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How do you track maintenance requirements?

Recommended or Required?

Posted by mike.busch on 09.22.08 at 03:55 AM

Recently, my company SAMM was managing the annual inspection of a client’s Cirrus SR22 at a well-known maintenance facility in Texas. The inspection found very little wrong with the airplane, and it looked like the annual would be completed quickly and inexpensively. Then, quite unexpectedly, the IA responsible for the annual went to work for another shop, and a new IA was assigned to take over. Things quickly went downhill after that.

The new IA informed us that he would not be able to sign off the annual unless we agreed to have both TCM/Bendix S-20 magnetos overhauled or replaced, something that would add nearly $2,000 to the cost of the annual and delay its completion by at least a week. He stated that the magnetos were required to be replaced or overhauled because they had been in service for more than 4 years.

We told the IA we saw absolutely no reason to overhaul or replace the magnetos, and would not approve this work. The IA stubbornly refused to sign off the annual unless this work was done. After several back-and-forth iterations, it became obvious that we were at an impasse with the IA.

 

At that point, we took the only reasonble course of action available to us under the FARs: We directed the IA to sign off the annual with discrepancies, obtained a ferry permit from the local FSDO allowing the aircraft to be flown back to its home base, and then had a local A&P there make logbook entries clearing the “non-discrepancy discrepancy” that the IA had recorded, and approving the aircraft for return to service. (The local A&P saw no reason to overhaul or replace the mags, either.)

What was the shop thinking?

In subsequent correspondence with the manager of the Texas shop, we learned more about why the new IA had decided to take the action he did. The shop manager wrote:

We had an honest difference of interpretation of the maintenance regulations with respect to TCM magneto time/life. Please allow me to outline our view. To be clear, there are two very different TCM magneto inspection and overhaul/replace criteria to be met.

First, there is a 500 hours-of-use inspection. This is commonly done at any full service maintenance facility, and there has been no debate about this requirement. It is nothing new, and it is common industry practice to perform this inspection at 500 hr intervals. In fact, to complete an annual any shop must perform this inspection if due. I think anyone in the industry would agree..

Second, there is a relatively new 4 years time-in-service or 5 years since-date-of-manufacture requirement to either overhaul or replace TCM magnetos. This fairly recent change was published by TCM as a revision to SB643B. (http://www.tcmlink.com/pdf2/SB643B.pdf) Our three very experienced and well-respected IAs on staff here have concluded that TCM magnetos must be overhauled or replaced on a 4-year time-in-service schedule, and that neither we nor any other maintenance facility has any leeway with respect to this requirement.

The key points in the revised Service Bulletin SB643B are in the first and the last paragraphs. The first paragraph says, “The following information constitutes the manufacturer’s Instructions for Continued Airworthiness [emphasis added] ...” While this is a service bulletin and is therefore by definition optional, TCM chose to add the language “Instructions for Continued Airworthiness” or ICA. 

This language—highly unusual for a Service Bulletin—led to our interpretation that the 4yr/5yr requirement is not optional based on FAR 43.16 “Airworthiness Limitations” which states, “Each person performing an inspection or other maintenance specified in an Airworthiness Limitations section of a manufacturer's maintenance manual or Instructions for Continued Airworthiness shall perform the inspection or other maintenance in accordance with that section...” 

Section 4.C of SB643B then spells out the ICA requirement that “...magnetos must be overhauled or replaced at the expiration of five years since the date of original manufacture or last overhaul, or four years since the date the magneto was placed in service...”

Our own opinion based on experience is that the 4-year overhaul/replace requirement is too aggressive and does very little to enhance the safety of these aircraft. But until we can obtain some written guidance to the contrary, we feel that we have no option but to abide by the regulatory requirement as stated in SB643B.

Why the shop was wrong

It is apparent from this correspondence that the IA at the shop in Texas did not arrive at his decision lightly. His position was thoughtful and logical. Unfortunately, it was also wrong.

I decided to write this article because I think it’s important for aircraft owners and mechanics alike to understand precisely why the IA was wrong, and why the 4-year magneto overhaul/replacement is not required. The same logic used by this IA to conclude that the magnetos had to be replaced is also used by many other mechanics and shops to justify all sorts of other maintenance “requirements” that aren’t actually required.

