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ADD's
Someone posed a very interesting question to me a few days ago regarding the extensions given by local regulatory authorities to operators to Authorised Deferred Defects:
If Boeing or Airbus says that a particular defect must be fixed within a certain time according to the MMEL, shouldn't be fixed within that time?What authority or experience does the local CAA or DCA have to extend the stipulated period?
Now I asked around and didn't quite get a satisfactory answer. Engineers say that the CAA can do this as they may have had a lot of experience with a particular type or defect such that they know that safety won't be compromised by the extension. Some even told me that a perticular authority in the middle east says that " Extending the period is a matter of national security, as keeping a national airline from operating is a security risk"!
What I would like to know is whether the manufacturers support these extensions, and if so where is this documented, because -to be simplistic about it- these regulatory authorities have basically made themselves test pilots and design engineers by allowing these extensions. If Boeing or Airbus didn't think the time limits were pertinent, they wouldn,t have put them in the MMEL's in the first place.
Thanks to all in anticipation.
If Boeing or Airbus says that a particular defect must be fixed within a certain time according to the MMEL, shouldn't be fixed within that time?What authority or experience does the local CAA or DCA have to extend the stipulated period?
Now I asked around and didn't quite get a satisfactory answer. Engineers say that the CAA can do this as they may have had a lot of experience with a particular type or defect such that they know that safety won't be compromised by the extension. Some even told me that a perticular authority in the middle east says that " Extending the period is a matter of national security, as keeping a national airline from operating is a security risk"!
What I would like to know is whether the manufacturers support these extensions, and if so where is this documented, because -to be simplistic about it- these regulatory authorities have basically made themselves test pilots and design engineers by allowing these extensions. If Boeing or Airbus didn't think the time limits were pertinent, they wouldn,t have put them in the MMEL's in the first place.
Thanks to all in anticipation.
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Hello.
As from the OEM side (be that Boeing, Airbus, Bombarider, Embraer or anybody else) if you're given any time constraint it is up to the airline to follow it.
If the CAA declares that the time limit on the part can be extended then they take full responsibility. Otherwise you absolutely need to consult the OEM on extension.
I would have a big problem to fly an a/c that has, for example, an extended inspection interval on an ALI defined by local CAA contrary to OEMs requirements.
Cheers,
As from the OEM side (be that Boeing, Airbus, Bombarider, Embraer or anybody else) if you're given any time constraint it is up to the airline to follow it.
If the CAA declares that the time limit on the part can be extended then they take full responsibility. Otherwise you absolutely need to consult the OEM on extension.
I would have a big problem to fly an a/c that has, for example, an extended inspection interval on an ALI defined by local CAA contrary to OEMs requirements.
Cheers,
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Grunf,
The guy is talking about MEL/MMEL rectification intervals not OEM inspection criterion!
Personally I think that if a fault can be deferred for 10 days then another 10 probably wouldn't hurt!
The main reason for the addition of a rectification interval is so that the fault actually gets fixed!! The reluctance of airlines to spend money on maintenance is well known (some more than others) so imposing an MEL limit ensures that it is fixed! The MEL time interval is determined (in my airline) as A - (read the remark), B - (3 days), C - (10 days) or D - (120 days) the interval decided as a function of system redundancy, failure rates, increase in crew workload, etc.
My airline has what it has called a RIE (rectification interval extension) agreed with EASA that allows, in the event of a lack of parts or manpower, for the MEL rectification limit to be doubled. It is rarely used but does exist and in my opinion doesn't make the a/c less safe.
The guy is talking about MEL/MMEL rectification intervals not OEM inspection criterion!
Personally I think that if a fault can be deferred for 10 days then another 10 probably wouldn't hurt!
The main reason for the addition of a rectification interval is so that the fault actually gets fixed!! The reluctance of airlines to spend money on maintenance is well known (some more than others) so imposing an MEL limit ensures that it is fixed! The MEL time interval is determined (in my airline) as A - (read the remark), B - (3 days), C - (10 days) or D - (120 days) the interval decided as a function of system redundancy, failure rates, increase in crew workload, etc.
