Another (M)MEL question

[DCR]

I'll try to keep this short:

If an MMEL exists for an aircraft, does it have to be complied with?

Or... are MMELs just for developing MELs, and the MMEL in itself "doesn't matter" if you don't use an MEL for said aircraft.

 

[RyanB]

The MMEL is developed by the manufacturer typically and an MEL is based off of that, but can be unique to the company/operator. If it’s part of the list, then yes it has to be complied with.

 

[DCR]

Sorry, not quite understanding... What are you referring to when you say "the list"? (The MMEL or MEL?)

 

[Jim Carpenter]

Or... are MMELs just for developing MELs, and the MMEL in itself "doesn't matter" if you don't use an MEL for said aircraft.

This.

 

[Bell206]

If an MMEL exists for an aircraft, does it have to be complied with?

MMELs are generic lists that are used to develop a specific MEL for your aircraft. Whether you need an MEL depends on the aircraft operation.

 

[MauleSkinner]

91.213 allows you to defer inoperative items either via MEL or not(91.213(d) is the “not”, IIRC.) In order to use an MEL, you need approval from the FAA. If you have that approval, you must use the MEL and not 91.213(d). If you don’t have an MEL approval, you can use the MMEL as guidance to help you evaluate something you defer under 91.213(d).

An Air Carrier (135, 121, etc.) must use an MEL. Same for turbine aircraft.

 

[DCR]

I think I understand... if I my aircraft doesn't have an MEL then I am operating under 91.213(d). In this case the aircraft's MMEL would be irrelevant to my operation.

 

[MauleSkinner]

I think I understand... if I my aircraft doesn't have an MEL then I am operating under 91.213(d). In this case the aircraft's MMEL would be irrelevant to my operation.

Not totally irrelevant…it can give you some ideas for how to manage certain deferred items.

 

[mandm]

What does the second M stand for? It this a mandm joke?

 

[nauga]

What does the second M stand for? It this a mandm joke?

Minimum. The first one stands for Master.

Nauga,
and his mini-mum

 

[AlphaPilotFlyer]

I wouldn't get into the manufacturers MMEL for GA part 91 ops for a number of reasons. it's there for air carrier or charter operators to come up with their own MEL per their ops specs which the FAA must still approve (usually the carriers certificate management office for larger carriers, or principal operations inspectors for smaller guys like part 135). ....although some 91 operators such as pipe line patrols get it. however. for a personal plane, part 91 ops typically allow greater freedom to fly with inop equipment and trying to get FAA to sign off on your proposed MEL will take time and be frustrating...you will need to demonstrate why you really need this and it will be weight against the safety lost flying with inop equipment . to make your mel you would pick and choose what items in the master mel (mmel) you want relief for and ask Fsdo to approve it. I would avoid it, as approval basis is subjective and items may require some inspection by A&P every so many hours or even each flight, which can be expensive and grounding if no one is available. also, unlike most part 91 deferrals, mel will put a time limit when it must be fixed, so you could strand yourself and then need ferry permit , whereas part 91 would not.

if you want a good gouge/memory aid for what you can defer for your part 91 owned or rented personal airplane, l can offer what I have used and taught for decades as deferring inop equipment is one of the biggest trouble spots for commercial pilots understanding....I don't like giving instruction advice if not asked as not to be one of those guys opining online.

otherwise. there's a faa AC that explains the mel process, but it's a bit old and may not be current. I have worked on submitting MELs and it is more complicated than one would think...it may also be a point of contention with insurance company as they may claim you were insured only based on your planes type certificate and not methods that allowed flight outside those basis or type design....should u have a claim.

 

[MauleSkinner]

also, unlike most part 91 deferrals, mel will put a time limit when it must be fixed,

The time limits in an MEL apply only to 121/135, etc., not 91.

 

[Doc Holliday]

however. for a personal plane, part 91 ops typically allow greater freedom to fly with inop equipment and trying to get FAA to sign off on your proposed MEL will take time and be frustrating...you will need to demonstrate why you really need this and it will be weight against the safety lost flying with inop equipment

Where in the application process does it require the applicant demonstrate a need?

. to make your mel you would pick and choose what items in the master mel (mmel) you want relief for and ask Fsdo to approve it

Most 91 operators use the MMEL as the MEL, so no need to pick and choose.

