Combi fire suppression

[FlyChuck 3]

The main deck cargo fire arm switch seems to be missing in my vc (744combi). Is there a setting somewhere to get this switch to show?

[downscc 1,327]

The 744M is an odd hybrid, and I recall this being discussed during beta.  The consensus was fire suppression has to cover both all pax and combi configurations, so in some ways it looks more like a pax than freighter.

[Qavion 19]

Looking at my old KLM engineering notes and some Malaysian Airline manuals, I do indeed see a Main Deck Cargo Fire Switch on the Combi :wink: 

 

Normally, full freighters don't have a main deck gaseous (e.g. halon) fire suppression systems (it can be retrofitted, I hear). The cargo fire switch on a full freighter normally just reduces the pressure in the cabin to reduce the oxygen available to the fire. The flight crew then have to put on their oxygen masks. Because a combi has both passengers and cargo on the main deck, it's not a good idea to depressurise the cabin (passenger oxygen doesn't last very long), so the main deck cargo on a combi has a gaseous fire suppression system. This is triggered by the cargo fire switch (after arming the main deck cargo area). Note that the passenger and cargo area is well sealed, to stop the passengers being suffocated by the halon.

 

A bucket-load of fire bottles needs to be added on the combi. As a result, the squib panel on the overhead maintenance panel looks a little like a Christmas tree (Some with 16 lights)

 

The combi is a rare beast indeed.

 

Cheers

John H Watson

[77west 139]

 

 

A bucket-load of fire bottles needs to be added on the combi. As a result, the squib panel on the overhead maintenance panel looks a little like a Christmas tree (Some with 16 lights)
 
The combi is a rare beast indeed.

 

Just look up the SAA 295 and you will see why. Combis are a bad idea and I would feel uncomfortable flying on one, and I don't believe we will ever see a new combi again, with current technology and regs.

 

http://en.wikipedia.org/wiki/South_African_Airways_Flight_295

[phil747fan 14]

Just look up the SAA 295 and you will see why. Combis are a bad idea and I would feel uncomfortable flying on one, and I don't believe we will ever see a new combi again, with current technology and regs.

 

http://en.wikipedia.org/wiki/South_African_Airways_Flight_295

that accident aside combis on the 747 were money maker for many years and of course technologically wise a combi mix of freight and pax ... i enjoyed dispatched combis and luckily never got that kind of drama in our ops ...