Qxeguy From United States of America, joined Nov 2003, 81 posts, RR: 0 Reply 1, posted (8 years 7 months 2 weeks 5 days 11 hours ago) and read 3501 times:
I don't have the regs in front of me...but they are all in the FARs. Depends if it is a part 91, part 135, or part 121 operation. I will assume part 91 for your question, because that is what I deal with the most.
First, does the Aircraft have a Minimum Equipment List? (list of stuff that is allowed to be broken, blessed by the FAA). If the broken item is on the list, and meets the conditions set forth on the list then you can fly.)(I have heard about Airliners having to ground aircraft because a toilet door latch is broken because the the door latch is NOT on an MEL, and they couldn't get it fixed in time)
If it doesn't have an MEL, the answer must be NO to all of the following questions:
Is the broken item...
Addressed with an Airworthiness Directive? (The aviation equivalent of a Recall)
Required for the Type of Operation. (Reference the Operating Handbook equipment list to see if it is required)
Required equipment for VFR, VFR Night, or IFR operations (Part 91 dot 200 something (again, I don't have the regs in front of me. These items are commonly referred to by their pneumonic devices as TOMATOFLAMES (VFR Day), FLAPS (VFR Night), and GRABCARD (IFR))
Finally ask yourself, is the broken device going to affect the Safety of Flight
I hope this helps. Sorry I didn't have the exact reg references in front of me, but I didn't want to accidently cite the wrong one.
I fly boxes. Boxes don't bitch. Boxes don't barf. Boxes don't get drunk and do a number 2 on the beverage cart.
EMBQA From United States of America, joined Oct 2003, 9348 posts, RR: 12 Reply 3, posted (8 years 7 months 2 weeks 5 days 11 hours ago) and read 3453 times:
MEL is your friend..!!!
Yes, you can defer items that are not working or are defective. It depends on what the item is, how it effects airworthyness and other systems. Then it is broken down into how long you can defer it. Cat A being the shortest...Cat D being the longest.
"It's not the size of the dog in the fight, but the size of the fight in the dog"
Air2gxs From , joined Dec 1969, posts, RR: Reply 7, posted (8 years 7 months 2 weeks 5 days 6 hours ago) and read 3244 times:
The airline derives its MEL from the master MEL developed by the manufacturer in accordance with FAA regulations. The operator can be more restrictive than the MMEL but can not be more liberal without authorization from the manufacturer.
The MEL carries hudreds of items. They usually pertain to redundant systems (generators, smoke detectors, communications) or non safety of flight items (APU, lavs). Now some items being deferred carry restrictions. An APU being deferred may restrict an ETOPS certified aircraft from operating in an ETOPS environment or a CAT certified aircraft from operating at CATIIIb limits (due to the APU generator being unavailable).
There is also another book out there called the Configuration Deviation List (CDL). This allows the aircraft to operate without certain external parts. These include but are not limited to access panels, flight control seals, gear doors, fairings, etc. There is usually a performance penalty applied to these missing parts.
MD11Engineer From Germany, joined Oct 2003, 13602 posts, RR: 63 Reply 9, posted (8 years 7 months 2 weeks 5 days 4 hours ago) and read 3180 times:
And even if it is not in the MEL or CDL, you can sometimes still dispatch the plane under an engineering order ( done this once for a freighter, when we didnÂ´t have the spare in stock. They let it fly three days to reach home home).
Abbs380 From United States of America, joined Mar 2005, 120 posts, RR: 0 Reply 10, posted (8 years 7 months 2 weeks 4 days 21 hours ago) and read 3100 times:
MD11Engineer, yes this is not rare, had to do it several times myself. Last time was when an eyeball vent blew apart on t/o. This was on a 727, Capt thought his window blew open because of the noise, did a rto. Vent was not in mel, so got an EA to plug the air supply hose and sent them back out.
