FAA response to mandatory maintenance intervals

[Anticept]

The FAA considers part 61, 91 operators and part 65, 43 maintenance to be two separate things. For example, if an aircraft has an annual inspection and has the IA's signature, then the operator is off the hook (so long as they don't knowingly fly with ADs, for example, which requires both 61 (as an operator) and 65 (as an inspector) airmen to be compliant).

 

S-LSA maintenance is considered the same. That's the technicality behind the TBO that has been used. 61 airmen are not mechanics, and 65 airmen are not pilots. Therefore the mechanics don't have to follow the operating limitations of the manuals, while the 61 airmen don't have to follow any maintenance schedules that are not imposed by the FAA. Mechanics do have to follow any APPROVED airworthiness limitations sections (manufacturers cannot just write things in this section, it requires approvals, which means it will have an approval notice from the FAA in that section), but since the FAA does not approve anything in the rotax manuals, that's where the hitch is, and thus an enforceable "life limit" is not established. This interpretation has not served to clear up the controversy, despite the attempt.

 

Other ops parts, such as 121, 123, and 135, make manufacturer recommendations mandatory by regulatory enforcement, and therefore TBO becomes required in those ops.

[gbigs]

Let me spell it out...as an owner and responsible for following the rules for SLSA I will adhere to Rotax time limits (in order to keep a valid airworthiness certificate), to wit:

 

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

 

As an owner I will follow Flight Design's rules and requirements (like the parachute repack after 5 years for example) and will get annual inspections and keep the required equipment in good working order. 

 

This DOES NOT mean I will do the work.  Most owners are not mechanics and have no intention of doing their own mechanical work.

[Tom Baker]

100 Ham, are you sure you can even fly your airplane legally? It doesn't even have all the parts that you say needs replacing.

[Anticept]

Let me spell it out...as an owner and responsible for following the rules for SLSA I will adhere to Rotax time limits (in order to keep a valid airworthiness certificate), to wit:

 

That's fine. I don't think most people here go against the manufacturer recommendations. However, that doesn't mean that I want to pop all that power right into their hands. Vendor lock-in is a thing!

 

"In economics, vendor lock-in, also known as proprietary lock-in or customer lock-in, makes a customer dependent on a vendor for products and services, unable to use another vendor without substantial switching costs."

 

By creating regulatory enforcement WITHOUT engineering justification is just asking for the customer to get f***ed eventually. In the certified world, I can use PMA parts. Cessna is famous for charging absolutely outlandish prices for parts, but I can get a PMA'd part, that is the same, if not better quality, for a 5th of the price. Or, I can get an STC to make a modification. I can't do any of this with an S-LSA. Aftermarket parts in cars helps keep the prices in check from OEM, and it has a similar effect with PMA aftermarket parts in aviation.

 

Finally, manufacturers aren't all knowing. They certainly know more than most with their engines, but Rotax is no exception, many of their procedures and manual revisions come from field feedback, and not just from an engineer crammed in a tiny office running computer simulations and math.

 

I respect Rotax's decisions for the most part, but there's a few things that I think they are full of it (200hr carb inspections is way more than needed for CTs), and I certainly do not like the idea of letting them make all the decisions while having the backing of the US Federal Government unless they can provide empirical data.

[FastEddieB]

As far as vendor lock-in being a "thing"...

 

...with most consumer items, there is protection under the Magnuson-Moss Warranty Act.

 

https://en.m.wikipedia.org/wiki/Magnuson–Moss_Warranty_Act

 

For instance, to keep the warranty in effect, Honda cannot require you use Honda oil or filters or other parts, unless they provide them free of charge. Similarly, they cannot require that service be done at authorized dealers. To deny warranty coverage the burden of proof is upon Honda to demonstrate that the oil, filter, part or service played a role in the failure leading to the warranty claim.

 

Large differences exist in the aviation world, but it's still good to be aware of what manufacturers can and can't legally do regarding factory warranties.

[sword_guy]

Monday came and went...  Inquiring minds want to know!

[Roger Lee]

Hi Sword-Guy,

 

The Monday conversation is here on a prior post. I'm waiting for some further FAA communication as the LSA division believes the author of the letter misspoke. It may be a few days more.

[gbigs]

100 Ham, are you sure you can even fly your airplane legally? It doesn't even have all the parts that you say needs replacing.

 

No I don't have old tech carbs on the plane, but do have rubber hoses for cooling and lube system.  Also have a TBO of 2000 hours on the engine...pick out the stuff that applies, leave the rest alone....

[sword_guy]

Yeah, I noticed after I posted that there was a page 2.

[Doug G.]

No I don't have old tech carbs on the plane, but do have rubber hoses for cooling and lube system. Also have a TBO of 2000 hours on the engine...pick out the stuff that applies, leave the rest alone....

First, gasoline fuel injection tech was introduced in 1902, hardly new tech.

Has Rotax come out with a number of hours for injector replacement yet? Or for the higher pressure fuel pump and distribution system?

[Tom Baker]

No I don't have old tech carbs on the plane, but do have rubber hoses for cooling and lube system.  Also have a TBO of 2000 hours on the engine...pick out the stuff that applies, leave the rest alone....

Did you know your engine is not as new tech as you think. I heard one of the top Rotax people explain it as 1980's automotive technology. The plus side is that the technology is well proven just like the carburetors.

[gbigs]

Carbs are old tech.  No modern car has them.  Soon no aircraft will either... 

 

Fuel injected, computer controlled fuel systems are far more efficient, do not ice up, do not require manual manipulation, and apparently have no hose lifetime limits like the carbs do.  And have no leaks in the floats or leaking fuel into drip pans as some have reported on this forum.

