasks I performed and been legal according to the FAR/CFRs 43.9. However, I like to sleep at night as well knowing that the engine and airframe met all the requirements before approving return to service.

This scenario does happen and as mechanics we need to be talking to the owners and explaining all the reasons why we think it is import to accomplished additional inspections. Because we all know if something happens the FAA will go to the aircraft records and see who and how maintenance was signed off and Monday quarter back.

whitefaced
whitefaced's picture

Stacheair,
My involvement in this discussion is purely a legal one. I think from a practical stand-point, we are each (the three of us) saying the same thing. You, having an enforcement role in the past can surely appreciate both sides.
I perform maintenance for an FAA approved flight school, so in addition to the numerous other visits (part 135 and 145) I receive from the FAA, I have frequent survailence on maintenance acivities related to flight school planes. I have what I consider to be a good relationship with my FSDO.
I have had many similar scenarios with engine changes or other major (what I deem to be critical) parts. The only challenging situations with the FAA, that I have found myself in (14 yrs. in business, and 26 yrs in aviation) relate to issues like this one. That is why, I like to be perfectly clear with my position whenever possible. Fortunately, I have never come up on the wrong side of the issue. I don't anticipate that that result will continue without serious attention paid.
Two other issues I woul like to discuss relate to required signatures, and where maintenance entries are to be placed (which equipment).

Thanks for taking the time to opine.

Doug Hereford

Stacheair1
Stacheair1's picture

Doug, I agree with you we all are saying the same thing and as a former FAA inspector I do look at things a little different now. I have been on both sides of that fence and now I am back as a maintenance person.

I will start another discussion on required signature because it is misunderstood in a lot of cases.

whitefaced
whitefaced's picture

Thanks

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