HAWK21M From India, joined Jan 2001, 31457 posts, RR: 57 Reply 11, posted (8 years 7 months 2 weeks 4 days 20 hours ago) and read 3083 times:
Out here the word "Broken" means Made into pieces.We use the word "U/S" or Unserviceable.
MEL [Minimum Equipment list] is a document issued by the Civil Aviation Department,containing units & System pertaining to an Aircraft,that may be Inoperative for a limited period of time without adversly affecting the Safety & Airworthiness of the Aircraft.
CDL [Configuration Deviation List] covers missing External parts like panels etc.
DDG [Despatch Deviation Guide] gives Instructions to the Pilot [Operational procedures] & AME [Maintenance Procedures] on method followed to despatch a particular Aircraft under MEL & any instructions to be followed/Any Penalties occuring.
MEL cannot be less restrictive than the Master MEL [MMEL] which is prepared by the Manufacturer.
This Does not Involve Wings,Langing gears,Engines that are critical to Aircraft operations,neighter covers Seat Covers etc that do not affect Airworthiness.
Even if an Item is covered under MEL,the Pilot can refuse the Aircraft or the AME can refuse to clear the item under MEL if its felt Unsafe to do so.
My friends at the Airport often tell me because of my Name that,an Aircraft will always flying with you around because of M.E.L.
I wish it was that way.
Saintsman From United Kingdom, joined Mar 2002, 2065 posts, RR: 2 Reply 13, posted (8 years 7 months 2 weeks 4 days 15 hours ago) and read 3040 times:
It is quite common for broken items to be deferred until a suitable oportunity to be repaired. Some of these items can be years away.
Say, for example, an anchor nut is broken on a floor panel. To repair it will mean that the seats will have to come out, the carpet taken up and the panel raised. Provided the remaining anchor nuts are doing their job and that there are no safety implications, then the repair would be deferred to a more convenient time - maybe the next time the floor panel was due to be raised.
Think how long it would take to carry out the repair. Does it make sense to ground the aircraft for four hours or so just to replace a small anchor nut? That is why things are allowed to be deferred until later, although they are not done on a whim. As has been mentioned, there are guidelines as to what you can and cannot defer.
777WT From United States of America, joined Jan 2005, 874 posts, RR: 1 Reply 14, posted (8 years 7 months 2 weeks 4 days 14 hours ago) and read 3025 times:
Just like one of the show on Airliners on A&E with SWA
A flight was due to depart and during pushback the pilots finds the anti-ice bleed valve isn't working, they were figuring out if they could MEL it. Nope they couldn't because the flight is going to be flying in known icing conditions, so they had a tech come out and replace the anti-ice bleed valve in the right wing.
HAWK21M From India, joined Jan 2001, 31457 posts, RR: 57 Reply 16, posted (8 years 7 months 2 weeks 3 days ago) and read 2878 times:
Quoting Starlionblue (Reply 15): Quoting AirWillie6475 (Reply 5):
There was a program about this some time ago that said that united for example, used tape to cover some loose parts of the wing. Hey it makes sense right?
Air2gxs From , joined Dec 1969, posts, RR: Reply 18, posted (8 years 7 months 1 week 5 days 10 hours ago) and read 2753 times:
Quoting LongHorn2000 (Reply 17): flew from MSP to AUS on a NW DC-9 w/ the APU out of service. That was a little much for me. I'd rather have a delay and a working APU.
Why is this? An APU on a DC9 is not even remotely a flight safety item. It is a convienance item. If the weather is at extremes, then an aircart or airconditioning cart should have been connected. An aircart would have been connected for start anyway.
LongHorn2000 From United States of America, joined May 2005, 12 posts, RR: 0 Reply 19, posted (8 years 7 months 1 week 5 days 3 hours ago) and read 2716 times:
Air2gxs: In response, was it a real safety issue, probably not. It is unlikely, but it could have become one though. Both engines serve as generators, and if they are both lost, then there is no power generation at all. Unless the 'ol DC-9's were equipped with some sort of ram air device like the newer jets are.
