Bumper

Is legal to use the manufactures MMEL under Part 91in the US only in a turbojet airplane without an LOA from the FAA? I have read over 91-67A and 91.213 am I missing something? An older pilot was stating that you don't need an LOA to use the MMEL.We are in a disagreement. Were you allowed to use the MMEL without an LOA in the past?

Thanks

MstrAv8r

when I was flying an FAA certified aircraft for the Army, we used the MMEL with no LOA. Our A&Ps used it to determine the airworthiness of the aircraft when we had inop or downgraded equipment. For what it’s worth.

Bumper

Thanks for the reply what time frame where you using the MMEL with no LOA?

JohnBurke

In order to be airworthy, the aircraft must meet a two-prong test: it's safe, and legal. Safe has pre-defined, and subjective values and is always subject to judgement. Legal is not so subjective, but also not always black and white.

In order to be airworthy, the aircraft must conform to it's certification; everything must work and function as intended, per manufacturer documentation. It's it's structural or installed, it must be functional, unless relief is granted by the regulation, with certain exception (worn paint, for example, maybe a cosmetic issue, or may be an airworthiness issue).

14 CFR 91.213 (https://www.ecfr.gov/current/title-14/chapter-I/subchapter-F/part-91/subpart-C/section-91.213) covers inoperative instruments and equipment, and stipulates that one cannot takeoff with either inoperative, unless certain conditions are met. The first that is listed is an approved minimum equipment list. The second provision is that the aircraft has on board a letter authorizing the minimum equipment list.

One cannot simply defer an item per the MMEL, and leglly comply with 91.213, unless the use of the MEL is authorized for that aircraft. One can get the entire MMEL authorized, verbatim, if desired, but the authorization letter is still required.

The original aircraft as it came from the factory may be modified by various means, including a supplemental type certificate (STC); legal modifications to the airplane thus modify the original type certificate by making authorizations to add or remove or modify the airframe, engine or accessories in some way. This is the function of the MEL: it functions as a supplemental type certificate on a temporary basis to allow modification of the aircraft, by authorizaing inopeative items or equipment, in a manner acceptable to the administrator (and designed and developed through the FAA's Aircraft Evaluation Group--which develops all MMEL's). In order to avail yourself of the MMEL, an approval for that aircraft by that operator or individual or owner, is required.

Except...

If you're operating a turbine aircraft and you want relief via the MEL, then it's got to be approved. If it's something other than a turbine aircraft (eg, either aotorcraft, non-turbine-powered airplane, glider, lighter-than-air aircraft, powered parachute, or weight-shift-control aircraft, for which a master minimum equipment list has not been developed; OR a small rotorcraft, nonturbine-powered small airplane, glider, or lighter-than-air aircraft for which a Master Minimum Equipment List has been developed), then so long as the equipment is not regulatorily required (minimum day VFR equipment, for example) under the operating conditions, the inoperative equipment maybe deactivated or removed, and placarded, and under 91.213 this also supplements the type certificate or modifies it in a manner acceptable to the administrator.

Short story, if you're operating a large rotorcraft or large airplane, and a MMEL exists, you have to adapt it to your aircraft and get that adaption approved, and you have to carry that approval on board, and use it. If its anything else (listed above), the MEL use is optional.

Whether you have a MEL or not, there are certain things which cannot be MEL'd, and must be functioning, such as required instruments and equipment for the operation or operating conditions (IFR, for example). If the equipment is part of an AD requiring it's function, then it's got to be installed and functional. Some aircraft feature a Kinds of Operation required-equipment list, usually found in the flight manual, which also dictates what must be working for certain operations or conditions.