 

But this thread is about whether TBO requires rebuild or replacement under LSA rules.  Reading the Rotax maintenance manuals, for Rotax owners, it does.

[Anticept]

The 912 ul and uls are 80's tech. The injected is a little bit newer, I would put it on par with late 90's. Once they can do inflight tuning (when 100LL dies), then I would put it on part with automotive tech.

[Tom Baker]

The 912 ul and uls are 80's tech. The injected is a little bit newer, I would put it on par with late 90's. Once they can do inflight tuning (when 100LL dies), then I would put it on part with automotive tech.

I was just relaying what I overheard a top Rotax say about the injection system.

[Anticept]

Just relaying my own personal thoughts

[Doug Hereford]

I would bet a year's salary that the interpretation will be retracted by the FAA. It is full of inaccuracies.

 

Doug Hereford

[Doug Hereford]

I have a little more time now. I wanted to expand on why I think the legal interpretation is flawed. TBO is not a part of aircraft "configuration". REF 21.181. SLSA maintenance manuals will not contain "life limited parts" either. As someone earlier stated, these limitations must be FAA approved. SLSA maintenance manuals are

merely accepted.

Even if FD were to place TBO requirements in their manual (as opposed to various vendor CMM's), these requirements are not made regulatory. Even if they added hose change requirements or other component replacement requirements, these are also not a part of aircraft "configuration", and therefore not regulatory. Even if they added a specific training requirement, it would not be regulatory. The only way that the SLSA manufacturer might be able to legally impose any of these items would be via Safety Directive. I seriously doubt that this avenue would stand up however, as a Safety Directive must be issued to correct an "Unsafe Condition". Steep burden of proof there.

 

The only portion(s) of SLSA maintenance manual(s) that is/are truly regulatory is/are the portion(s) that specifies "procedures"........... The "HOW-TO's" of performing maintenance (inspection is a type of maintenance). The rest of the stuff is not legally required.

 

In contrast to above, any unauthorized alteration to the SLSA aircraft would render the certificate "ineffective" [(REF 21.181 (3)(ii)] as it does effect aircraft configuration. Further, any alteration that does not meet the applicable consensus standard would also render the certificate "ineffective" even if that alteration were approved by the MFG. (same regulatory reference).

 

As we know, the violation to the operator would not be part 21, but rather 91.203 (as the FAA letter accurately states).

 

Doug Hereford

[Runtoeat]

My 2006 CTSW has it's engine TBO coming up at 2000 hours or 12 years. This means in 2018 I'll need to deal with this. I am following this thread with great interest, as other owners with older CT's are also probably doing. Roger, you indicate using the "on condition" maintenance method for those CT's which have the TBO expiring is something we might consider doing. Let's say I opt to do "on condition" instead of rebuilding or buying a new engine when my TBO runs out. Could you give a outline specific to our CT which tells how you would inspect and maintain my engine using the "on conditon" method? Reading this thread, it seems that most here agree that FD and Rotax cannot "legally" require us to do the TBO. I'm wondering if my insurance company would be satisified with my CT being maintained using "on condition" or would I run into trouble with them because I'm not "following manufacturer's direction"? Last question, have you heard back from Washington? Thanks.

[Roger Lee]

I'm still waiting for the FAA response. When I ask the FAA a few years ago about this they said they actually contacted some insurance companies and the insurance firms said they would follow the FAA's lead without any issues. The on condition inspection for the engine is the same items on the regular check list found in the Line maint. manual that hopefully you have been using all these years for your paperwork trail.

 

 

p.s.

Just tried to call the FAA and the person I need to talk to is out of the office until Aug. 24th. I'll try back then.

[Runtoeat]

Hi Roger, ditto on Bill's comments.  Your atttempt to provide us with the official response by the FAA is appreciated as is your comments about what might be the case for the insurability of our CT should we elect to use on condition maintenance.  Interesting that you say the on condition inspection is nothing more than following the Rotax MM check list.  My mechanic said the same.

[Roger Lee]

There is nothing special about an on condition inspection past TBO. It's the same as the annual and so long as it passes which it should easily you're good to go.

 

If your maint. check list is good enough to keep you in the air over 2000 hrs. then it's good enough for each inspection after.

[FastEddieB]

As a data point, my Sky Arrow annual checklist says, "Overhaul - See Engine TBO Table"

 

Since I've only flown 400 hours in 8 years and just turned 66, I doubt it will ever matter to me one way or another.

 

Still vague curious about how this turns out.

 

BTW, it says nothing about carb overhaul.

[FlyingMonkey]

As a data point, my Sky Arrow annual checklist says, "Overhaul - See Engine TBO Table"

 

Since I've only flown 400 hours in 8 years and just turned 66, I doubt it will ever matter to me one way or another.

 

Still vague curious about how this turns out.

 

BTW, it says nothing about carb overhaul.

 

 

There's also the 12 year limit if you go by the Rotax recommendation.

[Roger Lee]

There is nothing in Rotax print that gives a time to overhaul carbs. They only spec a 200 hr. inspection. So that puts it on condition.

[Roger Lee]

Just got off the phone with the FAA. The letter that went out stating that there was a mandatory TBO for LSA was wrong. The author kind of overstepped and stretched an interpretation. There never has been a required TBO for LSA and you can go on condition. The FAA legal is on board and will issue a letter very shortly spelling this out more clearly so there is no more misinterpretations. Bottom line is no MFG can set policy or a requirement above what the FAA has in place and what is in place is on condition inspections if you so choose at TBO. If you want to spend $12K for an overhaul or buy a new engine then it's your choice.