FAA response to mandatory maintenance intervals

[sword_guy]

This letter from the FAA is pretty clear.

[FlyingMonkey]

The engine TBO aspect is misleading.  No certified aircraft not used in commercial work loses airworthiness for operating an engine past TBO, and I don't believe an S-LSA does either.  

 

Since the letter only references TBOs and life limits of components specified by the aircraft manufacturer, I'd say that unless the aircraft's maintenance manual specifies engine overhaul at a specific interval, then the owner is fine running the engine past TBO.  Rotax might have a TBO on the engine, but if it's not specified by the aircraft manufacturer as a life limit, it's really just a suggestion.

[Roger Lee]

Hi Andy,

 

I believe you are correct. You are bound by the aircraft MFG manual (not the Rotax manual) that came with your plane at the time of it's airworthy certification issuance.  Like my manual it has no direction to do an overhaul at the engine TBO. I could be wrong, but I don't think any CT manual has that specific direction. If it doesn't then on condition inspections would be allowed.

[Tom Baker]

Doesn't this seem to differ from some of the FAA's earlier interpretations?

[gbigs]

The letter clarifies a term, it is not an interpretation of the reg.   An A/C cannot be 'rendered invalid' instead is 'rendered ineffective.'  The result makes the A/C 'neither appropriate or nor current.'  

 

Maintenance on the aircraft must be done in accordance with 14 CFR parts 43 and 91 otherwise the A/C becomes ineffective and the aircraft cannot be operated or the FAA will subject the operator to an enforcement action.

[FlyingMonkey]

The letter clarifies a term, it is not an interpretation of the reg.   An A/C cannot be 'rendered ineffective' instead is 'rendered invalid.'  The result makes the A/C 'neither appropriate or nor current.'  

 

 

Of course it can.  If you don't do an annual, your airworthiness cert is ineffective, but not invalid.  Once you get the annual, the cert is once again in effect.

 

It's probably much less common for a cert to be invalidated.  Probably only happens if the FAA finds out there was fraud or malfeasance in original cert issuance.

[CTCTPilot]

The engine TBO aspect is misleading.  No certified aircraft not used in commercial work loses airworthiness for operating an engine past TBO, and I don't believe an S-LSA does either.  

 

Since the letter only references TBOs and life limits of components specified by the aircraft manufacturer, I'd say that unless the aircraft's maintenance manual specifies engine overhaul at a specific interval, then the owner is fine running the engine past TBO.  Rotax might have a TBO on the engine, but if it's not specified by the aircraft manufacturer as a life limit, it's really just a suggestion.

 

You are certainly correct that Lycoming and Continental engines are often run beyond manufacturer's recommended TBO; however, the intent of the questions answered in the letter at the top of this thread was to address specifically the differences between S-LSA certificated airplanes and certificated aircraft because there are a number of components (including the Rotax engine) which have mandatory replacement intervals specified in the maintenance manual for the component as opposed to the TBO being a manufacturer's recommendation.

 

This being said, you are not correct in your assertion that "the letter only references TBOs and life limits of components specified by the aircraft manufacturer." (emphasis added). The subject line of the FAA's letter above indicates that it includes components' maintenance manuals. They can affect airworthiness also when the aircraft manufacturer is silent on the issue of maintenance for a component (the engine for example). The subject line is:

 

"Guidance Regarding Failure to Perform Maintenance Deemed Mandatory by Manufacturers of Aircraft or Aircraft Components and/or Systems Installed on Aircraft Issued Special Light-Sport (S-LSA) Airworthiness Certificates" (emphasis added).

 

Further, on page 2 of the letter, the FAA wrote: "An aircraft that is operated after components have exceeded life limits specified in the manufacturer's maintenance manual...would not comply with [FAR 21.181]." In this sentence, "manufacturer's maintenance manual" can refer to the manufacturer of the component, and is not limited to the maintenance manual of the airplane.

 

The second paragraph on page 2 continues: "You presented the following facts in a hypothetical: (1) schedules for overhaul or replacement of components were disregarded, (2) a component or system has exceeded a life limit specified in a manufacturer's maintenance manual..." Again, since the manufacturer of the airplane itself does not provide guidance about when the engine should be maintained, the engine manufacturer's maintenance manual controls for engine TBO requirements and other maintenance.