The Texas IA’s principal mistake was misunderstanding the meaning of FAR 43.16:

§43.16. Airworthiness Limitations.
Each person performing an inspection or other maintenance specified in an Airworthiness Limitations section of a manufacturer's maintenance manual or Instructions for Continued Airworthiness shall perform the inspection or other maintenance in accordance with that section...

The critical point that the IA missed is that TCM SB643 (which he is relying upon for authority on the 4/5-year “requirement”) does not contain an “Airworthiness Limitations” section. In fact, according to TCM’s Loren Lemen (who is the person responsible for writing TCM’s maintenance manuals and ICAs), no current TCM maintenance document contains an “Airworthiness Limitations” section. Likewise, very few Beech, Cessna, Mooney or Piper maintenance manuals contain an “Airworthiness Limitations” section.

So long as a maintenance manual or ICA does not contain an “Airworthiness Limitations” section (and most do not), FAR 43.16 does not apply.

As it happens, the approved maintenance manual for the Cirrus SR22 does contain an Airworthiness Limitations section. It covers such things as the airframe life limit, and 10-year mandatory parachute repack interval, and the 6-year mandatory replacement of the parachute reefing line cutters. (All of those items are therefore required by regulation.) But it doesn't say a word about magnetos.

The Texas IA also seemed to ignore the fact that TCM SB643 is a manufacturer’s service bulletin and therefore ipso facto non-compulsory. We have an official Letter of Interpretation from the FAA Office of General Counsel that states unequivocally that compliance is never required by regulation with any manufacturer's service bulletin.

Here's the key point that every aircraft owner and mechanic needs to understand: No manufacturer can mandate any maintenance requirement on a Part 91 aircraft owner; only the FAA can do so. The FAA may mandate a maintenance requirement in three different ways:

1.      In the Type Certificate Data Sheet (TCDS) for the aircraft, engine or propeller.

2.      In an FAA-approved “Airworthiness Limitations” section of a manufacturer's maintenance manual or Instructions for Continuing Airworthiness.

3.      In an Airworthiness Directive.

If a maintenance requirement is not mandated by the FAA in one of these three ways, then it is not required by regulation for a Part 91 operator.

Recommendation vs. requirement

The manager of the Texas shop also spoke about a 500-hour time-in-service inspection “requirement” for mags. This disassembly inspection is not a regulatory requirement, either, only a manufacturer recommendation. It happens to be a good recommendation, and one that I agree with wholeheartedly. I do this 500-hour inspection on my own aircraft, always advise my clients to do it, and believe that it is important to ensure continued reliable operation of the magnetos.

However, I never refer to the 500-hour mag inspection as a “requirement” because it is not. It's simply a recommendation, and a good one. Many operators go far beyond 500 hours without opening up their magnetos for inspection, and while they may be imprudent in doing so, they are not in contravention of any FAA regulation.

Now, it’s very likely that the Texas shop works on multiengine turbine aircraft and/or large aircraft above 12,500 pounds gross weight. The rules for those aircraft are completely different; they are required to be maintained in accordance with the manufacturer's recommended maintenance program. Thus, for such aircraft, a manufacturer’s recommendation does become a regulatory requirement.

But small piston or single-engine turbine aircraft are maintained under a far less exacting set of rules, the requirements for which are set forth in Part 43 Appendix D. Those aircraft are not required to be maintained in accordance with manufacturer recommendations. For such aircraft, manufacturer’s recommendations are only that: recommendations.

When I maintain my own airplane, or advise my clients on how to maintain their aircraft, I advise following manufacturer’s recommendations when they make sense, and to disregard them when they do not make sense. The Texas IA and I seem to agree that arbitrarily replacing or overhauling magnetos every four years does not make sense. The difference is that he believed it was required, while I know it is not.

Methods, techniques and practices

Another much misunderstood regulation is FAR 43.13, which states in part:

§43.13 - Performance rules (general).
(a) Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer's maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, and practices acceptable to the Administrator, except as noted in §43.16. …

This regulation is often misinterpreted by mechanics to mean “if it’s in the maintenance manual, then you have to do it.” But that’s not what it means, at least for Part 91 operators of small piston or single-engine turbine aircraft. The key to understanding FAR 43.13 is the phrase “methods, techniques and practices.” That phrase refers to how to do something, not when to do something.