. I would avoid it, as approval basis is subjective and items may require some inspection by A&P every so many hours or even each flight, which can be expensive and grounding if no one is available. also, unlike most part 91 deferrals, mel will put a time limit when it must be fixed, so you could strand yourself and then need ferry permit , whereas part 91 would not.

Again, not true. The categories for time (A,B,C,D) do not apply to Part 91 operations. Their could be an item that would require continuous inspection depending upon the airplane, but for most 91 ops I haven't seen it.

otherwise. there's a faa AC that explains the mel process, but it's a bit old and may not be current. I have worked on submitting MELs and it is more complicated than one would think...it may also be a point of contention with insurance company as they may claim you were insured only based on your planes type certificate and not methods that allowed flight outside those basis or type design....should u have a claim.

The MEL becomes a part of the TC once the LOA is issued, so not sure where you are coming up with the insurance won't cover under a claim using the MEL. The MEL is an FAA Approved document and is developed with the manufacturer of the aircraft.

I have never seen any insurance documentation that excludes the use of an MEL.

 

[AlphaPilotFlyer]

as a DER thats approved MELs it's not as cut and dry as one would think. The reason even the MMEL must be approved and not a blanket approval, is the specific aircraft and operation is considered. An example would be an aircraft has a non type design STC that requires a specific power redundancy or requirement, say for a IRS nav unit...the MMEL is based on type design and may allow a generator to be inop, but the STC equipment requires more than a single Gen can produce,...hence the mmel can could allow flight causing failure of a critical system, in which case the specific mel item would be modified to have a limit requiring the equipment not be needed and not powered. as far as insurance goes, there was a guy at our hanger that put STC'd floats on his Cessna, he later learned he had no coverage for the summer because even though plane was kept airworthy, the insurance said his plane was not covered for multiple reasons.... the plane was never approved for floats in type design, but the stc made the alteration airworthy but insurance said they took the risk based on type design and pointed to a clause stating somtlike operating outside that listed in TC required notification or approval. essentially, a meal allows an otherwise non airworthy aircraft be air worthy....and I have no doubt that is an insurance carrier could make claim a loss was contributed in some way due to flying in a condition otherwise not allowed under tc, or applying Mel to certain conditions was not well managed. insured could be on even more the defensive. my point being a part 91 mel often comes with unintended issues and don't know what greater freedom it allows compared to without other than for some fleet operators.

 

[MauleSkinner]

An example would be an aircraft has a non type design STC that requires a specific power redundancy or requirement, say for a IRS nav unit...the MMEL is based on type design and may allow a generator to be inop, but the STC equipment requires more than a single Gen can produce,...hence the mmel can could allow flight causing failure of a critical system, in which case the specific mel item would be modified to have a limit requiring the equipment not be needed and not powered.

If someone doesn’t know their airplane well enough not to defer something per the MMEL, how are they going to know not to defer it under 91.213(d)?

 

[Doc Holliday]

as a DER thats approved MELs it's not as cut and dry as one would think. The reason even the MMEL must be approved and not a blanket approval, is the specific aircraft and operation is considered. An example would be an aircraft has a non type design STC that requires a specific power redundancy or requirement, say for a IRS nav unit...the MMEL is based on type design and may allow a generator to be inop, but the STC equipment requires more than a single Gen can produce,...hence the mmel can could allow flight causing failure of a critical system, in which case the specific mel item would be modified to have a limit requiring the equipment not be needed and not powered. as far as insurance goes, there was a guy at our hanger that put STC'd floats on his Cessna, he later learned he had no coverage for the summer because even though plane was kept airworthy, the insurance said his plane was not covered for multiple reasons.... the plane was never approved for floats in type design, but the stc made the alteration airworthy but insurance said they took the risk based on type design and pointed to a clause stating somtlike operating outside that listed in TC required notification or approval. essentially, a meal allows an otherwise non airworthy aircraft be air worthy....and I have no doubt that is an insurance carrier could make claim a loss was contributed in some way due to flying in a condition otherwise not allowed under tc, or applying Mel to certain conditions was not well managed. insured could be on even more the defensive. my point being a part 91 mel often comes with unintended issues and don't know what greater freedom it allows compared to without other than for some fleet operators.