 

Ultimately, the above is my opinion about the letter, and I am not an attorney. I would be very hesitant to operate a S-LSA aircraft beyond any TBO or replacement schedule deemed mandatory by the maintenance manual of that affected component's manufacturer. I say this because the following is the first 2 paragraphs of the letter sent to the FAA that generated the above response:

 

"I am writing to seek resolution to the unanswered question as to the extent of the impropriety of failure to perform maintenance deemed mandatory by manufacturers of aircraft or aircraft systems installed on aircraft issued Special Light Sport Aircraft (S-LSA) airworthiness certificates.

"Specifically, and as an example, Rotax engines are common in airplanes certificated as S-LSA airplanes The engine manufacturer’s maintenance manual, the “BPR-Powertrain Maintenance Manual” (hereafter the “Maintenance Manual”) specifies mandatory replacement of life-limited components such as rubber coolant and fuel hoses after five (5) years (Chapter 05-10-00, Page 8). The Maintenance Manual also requires the overhaul of the entire engine at the earliest of either a specified number of hours of use, known as a Time Before Overhaul (TBO) or after a specified number of years, as determined by engine model (Chapter 05-10-00, Page 5)."

 

Therefore, it is quite clear that the FAA understood that they were being asked to speak specifically to the issue of the Rotax engine when they generated the response being discussed in this thread.

[FredG]

I agree that the phrase "Manufacturers of Aircraft or Aircraft Components and/or Systems" suggests that compliance with Rotax required maintenance is necessary for continuity of S-LSA airworthiness.  It also suggests that running beyond TBO may result in loss of airworthiness.  Yes, that would be different than the certificated world.  

 

I am not a lawyer and I am not offering legal advice nor am I offering aircraft maintenance advice.  Regardless, I am reading what is written and it seems to say that failure to do everything that Rotax (and FD) requires, on the Rotax (and FD) schedule (e.g., 5 year hose replacement) makes the airplane un-airworthy.  

[gbigs]

Flight Design is the manufacturer of the aircraft and their maintenance directives apply in regard to regulations.   All Flight Design maintenance requirements are listed in the Maintenance And Inspections Procedures Manual and the supplement Airplane Maintenance Manual. 

 

The FD Maintenance manuals detail all maintenance and logging requirements, inspections  and  instructs owners to abide by the Rotax Engine maintenance manuals for their engine.

 

Thus, ANY and ALL maintenance requirements from Rotax for the engine applies.  The same goes for all other equipment made by other makers, such as Garmin, Dynon etc.

 

 

Maintenance & Inspection Man.pdf

Airplane Maintenance Man.pdf

[Roger Lee]

"Thus, ANY and ALL maintenance requirements from Rotax for the engine applies."

 

Not if it supersedes the FAA regs that are already in place. Rotax can not dictate or supersede FAA regulation.

Just like a Rotax SB that says mandatory. Legally in the US it isn't mandatory unless it is published an SD.

 

 

An aircraft MFG like FD, Vans or SportCruiser, ect... or Rotax can not write regulations that supersede the FAA regulations. The FAA allows you under certain circumstance to go on condition past TBO. I researched this with the FAA a couple of years ago. The FAA has some regs that are minimums only and in that case an SLSA MFG can more stringent, but in other cases the FAA regulation is hard and fast and the SLSA can not supersede that authority with more stringent requirements.

 

Since they are already closed it looks like it's time to call the FAA in person tomorrow.

[Roger Lee]

I talked to a few at the FAA LSA division this morning. The one person that they all referred to is out of the office until July 20. I'll call back then.

 

They did however say that LSA is no different than certified as far as TBO requirements.

Cont. and Lycoming have TBO's and so long as you are not under part 135 you can go on condition after a TBO and are not required to do a TBO overhaul and it does not affect the airworthy certificate. That no one can require anything above what the FAA already has in place. So long as you are compliant with part 91 you should be good to go.

Under the second question second page the term "exceeds life limits". Rotax doesn't have a life limit where a part needs to be discarded. It has an on condition inspection where a part may need to fall within a certain minimum and maximum limit, but that is for all engines in the aircraft world. So long as all parts fall within Rotax's specified wear limits then they can be used indefinitely until they no longer meet the max or min. limit. On Condition.

(As an example helicopters have some life limited parts and no matter what at certain time intervals parts must be discarded.) 

 

 

This said I will call the FAA back July 20 for a more concrete answer. I'll report back after the 20th.

[sword_guy]

"Rotax doesn't have a life limit where a part needs to be discarded."

 

Please see attachment...time limits.pdf

[Anticept]

I've always said that it is the airworthiness limitations section that dictates life limits on parts, and the FAA are the only ones who can approve such section. They don't approve any LSA sections. However, this legal interp doesn't say anything about it. It actually goes and plops everything right in the manufacturer's hands.