For a Part 91 operation only (eg, not 121, 135, etc), the MEL is used via a letter of authorization, but is not an "approved document." Once issued, the letter of authorization and the MEL use is mandatory, as are any applicable (m) and (o) procedures associated with the MEL. All applicable approved documents, such as the manufacturer and component maintenance documents, must also be adhered, in accomplishing the procedures (to include personnel, required equipment, practices, tools, and techniques). Again, the approval letter and the MEL, when used, constitute a temporary STC for the aircraft, and form the basis for continuing airworthiness with that inoperative item. It should go without saying that any maintenance, including compliance with the MEL, is not valid or completee without the appopriate maintenance entries (log entries); lack of that documentation invalidates the airworthiness certificate (makes the aircraft unairworthy) because the aircraft is no longer in compliance with it's type certificate as ammended.

You can use the MMEL (should develop your MEL from the MMEL), but you also require an approval letter to use that, because that's the legal basis that allows the MEL to temporarily modify the airworthiness of your aircraft to be legal: that approval letter is itegral to acceptance of the MEL use as a temprary STC.

https://www.aviationpros.com/aircraf...to-have-an-mel

JamesNoBrakes

There are two ways to operate with an MEL/MMEL Part 91.

91.213(a)(1) and (2). For Part 91, you can get an approved MEL, or you can get an LOA authorizing you to use the MMEL. These are the two situations in (a)(1) and (a)(2) and inspectors have guidance on how to do either one of these. (a)(1) is obviously much more complex, but corporate flight departments and anyone else that wants or is required to use an MEL does this. It is functionally the same as what a 135 or 121 MEL would be, adapted to Part 91 operating rules and any other aspects of the specific operation being conducted obviously. (a)(2) is much simplier and leaves a lot for the operator to "make up", in terms of what alternative actions or procedures they will do.

It goes on to say that the only other relief outside of a special flight permit is through 91.213(d)

So it appears no, you cannot just grab an MMEL and use it, you need the LOA, as it says in the regulation.

Also, manufacturers don't make the MMEL, the FAA Flight Operations Evaluation Board does, with input from the manufacturers and industry participants. Anyone can participate in their meetings and suggest revisions to an MMEL. Many industry stakeholders do just this. https://drs.faa.gov/browse/MMEL/doctypeDetails

JohnBurke

Whether one uses the MMEL verbatim, or uses it as the basis to tailor one, is largely irrelevant. Regardless, one must have an authorization letter, in order to legally use that minimum equipment list for inperative instruments or equipment. There exists no legal basis for simply plucking the MMEL out of the ether and using it, without authoirzation. With that in mind, the degree to which the MMEL is customized is irrelevant, so far as the requirement for a letter of authorization.

JamesNoBrakes

I didn't say there was legal basis for pucking the MMEL out and using it without authorization. There are two differnet possible authorizations, based on the regulatory authority I showed above. One results in issuance of D095, MMEL with an LOA, one results in issuance of D195, operator-developed MEL. The Ops Specs are a way to track who has these authorizations. As a note, the Ops Specs are referred to as "LOAs" for Part 91. Each of these options is "approved" by the FAA. The List of Effective Pages for the D195 is signed, indicating MEL approval, just like any Part 121 or 135 MEL. The issuance of the D095 in the MMEL case constitues approval to use. If you want to read this, it's in 8900.1 Volume 4, Chapter 4, Section 2. Part 91 MELs. I'm just showing these are the only two options outside of 91.213(d).

rickair7777

Long story short, as long as I've been doing this (long time but probably not as long as JB), you cannot just unilaterally adopt and use a MMEL without FAA approval.

So no, you can't just decide to start using it one day.

Bumper

Thanks for the input, we are looking into getting LOA for RVSM, MEL through a third party and researching on other LOAs for Central / South America and Canada.

Is Canada requiring MEL for US registered aircraft? Have atrip in Sept. but dont think all LOAs will approved by then. The owner initially said no international ops but likes his new jets and want to go places.

JohnBurke

Going abroad without a means to address a mechanical discrepancy is a bit like going for a long trip in the family jalopy without a spare tire. If you're gonna get the toy, get the means to use it. For a large or turbine airplane, that includes a MEL.

If you don't want a custom-tailored MEL, then for the shorter term, adopt the MMEL and get it authorized for your aircraft. Why would one operate without it, domestic or abroad?