B777 - Fire aft cargo scenario with evac

[agg_karan]

Dear All,

B777 - Consider a FIRE AFT CARGO situation in-flight.
Checklist carried out and a/c landed at nearest suitable airport 'as per checklist'

One imp WARNING -

Warning! Inform ground personnel NOT to open any cargo door until all passengers and crew have exited the airplane and fire fighting equipment is nearby.

After landing, the FIRE warning is still active and the CAPT DECIDES TO EVAC. (That is not the question however)

As Per EVAC checklist the a/c is powered down (FIRE SWITCHES APU/ENG pulled), a/c completely DE-POWERED (Only the BAT SWITCH is untouched)

Q1) How will the FIRE HANDLERS/TRUCK personnel or anyone else be able to OPEN the AFT CARGO DOOR with no electrical supply to the a/c?

Q2) I have been given to understand there is a 3/8" tool for manual operation of the AFT CARGO DOOR, will I be correct to assume that this tool won't be available with Fire handlers considering its a very specific tool?

THANKYOU
Above is for academic learning.
Any correction to my assumptions, understanding of the a/c system is welcome.
Answers relating to Q1/2 greatly appreciated.

Regards

[gearlever]

Q1) How will the FIRE HANDLERS/TRUCK personnel or anyone else be able to OPEN the AFT CARGO DOOR with no electrical supply to the a/c?

Regards

Well, it depends.. On most major hubs fire brigades have infra red cameras. If they detect an actual fire they will not open the cargo door. They will ram in a nozzle into the fuselage and spray extinguishing fluid/water.

[rmcdonal]

They will ram in a nozzle into the fuselage and spray extinguishing fluid/water. How does that work? Is there a special nozzle with a sharp edge for punching through the skin, or a separate tool, or do they just get the guy with the biggest muscles and a step ladder onto it? I suppose you could ram it with the tank like fire trucks they have, catering truck can make a hole so I suppose a fire truck shouldn't have an issue.

[gearlever]

Once we had a conference with EDDF fire brigade, where this was told. But can't remember further details.

[Jwscud]

Some (not all) airports have fire trucks equipped with High Reach Extendable Turrets (HRET) with penetrating lances fitted. These can pierce the fuselage and inject foam into the affected area.

A quick Google doesn't give too much detail but we covered the topic in some depth in liaison visits/meetings with the ARFF when I was based at Stansted.

[FullWings]

Seems like a good idea. Opening a hold door will a) let out suppressant (which may still be discharging from the bottles if it was a quick approach) and b) let oxygen in.

I can understand the reluctance to go in there if other methods are available - didn’t know about the piercing lances, interesting!

[Bug Smasher Smasher]

Piercing nozzle & high reach extendable turret - Rosenbauer (http://www.rosenbauer.com/en/au/rosenbauer-world/products/fire-fighting-systems/stinger.html)

[bigduke6]

Can also poke a non-piercing nozzle through the negative pressure doors on the cargo door.

[CBinPIT]

Piercing nozzles are often a part of the airport crash truck and can be extended from there, but they are also available for hand lines and could be used that way:

Piercing Applicator (http://www.akronbrass.com/piercing-applicator)

Even regular (non-airport) fire departments carry these to get into areas that you might not want to enter like car fires, basement fires, concealed areas, etc.

[agg_karan]

FAA research has clearly demonstrated the effectiveness of using an HRET to aggressively fight an interior fire and increase occupant survivability. AC 150/5210-23 provides guidance on the use of HRETs and states that testing has shown that an HRET with a skin-penetrating nozzle can control and contain fire from spreading, reduce high cabin temperatures, and provide rapid smoke ventilation. Although the AC provides information on how and where to pierce an airplane, it does not include any guidance to firefighters on when to pierce.

Came across the above :)

Didn't know about the infrared option.

I was under the impression HRETs are used only for cabin fires and not cargo, however that's not true.

In the ASIANA crash as well HRET's were used.

Thanks all for all your time and effort.