[sword_guy]

That's correct.  When LSA was created, the FAA wanted little to do with it, so they left it to ASTM standards and manufacturer requirements.  The FAA basically gave LSA manufacturers full authority on the requirements for maintenance and continued airworthiness (so long as it didn't supercede the FAA requirements).  The FAA does not have specific requirements for LSA maintenance and life limited parts, so it falls on the manufacturer.  But when Rotax said special training was required, the FAA stepped in and said they couldn't do that.  These are two separate issues, and comparing them would be like...well you know.  Apples and oranges...

[Roger Lee]

Hi Sword Guy,

 

Those are only a few rubber components and not the TBO. It's the TBO overhaul in question. If you look in the Heavy Maint. manual you'll see most of the limits used for component replacement or continued use. The component replacement (5 year rubber) isn't legally enforceable either. The FAA told me years ago it is highly recommended, but not enforceable legally. I'll ask again this Monday when I talk to them. We discussed this with the FAA 3 years ago. An overhaul manual is not accessible to anyone except the service centers like CPS, Lockwood and Leading Edge.

 

"The FAA basically gave LSA manufacturers full authority on the requirements for maintenance and continued airworthiness (so long as it didn't supercede the FAA requirements)."

 

This is partially correct. The aircraft MFG has some leeway in some areas, but no LSA MFG can supercede anything what the FAA has in writing. They can't be more stringent or give away the farm.

Anything an MFG does must fall within the FAA regs. 

As an example: If the FAA says you are allowed to go on condition for an engine at TBO and aircraft MFG can not legally require one.

or

If the FAA says someone can not do the work on a certain aircraft that company can not authorise someone to do maint. if the FAA says they can not.

 

 

 

 

An MFG can write things in manuals, but some are not enforceable. Then It also depends on which manual they write it in,  i.e. POH or maint. manual and a 2006 POH and or maint. manual may be different than a 2015. You get to follow the one that was issued at the time of your aircraft airworthy cert. unless the aircraft MFG publishes a document that says a certain manual now supercedes all others, but that hasn't happened with FD and won't because of the different components and designs of aircraft since 2004.

[Anticept]

It should be mentioned that there is a big disconnect regarding S-LSA between those that wrote the reg (OK city) and those who interpret the reg (Wash DC). Will be interesting to see how things play out.

[gbigs]

Roger.  the Rotax bulletin is very clear.

 

The engine MUST be taken out, cleaned and returned to Rotax at TBO.

 

Each 5 years these MUST be REPLACED:

- venting hose carbs

- all rubber hoses cooling system

- all rubber and Teflon hoses in fuel system

- all rubber hoses of lube system

- carb sockets

- connecting hoses of air intake

- diaphragm of both carbs

- rubber hoses on compensating tube

- V-belt

- fuel pump

- coolant replacement

[Anticept]

100: Lycoming and Continental have those bulletins too. The FAA will not accept making these bulletins as part of an AD or an airworthiness limitation (thereby, would have made them a legally enforceable time limited part) unless the manufacturer can prove that on-condition field inspections are not enough for use in part 91 ops. Some propellers, some engine parts, and even some aircraft parts ARE enforced using ADs and airworthiness limitations as there has been proof provided that those parts and props become hazardous and unpredictable after a certain life.

 

We're trying to get the same treatment for Rotax engines. So far, history has shown that field inspections are more than enough, and that enforcing the TBO would amount to an infinitesimal change in safety, yet is a significant financial burden. The biggest thing I think is BS is the 10-15 year TBO limit (depending on S/N), followed by the hoses (use a different hose if confidence in them is only 5 years, this is ridiculous).

 

Unfortunately, the general thought of aviation in Europe is a lot of scrutiny and mistrust VS the trust in aviation here in the USA. A lot of "Mommy knows best" goes on over there, and in some cases it's for good reason. Still, in aviation abroad, it's really bad, with rules being written explicitly stating what you can do, while in the US, it's more of a "you can do anything as long as it's not x, y, and z".

[Roger Lee]

"Roger.  the Rotax bulletin is very clear."

 

Except Rotax can not make rules as they are only a component of the aircraft MFG and the aircraft MFG must test all components and certify the entire aircraft before it can get a certificate. So only the aircraft MFG can make rules and then only up to what the FAA will allow or what ever country the an aircraft resides.