In other words, if the manufacturer’s maintenance manual or ICAs tells us to do some maintenance task every 500 hours or 4 years or 2500 landings (or whatever), that’s simply a recommended interval and we (as Part 91 operators) aren’t required to comply with those times if we don’t want to. However, if we ultimately decide to perform the task at some point, then we are obligated to do it in precisely the fashion spelled out by the manufacturer in the maintenance manual or ICAs. The manufacturer’s “how-to” instructions are compulsory, but the manufacturer’s “when-to” instructions are not.

For example, suppose the maintenance manual tells us to remove, clean, gap, rotate and reinstall spark plugs every 100 hours. This is merely a recommended interval, and we’re not required to do it every 100 hours if we don’t want to. However, if the maintenance manual tells us to torque the spark plugs to 330 ±30 inch-pounds, then whenever we decide to do spark plug maintenance, we are required to install the plugs to the manufacturer-prescribed torque. The 100-hour interval is a “when-to” (and therefore not mandatory), while the 330 ±30 inch-pound torque is a “how-to” (and therefore mandatory).

The exception is that a “when-to” becomes mandatory if it is prescribed in (1) the aircraft, engine or propeller TCDS, (2) in an “Airworthiness Limitations” section of the maintenance manual or ICA, or (3) in an Airworthiness Directive. 

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bdupont on Tue, 09/22/2009 - 13:48

I read the blog posted by mike.bush on 9.22.08. The new Teledyne Bendix manual printed November 2005 changes the wording (example page 2-2 (E)) from recommended overhaul evey 4 years to must be overhauld every 4 years. How does that affect your arguments?

Anonymous on Mon, 12/28/2009 - 15:42

I read with interest your assesment of the related FAR's and observations regarding the magneto replacement/overhaul. I agree with most of it and think that a reasonable A&P / IA might share your interpretation.

One factor of concern here is that if you step back a bit and look at the broader picture you may see another scenerio.

Lets assume that at some point in the future the airplane crashes and there is injury or death. The cause may even be unrelated to the magnetos but if it was determined that you did not follow a manufacturers reccomendation it gives the plantifs council material to build a case. These events are usually punctuated by lawsuits that result in a jury trial. This means that 12 people likely with little aviation experience will judge the case based on what they belive is the gravity of a manufacturers reccomendation, suggestion, ICA, or assigned time limit. The prosecuting attorney will likely point out to the jury that the magneto manufacturer tried to establish a requirement that they felt should be met to keep the airplane safe. What do you think that jury's verdict would be? Often times we as aircraft maintenance personnel must consider how civil law would be applied what we have done. Even if the case was decided in your favor, the $2000.00 overhaul would be a far cheaper option.

No, I am not an attorney. The mags will probably work fine until some other requirement comes along that would require replacement. Hopefully you will never encounter a situation as I have mentioned above. It is, however, food for thought .

Anonymous on Tue, 03/30/2010 - 13:11

Good article, and I agree with virtually all of it. The one statement that most Cessna and Piper manuals etc lack airworthiness limitations should be edited to say something like "except for Cessnas etc certificated under 14 CFR Part 25."

I think you'll find they commonly have AWL sections in them where part 23 aircraft, as you stated, rarely do.

Bubba1090 (not verified) on Mon, 07/19/2010 - 15:35

Although I do not agree with many SAMM (i.e. Mike Busch) positions or activities, this particular one should be abhorrent not only for me but to the overwhelming number of self-respecting technicians in our industry for several reasons. I've debated this particular discussion about 3 or 4 years ago but I'm willing to rehash it here.

Some underlying information, SAMM's primary business plan (in my opinion), is to prevent you, the FBO, a shop or an individual technician from developing a healthy business relationship with your customer. Their so far successful plan drives a wedge of doubt and mistrust between the shop and customer. Their position is that everyone is dishonest and deceiptful and only they can save you, the owner, from the unscrupulous world of aviation maintenance... FOR A PRICE!!! Just follow the link in the article and you'll find this statement: "Savvy is the first and only organization to provide professional maintenance management for owner-flown aircraft." Really? The '...first and only... professional'? Personally, I take offense to the inference and this is a perfect example of why!

Let's start with §43.16. Airworthiness Limitations.
Each person performing an inspection or other maintenance specified in an Airworthiness Limitations section of a manufacturer's maintenance manual or Instructions for Continued Airworthiness shall perform the inspection or other maintenance in accordance with that section... to which they say "So long as a maintenance manual or ICA does not contain an “Airworthiness Limitations” section (and most do not), FAR 43.16 does not apply."