The discussion was a typical GA airplane that wants to get an MEL. You are now diving off into a lot more complicated area than would be in a GA part 91 SE airplane.

As far as an insurance company not covering a plane that was put on floats, well duh, if you don’t list the types of operations then yes the insurance company can deny coverage. But you implied without anything to back it up that somehow an LOA for an MEL would render the aircraft uninsurable. Again, I have never seen any such language in a policy.

If you don’t know what an MEL offers over part 91 deferrals, then you aren’t well versed on MEL procedures.

 

[AlphaPilotFlyer]

Yea, I did drift off the GA center line here...... my bad.

As mentioned above, Insurance required the aircraft remain in its airworthy condition, which means per its type design; even though it remained airworthy by supplemental TC. By installing STC'd floats, adjuster contended it did not conform to its type design (which technically it did not). Merely semantics, but was a point of contention and seemed to be used in the bargaining process. This issue did not occur to owner as the STC made it all legal,,, other insurance criteria aside.

although my background is part 25, i have worked as a DER on an electrical elevator trim some small aircraft (it was incorporated with an autopilot STC program), which MEL and required equipment was addressed as part of STC. I don't believe the C182 test plane, or other like models which STC focused, had a formal MMEL in TC (typically part 91.205 and equipment list cover this). However, even a part 91 operator can ask CAA for MEL relief, such as through a LODA or petition or STC if equipment related, or approved maintenance manual, ect. I think mostly part 91 ops in desolate or extreme areas where waiting for a new fuel gauge would not reasonable.

If granted, such a MEL would not be part of TC but only to that specific aircraft and even operator (unlike a MMEL by manufacturer). As such, insurance could argue you did not keep it conforming to original TC if that is languaged used, as with the floats.

But my point was simply that part 91 and equipment list requirements for SE GA are close to bare bones as it typically gets, and any SE part 91 MEL approved would not likely allow much more approval for inop equipment. In fact, i would argue under most part 91 situations, you are better off without a MEL.

 

[flyingcheesehead]

An Air Carrier (135, 121, etc.) must use an MEL. Same for turbine aircraft.

Not necessarily - But if you don't have an MEL, literally every single thing on the aircraft must be in fully operational condition or you're grounded. Sun visor loose? Grounded. Passenger seat you're not using broken? Grounded. Even on brand new airplanes, not having a MEL in air carrier ops is difficult.

 

[Doc Holliday]

Yea, I did drift off the GA center line here...... my bad.

As mentioned above, Insurance required the aircraft remain in its airworthy condition, which means per its type design; even though it remained airworthy by supplemental TC. By installing STC'd floats, adjuster contended it did not conform to its type design (which technically it did not). Merely semantics, but was a point of contention and seemed to be used in the bargaining process. This issue did not occur to owner as the STC made it all legal,,, other insurance criteria aside.

although my background is part 25, i have worked as a DER on an electrical elevator trim some small aircraft (it was incorporated with an autopilot STC program), which MEL and required equipment was addressed as part of STC. I don't believe the C182 test plane, or other like models which STC focused, had a formal MMEL in TC (typically part 91.205 and equipment list cover this). However, even a part 91 operator can ask CAA for MEL relief, such as through a LODA or petition or STC if equipment related, or approved maintenance manual, ect. I think mostly part 91 ops in desolate or extreme areas where waiting for a new fuel gauge would not reasonable.

If granted, such a MEL would not be part of TC but only to that specific aircraft and even operator (unlike a MMEL by manufacturer). As such, insurance could argue you did not keep it conforming to original TC if that is languaged used, as with the floats.

But my point was simply that part 91 and equipment list requirements for SE GA are close to bare bones as it typically gets, and any SE part 91 MEL approved would not likely allow much more approval for inop equipment. In fact, i would argue under most part 91 situations, you are better off without a MEL.

This is an inane rambling assertion using an example of a plane on floats and insurance that has no relation to the subject at hand (MEL).

Show one insurance policy that states the use of an FAA Approved MEL will invalidate the policy.

 

[MauleSkinner]

But my point was simply that part 91 and equipment list requirements for SE GA are close to bare bones as it typically gets, and any SE part 91 MEL approved would not likely allow much more approval for inop equipment.

Maybe you should stop there, and not use ridiculous examples that detract from your position.