Rotax has no authority over FD, the FAA or any other legal authority here in the US unless they issue an SD which to my knowledge they never have for the 912UL or ULS.
 

 

I'll have the actual FAA verbal scoop Monday.

 

p.s.

I personally believe in the parts replacements and preventative maint. like the 5 year hose and other preventative maint.,

[Roger Lee]

Okay the call is done and had a nice conversation with the FAA this morning.

 

Keep in mind this discussion is on TBO being mandatory and making your LSA certificate ineffective. (don't go off topic)

 

This letter request was from Torrance Keller.

This letter does implicate that a TBO needs to be followed, but the FAA LSA Division believes the author misinterpreted and mislead with some comments. Now this is going to Washington legal because this had already been addressed years ago with the McMillan letter from legal.

We may see a retraction of this letter.

 

Bottom line after a lengthy discussion with the FAA, Rotax nor an aircraft MFG can set any rules or regs above what is already in the FARs. This is the same for Cont. and Lycoming as far as TBO and even though both those engine MFG's say to do a TBO at 2000 hrs. the owner is not forced to do so and may go on condition. Plus FD has no mention of following any TBO in their maint. manual where it needs to be. It only says to follow Rotax inspections. Rotax has nothing about TBO in their maint. manual. No component supplier can make any policy and it would have to come from the aircraft MFG that certified the aircraft and all its components. If the FAA says you can go on condition for any aircraft engine like we are talking about in our scenario then FD or any other MFG can not make new regulatory policy.

 

Quote from FD maint. manual;

 

"Engine.

Inspect all systems as required in the Maintenance Manual

for ROTAX Engine Type 912 Series.

 

 

Bottom line is nothing has changed and you can go past TBO on condition as the FAA legal ruled years ago.

I will however be getting a call back from the FAA after legal looks at this letter, but this may take a week and then I'll post a follow up.

[gbigs]

LSA is different than the certified world in this specific way, that the manufacturer dictates maintenance requirements, including TBO.

 

I am following the Rotax maintenance manuals and service bulletins.  Others can fend for themselves and take their chances.

[Roger Lee]

"LSA is different than the certified world in this specific way, that the manufacturer dictates maintenance requirements, including TBO."  

 

"LSA is different than the certified world in this specific way"   No it isn't. Where did you get this impression?

 

LSA MFG's can not supercede FAA rules. 

 

There is nothing in the FD maint. manual that says to follow the engine MFG's TBO. If there is I would like to see it. There is nothing in the Rotax Line maint. manual about following TBO either.

 

Here's a quote from the Rotax forum from Rotec ( I know it isn't the US, but is applicable for consideration):

 

"If you have well trained Techs AND just as important, well trained pilots/instructors you can go well past TBO."

 

 

As soon as I hear back from the FAA LSA division I'll give you their direct phone number.

 

 

Here is ROAN's On condition document as an example:

 

 

 

and here is the Macmillan report from 2011. This is the legal interpretation from the FAA and why this other letter misspoke.

ROAN guidelines for going on-condition.pdf

MacMillan.pdf

[Doug G.]

LSA is different than the certified world in this specific way, that the manufacturer dictates maintenance requirements, including TBO.

 

I am following the Rotax maintenance manuals and service bulletins. Others can fend for themselves and take their chances.

How do YOU follow these? You are not licensed to do inspection or anything else. The exception being minor user maintenance.

If you take your plane to someone else they are the ones that sign off on the planes condition and they are the ones that determine what rules to follow before that sign off. All you do is make a request for the work and then pay for it, and accept responsibility for it as PIC every time you fly.

How exactly do YOU "follow the FD and Rotax manuals"?

You play the expert card constantly when you haven't been to a class and don't do the work.

[gbigs]

How do YOU follow these? You are not licensed to do inspection or anything else. The exception being minor user maintenance.

If you take your plane to someone else they are the ones that sign off on the planes condition and they are the ones that determine what rules to follow before that sign off. All you do is make a request for the work and then pay for it, and accept responsibility for it as PIC every time you fly.

How exactly do YOU "follow the FD and Rotax manuals"?

You play the expert card constantly when you haven't been to a class and don't do the work.

 

What are you talking about?  I am an owner with the responsibility to keep the aircraft airworthy...as are all owners.  Anyone owning an LSA better follow the rules or find their A/C rendered invalid, including you....

[Doug G.]

Certainly, didn't I say that? What pportion of the Rotax line maintenance and FD inspection instructions do you actually perform? Not muchI hope or you are violating the rules, right?