The legal word in here is OR people, two letters, one syllable - OR... If a manufacturer issues an ICA, it does not have to be in an Airworthiness Section of a maintenance manual! Why Bubba, you ask? What's that two letter, one syllable word? OR is why!

The article further sez that "No manufacturer can mandate any maintenance requirement on a Part 91 aircraft owner; only the FAA can do so." HORSE HOCKEY! The FAA doesn't have the requisite expertise to issue demands on manufacturers and tell them "how to" maintain their products! The FAA certainly oversees, communicates and approves manufacturers and their processes but they do not tell them how to maintain their products. That's called liability folks, and the FAA doesn't do that.

The article goes on to quote "Another much misunderstood regulation is FAR 43.13, which states in part: §43.13 - Performance rules (general). (a) Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer's maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, and practices acceptable to the Administrator, except as noted in §43.16.

Let's see who has been paying attention here. Why is this part and parcel to the true interpretation of the regs? That's right, that two letter, one syllable word - OR. Very good people!

Here's another thing. Look at SAMM's corrective action with the shop in Texas. They got a ferry permit and flew it to a shop where someone else signed it off!!! Hello... If you're that good and you're that all-knowing, put your name in the sign off, not some svengali-like dupe's name who doesn't know any better! I believe the phrase is 'Put your money where your [first and only professional] mouth is...'

Let's talk about the legal side of this argument now. The article sez "We have an official Letter of Interpretation from the FAA Office of General Counsel that states unequivocally that compliance is never required by regulation with any manufacturer's service bulletin." Let me share some other information about this letter. It was written circa 2000 by a female minority staff attorney, issued without internal discussion and that brought immediate chaos within the FAA legal department. The writter was chastised and sanctioned and if you ask for that letter today you'll be told it was recinded. The FAA can't even tell you what they think, how can SAMM?

This entire article is the subjective drivel of the author with whom I am diamterically opposed (as if it weren't evident). His overinflated experience levels [he once stated he had seen "hundreds" of prop overhauls while spending an entire week at Santa Monica Propellers!] have impressed many. But statements like 'Our own opinion based on experience is...' [really? more experience than the manufacturer?] and 'I decided to write this article because I think it’s important for aircraft owners and mechanics alike to understand precisely why the IA was wrong...' [Is that the Supreme "I"? Personally, I don't think the IA was wrong! Does that carry less weight?] show a lack of respect for other aviation professionals and are not only proffesional insults but are extremely egotistical as well.

Am I the only person who sees the unmittigated gaul espoused in these statements? Does the title "Mechanic of the Year" entitle anyone to usurp the knowledge, power and authority of the FAA and every manufacturer in aviation? Well, maybe just that year but not into perpetuity! [sarcasm] Everyone is entitled to his or her own opinion but to spout it as gospel is outrageous. What's worse is to profit from the confusion that is self-instigated. If you've read my blog on unions in 'Miscellaneous Comments' you've just read something that is exponentionally more disgracing...

P.S.
Like any good cop would, you have to take both sides at face value. I don't want anyone to take me as gospel either but I do want you to research this info! Those of you who are connected to Cirrus and TCM particularly are asked to get 'off the record' answers to the questions about SAMM and I'm confident in what you'll find...
__________________
Bubba Sez... May you always have a tail wind & keep your scarf out of your rudder...

Bubba1090 (not verified) on Thu, 07/22/2010 - 14:37

Quote:
[Originally Posted by rdmmdr
Since all maintenance has to be done according to the current manual. But under 91 i do not have to follow icas for an annual. Scary i know, and yes stupid. But if you tell the customer why you are doing it, and that you will not sign off his annual without it before hand, you should not have a problem. rick ]

I agree with most of your post except the Part 91 info. Nowhere in the regs covering ICAs does it say ICAs must be complied with except on those aircraft flown under Part 91. If you stop and think about what you said, it doesn't make sense. No matter how the aircraft is flown, if an ICA exists and it's for that aircraft or any part thereof, you gotta do it! Easy example: Cessna 152 with a G240 something battery, Gill has ICAs for their entire battery line and during the annual, if it has a Gill battery installed you must comply with the ICA...

BTW, I wonder if our friend Ask Bob is following this string? Mike Busch got a lot of softballs tossed back on Bob's site!!! I sure would like to see this string cross-posted on Ask Bob, how about you people?
__________________
Bubba Sez... May you always have a tail wind & keep your scarf out of your rudder...