My airline has what it has called a RIE (rectification interval extension) agreed with EASA that allows, in the event of a lack of parts or manpower, for the MEL rectification limit to be doubled. It is rarely used but does exist and in my opinion doesn't make the a/c less safe.
The use of an MEL to give Defect Relief is to acknowledge the removal of a level of safety or reliability from the effected system in your aircraft.
This level of safety or reliability puts (exponentially) a greater safety or reliability risk to the remaining levels of redundancy.
The times quoted in the MEL/MMEL are not plucked from thin air based on the feeling of pilots, but actually worked out using MSG-3 techniques and reliability reports from your airlines/operators, and given the best reliability time that should be tolerated by the remaining levels of redundancy.
Extensions to MEL's should be avoided, however; extensions, consulting the individual aircraft or system's defect reports going back some pre-determined time, may be granted by your AMO or CAM.
This level of safety or reliability puts (exponentially) a greater safety or reliability risk to the remaining levels of redundancy.
The times quoted in the MEL/MMEL are not plucked from thin air based on the feeling of pilots, but actually worked out using MSG-3 techniques and reliability reports from your airlines/operators, and given the best reliability time that should be tolerated by the remaining levels of redundancy.
Extensions to MEL's should be avoided, however; extensions, consulting the individual aircraft or system's defect reports going back some pre-determined time, may be granted by your AMO or CAM.
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Ok, my bad for not reading thoroughly 
BTW, how long can you rectify in order not to reach the OEM set inspection criteria (at least for the structure)?
I do not see CAA capable to give that extensions if the OEM set insepction interval is reached.
I am on the OEM side of setting the inspections but from time to time we get contacted by airlines in order to extend those intervals.
Cheers
BTW, how long can you rectify in order not to reach the OEM set inspection criteria (at least for the structure)?
I do not see CAA capable to give that extensions if the OEM set insepction interval is reached.
I am on the OEM side of setting the inspections but from time to time we get contacted by airlines in order to extend those intervals.
Cheers
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I think you will find that MEL is part of the Approved Flight Manual and as such has been approved by the regulatory agencies. Operation with a defered defect longer than allowed by the MEL would expose the operator to regulatoiry agency action (fines).
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Broken Airplanes
Read the preamble for MELs. The time limits imposed are MAXIMUM time periods...not ETRs (estimated time of repairs). The intent and spirit of the MEL system is to have the plane fixed ASAPractical...with a maximum time limit specified. This philosophy is explicitly stated in the MEL preamble.
Many airlines are government owned/controlled. So, the governments, themselves, can make any rule they want...and it's legal. There is no legal requirement to follow aircraft certification criteria. They make the rules...and it's legal when they come up with 'exceptions' and special cases.
However, not being an aviation lawyer, I can't speak of the legal ramifications through ICAO, international flying, etc., when an airline pulls this nonsense. (Feel free to substitute another eight-letter word, here.)
Most 'real airlines' are governed by state rules that require routine maintenance and repair. This means that the airlines must carry sufficient parts, have a Q/A department to oversee maintenance.
Then, you have Fumbuck Airways, the national airline of Slobokia...where the MEL system is abused to allowed for deferral of routine maintenance (brake on MEL due to wear, is a classic example), or the swopping of a broken part to another aircraft to get another ten days out of the system, or the swopping of a part within a particular aircraft (e.g. IRU 3 inopt...wait ten days...then exchange it with IRU 2...and get another ten days out of the system).
I've seen nonsense where the MEL requires that an aircraft cannot depart a station where repairs can be made. The particular station is the major maintenance base for the airline...and they claim repairs can't be made due to no parts in stock. Again, under the intent and spirit of the aircraft certification (and the associated MMEL system), the airline is 'expected' to have a parts department.
Then, there's the MMEL/MEL issue. Under ICAO and fundamental MEL/aircraft certification regulations, the MEL cannot be any less restrictive than the MMEL. But, at many fly-by-night outfits (government owned and controlled) you'll see otherwise. If you ever get the chance to compare, page by page, the manufacturer's MMEL to your airline's MEL, do it. It may be an enlightening find!
In theory, the aircraft commander is the final safety check point to filter out the nonsense from the safe and legal to go. Unfortunately, and there are legal precedents illustrating this, the commander can be disciplined, sued, sacked, beaten (no kidding!) for carrying out this duty.
