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caulfield
4th Jul 2008, 17:13
B737-400 passenger aircraft.Cargo fire detection/suppression system is deactivated.According to MEL,can you dispatch and with what
restrictions?Thanks in advance for your help.

RobinR200
4th Jul 2008, 19:06
flight without cargo?

Capt Chambo
5th Jul 2008, 02:25
It's been a while since I flew the B737-400 but I seem to recall they came without a cargo fire detection system as fitted to the -NGs. Instead the holds were designed to suppress a fire for 30(?) mins. (I think they were called class D holds).
The lining of the holds had to be intact as this is what provided the suppressant, any tears or damage had to be fixed using a fire retardent tape. If the hold could not be repaired I seem to recall we could continue to use the hold provided no flammable items were carried in that hold. Obviously all the limitations and specifics were incorporated in the wording of the MEL, which would have been specific to the company I was working for at the time.

Checkboard
5th Jul 2008, 10:43
That's right - each compartment in an aircraft is classified from A to E, i think. The classifications depend on the access to the compartment, and its ability to withstand a fire - so the cabin is A, with full access (and full-time supervision by FAs) the toilet is B (doesn't have full time supervision) etc.

The cargo compartment on the classics were Class D compartments, no access in flight, so fully able to contain a fire.

However!
As a result of the 1996 Valujet accident, the United States Federal Aviation Regulations Sec 121.314(c) require that after March 19, 2001, each class D cargo compartment must meet the requirements of FAR 25.857(c) and FAR 25,858 for class C cargo compartments and all cargo operation aircraft may have the class D compartments meet the requirements of FAR 25.857(e) for class E.

As to the MEL provision, I don't have a classic MEL anymore!

Nightrider
5th Jul 2008, 16:39
MEL 26-19 is same as for -800 now, there are several items like the loops, detection / suppression system, bottles, etc.
If the system itself is u/s than it is timeframe "C" and
May be inoperative provided associated compartment remains empty.

NOTE 1: Does not preclude the carriage of empty cargo containers, pallets, ballast or cargo restraint components.

NOTE 2: Class E cargo compartments require only the installation of smoke or fire detection systems (not suppression).

john_tullamarine
6th Jul 2008, 23:14
Several references to MELs here.

Keep in mind that an operator's MEL will be based on a master document .. often the FAA MMEL, found at the OpsSpec (http://www.opspecs.com/AFSDATA/MMELs/Final/transport/) website. A specific MEL may well be more conservative but ought not to be less conservative ...