The pilot even explained why he was flipping from one generator to the next while we were at the gate (as there were an excessive amount of ding noises in the cabin).
OPNLguy From , joined Dec 1969, posts, RR: Reply 21, posted (8 years 7 months 1 week 4 days 23 hours ago) and read 2684 times:
Quoting VC-10 (Reply 20): What are the odds of loosing both gens at the same time? If that did happen there are still the batteries that would last long enough to get back on the ground
It did happen once, sort of... Back in 1983, Air Illinois 710, a HS-748 took off and 90 seconds later failed a generator. The F/O disconnected the wrong CSD, and with no APU installed, they were then on a :38 minute flight with a :30 NiCad battery. All this is at night, mind you, with destination IMC with rainshowers and embedded thunderstorms in the area. As you might expect, they exhausted the battery short of the destination, and all aboard were lost in the ensuing crash.
HAWK21M From India, joined Jan 2001, 31457 posts, RR: 57 Reply 22, posted (8 years 7 months 1 week 4 days 20 hours ago) and read 2665 times:
Quoting OPNLguy (Reply 21): The F/O disconnected the wrong CSD, and with no APU installed, they were then on a :38 minute flight with a :30 NiCad battery
Still did not loose both Gens due to Mechanical defect,this was Pilot error.
Ar Sahara had a U/S APU & lost both the Generators sometime on their B732s in 1997,if not wrong.
The cause was a Shorting wire.
It landed on Battery power.
LongHorn2000 From United States of America, joined May 2005, 12 posts, RR: 0 Reply 23, posted (8 years 7 months 1 week 4 days 10 hours ago) and read 2618 times:
Air2gxs, I am involved enough with A/C design to know that there is no way a designer would allow the weight of an APU system on an airplane just to enable air conditioning on the ground.
VC-10, The pilot's explanation of why he was switching from one generator to the next was that he was double checking his back up because the APU was not working (and the APU is a second back up). It is highly unlikely that both engines would be lost, but if they were, I would rather have an APU than a battery.
I might add that any airline accident is highly unlikely, but they do happen, and they generally occur because of a chain of events. Having no APU could easily be a part of that chain.
Air2gxs From , joined Dec 1969, posts, RR: Reply 24, posted (8 years 7 months 1 week 4 days 3 hours ago) and read 2576 times:
Quoting LongHorn2000 (Reply 23): Air2gxs, I am involved enough with A/C design to know that there is no way a designer would allow the weight of an APU system on an airplane just to enable air conditioning on the ground
You're absolutely right. An APU is also used to supply electrics on the ground, pnuematics on the ground and supply air for main engine start.
Question, having never worked the DC9 series aircraft, is the APU in-flight start/operation certified?
On more modern aircraft the APU is also used as an back-up power supply in the air in the event of an IDG failure. It also serves as a back-up for pnuematics. It is still not a flight safety item.
My point, quite simply, is that an inoperative APU, especially on older aircraft, is no reason to take a dely. Newer aircraft will have restrictions placed on them with the loss of an APU, but still no reason to take a delay.
25 Sideflare75: Yes it is. If one of the engine CSD/Generators is deferred then the APU is used in flight to provide the second generator. There is an altitude limit
26 HAWK21M: Is it Altitude restriced for reasons of unable to sustain Pneumatic load or just designed that way. regds MEL
27 Sideflare75: I'm assuming the altitude restriction is because it can't keep running at 100% power in the thinner air. Like I said the DC-9/MD-80 apu does not suppl
28 HAWK21M: Because there should be an Altitude limit beyond which Pneumatics cannot be used in Air.So I found it surprising. regds MEL
29 CitationJet: I just found a link to European JAA MMEL for some aircraft: http://www.jaa.nl/operations/secured/mmel/mmels.html The list includes Boeing and Airbus a