PantLoad
Many airlines are government owned/controlled. So, the governments, themselves, can make any rule they want...and it's legal. There is no legal requirement to follow aircraft certification criteria. They make the rules...and it's legal when they come up with 'exceptions' and special cases.
However, not being an aviation lawyer, I can't speak of the legal ramifications through ICAO, international flying, etc., when an airline pulls this nonsense. (Feel free to substitute another eight-letter word, here.)
Most 'real airlines' are governed by state rules that require routine maintenance and repair. This means that the airlines must carry sufficient parts, have a Q/A department to oversee maintenance.
Then, you have Fumbuck Airways, the national airline of Slobokia...where the MEL system is abused to allowed for deferral of routine maintenance (brake on MEL due to wear, is a classic example), or the swopping of a broken part to another aircraft to get another ten days out of the system, or the swopping of a part within a particular aircraft (e.g. IRU 3 inopt...wait ten days...then exchange it with IRU 2...and get another ten days out of the system).
I've seen nonsense where the MEL requires that an aircraft cannot depart a station where repairs can be made. The particular station is the major maintenance base for the airline...and they claim repairs can't be made due to no parts in stock. Again, under the intent and spirit of the aircraft certification (and the associated MMEL system), the airline is 'expected' to have a parts department.
Then, there's the MMEL/MEL issue. Under ICAO and fundamental MEL/aircraft certification regulations, the MEL cannot be any less restrictive than the MMEL. But, at many fly-by-night outfits (government owned and controlled) you'll see otherwise. If you ever get the chance to compare, page by page, the manufacturer's MMEL to your airline's MEL, do it. It may be an enlightening find!
In theory, the aircraft commander is the final safety check point to filter out the nonsense from the safe and legal to go. Unfortunately, and there are legal precedents illustrating this, the commander can be disciplined, sued, sacked, beaten (no kidding!) for carrying out this duty.
PantLoad
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Way back in the annals of time the MEL was simply a 'get-you-home' or to a suitable maintenance base fix, that is all, no extension, but some bean counters have decided that all those spares sitting on the shelves were a waste of money and should be sold off, most spares being available within twenty four hours etc. etc. The rot set in then, IMHO!
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You're Right!!!
Parabellum is totally correct!!!! And, today, that's still the intent of the MEL system.
By the way, for those of you neophytes in aviation, the MEL system changed to what it is today as a result of a fellow named Frank Lorenzo and an airline called Eastern Airlines. (If you remember, their slogan was, "Eastern Airlines...The Wings of Man." But, the reality was, "Eastern Airlines...The Hemorrhoids of Man.")
Way back in the early eighties, gross abuse of the MEL system (as written then) was rampant at Eastern. Everyone in business, including the anti-union U.S. government administration, blamed a guy named Charlie Bryant (Eastern's IAM union chairman) for being a militant union man....claiming that, really, all is well and compliant, and that Charlie was simply trying to fight management in his insistence on compliance with federal aviation laws.
In the end, the result was drastic changes in the MEL system (to put more teeth in to it) and the incarceration of middle-management, maintenance department personnel in the Atlanta federal prison.
To this day, Mr. Lorenzo remains at large!
PantLoad
By the way, for those of you neophytes in aviation, the MEL system changed to what it is today as a result of a fellow named Frank Lorenzo and an airline called Eastern Airlines. (If you remember, their slogan was, "Eastern Airlines...The Wings of Man." But, the reality was, "Eastern Airlines...The Hemorrhoids of Man.")
Way back in the early eighties, gross abuse of the MEL system (as written then) was rampant at Eastern. Everyone in business, including the anti-union U.S. government administration, blamed a guy named Charlie Bryant (Eastern's IAM union chairman) for being a militant union man....claiming that, really, all is well and compliant, and that Charlie was simply trying to fight management in his insistence on compliance with federal aviation laws.
In the end, the result was drastic changes in the MEL system (to put more teeth in to it) and the incarceration of middle-management, maintenance department personnel in the Atlanta federal prison.
To this day, Mr. Lorenzo remains at large!