Bubba1090 (not verified) on Thu, 07/22/2010 - 15:46

Bubba Sez... BTW Mark...

--------------------------------------------------------------------------------

Your customer rep is a flamer! The purpose of inspection is to find! There are no limitations, constrictions or boundaries during an inspection. There are no dark glasses, blinders or blinkers put on a technician. In fact, you've heard me say this before, you are your own quality control. Personally, I would want to find every minute discrepancy that exists anywhere, every time I perform any task on any aircraft cuz THAT'S OUR JOB! Especially for a squawk like corrosion! Nothing sez you must repair every squawk immediately but you definitely should write it up, make an evaluation on whether it's a safety of flight or 'cosmetic' issue and then determine when and how it will be addressed...

Example: You're gonna run-up an Arrow for an oil change and while you're untying it you notice a hydraulic leak under the wheel. What do you do? Under the customer rep's philosophy, you do nothing cuz you're doing an oil change! But we all know what the correct answer is and we all do it cuz THAT'S OUR JOB!
__________________
Bubba Sez... May you always have a tail wind & keep your scarf out of your rudder...

AskBob on Thu, 07/22/2010 - 15:52

Glad to add you comments to the article Bubba. Discussion of these issues is a good thing and gets us all thinking and I would hope improves the field. I would be glad to cross post the other comments if it is OK with the authors.

Anonymous (not verified) on Fri, 07/23/2010 - 05:54

Last year, after reading "Ask Bob's" explanation, we researched the subject extensivly, flollwing the FAA regulation trail. Bob is correct! The operative rulling by the FAA is that only the FAA can make an inspection manditory (effectively it is makeing an item time lifed and the regs say that only the FAA can do that). (AD"s are an example).

The manufactueres can do it by creating an "Approved Airworthiness Limitations Section" in a service manual, or by an "Approved ICA" IF the ICA is not signed by the FAA as FAA Approved then it is advisory in nature and you can't be forced to comply with it.

It is the same line of thought that went into the argument about whether service bulletins were manditory, the FAA struck it down. I am not saying that some of these recommendations are smart, I used to refuse to work on helicotpers whose owners wouldn't comply with service bullitins, but we as techincians are not robots and should be using our heads about spending our cutomers money, or we won't have any.

There are some cases such as the 4 year Bendix overhaul requirement that are just a screw job for the custome, brought about by the manufactuer haveing to defend against some law suit.

bob.pasch on Mon, 11/01/2010 - 09:28

I am just astounded by the number of people who comment and refuse to reveal their identity. I have a major problem with "anonymous" as a respondent! What are you 'experts' afraid of? Be a man [or woman], if YOU state an opinion, please, have the fortitude to tell us who you are!!!

Now to address your comments. Anonymous Inc. ownes a Beech King Aire 200 operated under Part 91. According to your interpretation, I can perform one annual inspection and be legal when we all know the aircraft must be maintained under a Beech Phased Maintenance Program [unless otherwise requested and approved]. Splain that one, Ricky...

__________________

May you always have a tail wind and keep your scarf out of your rudder...

Fredmaint1 (not verified) on Thu, 03/03/2011 - 18:59

Here's a few thoughts about Mikes' artical that IA's may want to consider...

1) The IA performing the Annual Inspection was presumably employed by a reputable shop, factory trained, fairly compensated, definately responsible, and surely aware of our legal systems love affair with law suits...Do you really think this IA was in error, requiring the magneto inspection / overhaul? Do you really think he was out to "Shake-down" this customer? Why should a shop even invest in factory training if they are not even going to implement improvements in their maintenance program?
Does the term "Preventive Maintenance" ring a bell???

2) The generous and couragous A & P mechanic who signed off the discrepancy as airworthy...Do you think he was employed by an established, factory trained shop, with established and thought out processes, or maybe an "independant", with little or nothing to loose?

3) As stated earlier...What if, after all was said and done, the aircraft and operator were involved in an accident??? ANY kind of accident...Would the Texas shop be named in the insuing lawsuit??? The diligent IA??? The courageous A & P??? Cirrus??? TCM???Mike and his company SAMM??? All of the above!!! What if during the investigation it was determined that some form of magneto failure contributed to the accident? What if the accident included fatalities?

Looks like Good Ole' Mike's name can't be found anywhere in the log book!

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