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Transponder Inoperative

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Transponder Inoperative

Old 22nd Nov 2011, 10:55
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Join Date: Apr 2010
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Transponder Inoperative

Is there any MEL relief for a total failure of both transponder normally?

I know it should be in the MEL but i don't have a copy and im not working for another few more days.

I did use the "search" function but most talked about TCAS failure.

Not sure if it there a relief for it....no one can see you ...including ATC.

In a busy airport, how are they going to be able to cope with it?

What does it say in your MEL? no despatch?

Many thanks.

Neupielot is offline  
Old 22nd Nov 2011, 11:11
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Without an operating transponder you cannot enter RVSM airspace, the standard Boeing MMEL just states that you are good to go as long as 'operations do not require its use' and that 'prior to flight permission is obtained from the authority'... I remember waiting eight hours to have the transponder panel fixed rather than go fly without an operative transponder system...
STBYRUD is offline  
Old 22nd Nov 2011, 12:04
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Just checked my (european) 737 MEL for that.

Its a B item if both have failed (D if only one has failed), they may be inoperative provided that a) Operations do not require its use and b) prior to a flight approval is obtained from ATC facilities having jurisdiction over the planned route of flight.

That is pretty much an AOG without spelling it out, within europe at least it is impossible to get that approval for anything longer than a hop from one airport to another within the same city. And even that is questionable.

There are three notes to that however.

Note 1 says that an operative ATC Mode S transponder is defined as a transponder which can provide at least elementary surveillance capability (parameter downlink).

Note 2 says that Mode S altitude reporting is required for TCAS operation and if that doesn't work you have to check the MEL about TCAS inop as well.

Note 3 mentions that Mode S altitude reporting is required to enter RVSM and to check the RVSM MEL entry.

The definition in note 1 is pretty prohibitive as even the failure of a databus preventing elementary surveillance will be treated as an inop transponder.
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Old 22nd Nov 2011, 15:52
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basicly you will not get in europe an ifr clearance at all without any transponder so you would be stuck to vfr in uncontrolled airspace.

fo commecial operation its an factual AOG like denti says.
aerobat77 is offline  
Old 24th Nov 2011, 07:40
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Thanks so much guys for your input.
Neupielot is offline  
Old 24th Nov 2011, 18:17
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was doing muscat riyadh flight....just after airborne both transponders failed....muscat put us in a hold over the sea and got us back to muscat, because uae will not except flights without a transponder....even after asking them to check once again, it was a complete no....landed back and grounded the aircraft till the spares arrived late at night and the flight departed with a 16 hour delay...
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Old 25th Nov 2011, 00:24
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Transponder equipment
(a) An operator shall not operate an aeroplane unless it is equipped with:
1. a pressure altitude reporting SSR transponder; and
2. any other SSR transponder capability required for the route being flown.
FE Hoppy is offline  
Old 26th Nov 2011, 08:43
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Transponder equipment
(a) An operator shall not operate an aeroplane unless it is equipped with:
1. a pressure altitude reporting SSR transponder; and
2. any other SSR transponder capability required for the route being flown.
For discussion purposes, "equipped" in this context, debatable ?

The aircraft is equipped with a transponder ( infact 2 transponders), just that they are now inop and therefore it is now MEL-ed. If its allowed in the MEL then it should be allowed to operate?

I think most countries just wont allow you in their airspace without an operating transponder.
Neupielot is offline  

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