PantLoad
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Pant Load, the outright abuse of the MEL and DDG as described previous beggars belief. At the end of the day the certifying engineer hase to stand up also. To knowingly swap a u/s part/component into another system is to potentialy reduce what redundancy was left by compromising it also, just to extend the MEL...... That is a big no no
Grounding a/c usually gets the spares delivered and quick!
Grounding a/c usually gets the spares delivered and quick!
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I don't think there are any "if's buts". If he MEL states a item may be defered for X days or X flights and the items is not repaired or replaced within that period the aircraft is being operated illegaly. Speaking for a manfacture our hands were tied on MEL items we could not grant further deferment.
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Well, on my side of the OEM bunch you can grant some extensions but rarely...
I've seen it less then 5 times in the last 10 years...
...and no biggies...
If that is the case (and very often it is) then yoyu can go and break the MEL set time intervals...although, I woul REALLY like to see a CAA telling the airline they can skip on OEM set intervals...
In my experience they ALWAYS consult us, first...ALWAYS...
Lawyers would get rich on that, wouldn't they?
I am aware that local CAA defines "legal operations" but it still has to be inline with ICAO's rules...therefore the possible consequences...
I've seen a few times OEM not wanting to help since the inspection intervals were broken..R&R (remove and replace) was the only solution although airlines were desperate for repairs...and the specific parts were, let's say, "hard to get" (hence the instant wish for a repair)...
I can't imagine how it is to work in lousy legislative surrounding (like the PPruner who posted the topic).
Or we all live in the same <four letter word>...
I've seen it less then 5 times in the last 10 years...
...and no biggies...
...
Many airlines are government owned/controlled. So, the governments, themselves, can make any rule they want...and it's legal. There is no legal requirement to follow aircraft certification criteria. They make the rules...and it's legal when they come up with 'exceptions' and special cases.
Many airlines are government owned/controlled. So, the governments, themselves, can make any rule they want...and it's legal. There is no legal requirement to follow aircraft certification criteria. They make the rules...and it's legal when they come up with 'exceptions' and special cases.
In my experience they ALWAYS consult us, first...ALWAYS...
Lawyers would get rich on that, wouldn't they?
I am aware that local CAA defines "legal operations" but it still has to be inline with ICAO's rules...therefore the possible consequences...
I've seen a few times OEM not wanting to help since the inspection intervals were broken..R&R (remove and replace) was the only solution although airlines were desperate for repairs...and the specific parts were, let's say, "hard to get" (hence the instant wish for a repair)...
I can't imagine how it is to work in lousy legislative surrounding (like the PPruner who posted the topic).
Or we all live in the same <four letter word>...
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[quote=Grunf;2803255]Well, on my side of the OEM bunch you can grant some extensions but rarely...
I've seen it less then 5 times in the last 10 years...
...and no biggies...
I worked in an OEM's Product Support for over 20 years and we could not override the MEL. What we could do is provide the operator with a "No Technical Objection" letter and the operator could approch their regulatory agency. Same holds true AD's the OEM can not over ride the regulatory agency.
I've seen it less then 5 times in the last 10 years...
...and no biggies...
I worked in an OEM's Product Support for over 20 years and we could not override the MEL. What we could do is provide the operator with a "No Technical Objection" letter and the operator could approch their regulatory agency. Same holds true AD's the OEM can not over ride the regulatory agency.
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Well, I stand corrected. In my case there is no direct discussion with the airline, it is up to my group to give the oppinion (based on analysis) if the inspection interval can be extended.
I assume this is the correct course of action (the one GHLCarl explained).
Info and requirements for extensions were comming to us straight from the airlines (telexes or through FSR).
In terms of who can authorize an extension - a DER at OEM can do this (at least for structure which is my turf).Of course it depends whihch level of authority it has.
CAA has no expertise to guve such opinion (at least from what we can see) appart from asking an OEM for opinion.
I assume this is the correct course of action (the one GHLCarl explained).
Info and requirements for extensions were comming to us straight from the airlines (telexes or through FSR).
In terms of who can authorize an extension - a DER at OEM can do this (at least for structure which is my turf).Of course it depends whihch level of authority it has.
CAA has no expertise to guve such opinion (at least from what we can see) appart from asking an OEM for opinion.
