Bombs away!
 

Fires in cargo? Simple.

Create "bomb door" compartmentalized storage units each with it's own bay, and simply pull the lever. The loss of some baggage is expected and a small sacrifice for saving lives. With the main conflagration gone, it would also be simpler to address the incidences of crossover into adjacent units, as now there is working room. The technical issues would need to be ironed out. It would call for a redesign of new aircraft of course.

So a pallet smashes through a school and kills 30 kindergartners?

JNB,

Might be better than "throwing" the whole plane and burning cargo at them!

OP

There's a lot more to cargo jettison than it looks like.

GF

Is it? Ever dealt with an onboard fire?

What class of compartment? Do you know how fires are handled presently?

Simple, you say?

At what weight gain for the aircraft? With what altitude and airspeed and configuration limitations?

With what changes to the center of gravity? Every kicked heavy loads off an aircraft in flight with massive weight and balance changes? I have. I do regularly. There are aircraft control issues among other things.

With separate fireproof compartments, aside from the aircraft complexity and weight gain for the doors and compartmentalization, each segment would require its own door, with considerable changes and weight gain to the structure, just to load the cargo. Very quickly, no need for cargo, because the weight that could have been carried is now structural...to what end?

You're aware that presently there are more than one cargo area, and depending on the class, have multiple means of addressing a fire including smoke routing, smoke detection, fire detection, fire suppression, depressurization, and other means of detecting and addressing a potential fire?

Surely not large burlap wrapped bales... 🙄

Kidding aside. I agree that this is a ridiculous idea.

I have no idea, but they say every change has a beginning. The current system can't ensure safety, and is designed to getting everything crammed in as quick as possible. The baggage people although diligent in their work, cannot be expected to scan for every condition that is a potential for chemical or spontaneous combustion.

I think it was the FEDEX flight into Dubai that is a good incentive for bay re-design(lithium batteries I recall). As a result of this horrific case, they tried and tested new designs of fireproof containers. No answer was found to the problem.

The flight issues you mention can be handled in training on the newly designed model. But we are speaking of exceptions, not the rule. Perhaps the experiences of Lancaster
aircraft could be incorporated. I believe they would have experienced the extremes and know the effects. I think the bays loaded to 5 tons, can't be sure.

The Air Force could be involved in the design as well using technology of the transports, etc.

Of course.

...And the odds are?

I looked at your profile and you didn't list any aircraft design/engineering background. If you can cite some real ideas, we'd be pleased listen, but right now you are an unknown.

I have a lot of time in military transports who have inherent jettison (airdrop) provisions--cargo fires were addressed with Halon flooding, large extinguishers or depressurization before any thought of jettison.

GF

It was already a given that you have no idea what you're talking about. No need to go out of your way to make it glaringly obvious.

The USAF doesnt design aircraft. See the former response.

That you're on the ignore list? 100%.

Brook no trolls.

We dont do odds, any more than we guess. We know.

You don't.

Structural weight & complexity to accommodate jettison system?

Additional systems to execute the jettison?

CG change? To minimize this you would need multiple selective jettison bays...$$$$

You could really only jettison over water or perhaps severely uninhabited areas. FAA would not approve otherwise.

Depressurization?

Not the answer, by a long shot.

Depressurization is the answer for certain classes of compartments and some fires.

Bring the cabin to 25,000' works, in some cases. Last ditch for sure.

GF

I meant jettisoning cargo is not the answer. Depressurization would have to be part of that. That might put the fire out but then you have to decide whether to stay high to keep the fire suppressed or descend to land. If you're over water, might as well stay high I guess at least until your O2 runs out.

Might not save you from a box of lithium batteries.

Why not start by just actually putting robust main deck fire suppression systems on board?

Jettison :rolleyes: issues aside, the problem with main deck suppression isn't an easy one. The main issue is that the crew effectively inhabits the "main deck" along with the cargo. There is no way to seal off the main deck. On the 777F, we can even have a cockpit door due to depressurization airflow/air-load issues on the aircraft structure during a rapid-D. Trying to seal the main deck cargo compartment to allow a suppression agent to be effective (like the lower class-E compartments) isn't feasible.

Fedex has installed an after market main deck FSS. It uses an array of sensors for the main deck positions and a bayonet system which pierces the metal cans and injects an argon based foam or in the case of a pallet, lays down the foam on the pallet. Certainly better the the basic aircraft option (depressurization and main deck airflow control). There was at least one false alarm that didn't pierce the can because the can roof was defective and not rigid enough for the bayonet to puncture. It's also ineffective against a sustained LI battery fire as are all currently available FS agents.

Back to the depressurization thing for a sec. The best option for fighting an in-flight fire is landing withing 15 minutes. The Boeing depressurization for a main deck smoke warning is only going to be used if you're ONLY option is to spend time at altitude due to the proximity of available airports. That portion of the checklist is going to be skipped right over if the aircraft is anywhere over the continental US or anywhere else with easy access to concrete. The other time I'll skip that option is if I know we've got a sustained LI battery involved fire and I'm not within 15-20 min of a runway. Then it's an off airport landing in a remote area or controlled ditch.

Or this.

Engineer Designs Cabin That Can Detach Itself From An Aircraft In An Emergency | IFLScience

Take notice which part of the plane stays attached. FU commie engineer.

Gives the pax guys some options with a takeover attempt or maybe just an unruly bunch in the back.

"Ladies and Gentleman, this is your Captain. You have two choices. Kill or if possible restrain the idiots threatening the cockpit and let me know when you're done or I'm going to jettison the whole lot of you. That is all." :D

"The cabin’s design also includes storage space, so cargo and passenger luggage as remains safe, The Independent reports."

Thank heaven the luggage is safe!

Give me one reason why lithium batteries can't exclusively be transported by truck, rail or boat.

..........$ :mad:

Can't be, or aren't? Economics.

I entered the main deck once to find that it was container after container of lithium batteries. I looked into the containers and found they were stacked two pallets high with cases of lithium batteries. Each pallet had a large sticker that stated "do not stack." I refused the shipment and required that half the pallets were removed. The company and shipper were upset, to say the least. I took pictures and forwarded them. Next time a shipment came up, the labels were removed.

The C-5A models had 1300# of FE1301 in 26 bottles (IIRC) to flood the cargo with basically halon. Whether it was ever used, I can't say, but it was removed from the B-models. I would guess firing that much halon would kill any fires; occupants would probably need O2 until the cabin was ventilated.

GF

Well, they might catch on fire for one! :p

We (Fx 777) were having this conversation mid-Pacific last month. Main deck fire checklist has you stay at fl250 unpressurized until near airport, could be hours. Recent tri-annual cbt training said that with cargo fire, history shows you have at max, 20 minutes to live. Kinda doesn't jibe. You make a distinction in your post between cargo fire and lithium battery fire--how do you know what you have? Book says don't go look.
Based on onboard fire history (20 minutes max till game over), would the prudent thing be to descend to 1000'agl - no matter where you are, and prepare for ditching/highway/dry lake bed landing? I don't think I want to be at fl250, hoping the fire is going to starve (not possible with lithium) when the 20 minute timer runs out..
Thoughts?

Surface transport is the solution. Once the supply pipeline is established, the "need" for air transport is obviated.

I claim no expertise in fire fighting game plans. Only what I've thought of (after the occasional post nightmare shakes) or crew discussions as you mentioned.

I do make a note of LI battery locations during pre flight. So, I would at least know if they were on board or not. Depending on which system was alerting me, I may be able to identify a specific position(s) involved with the fire and have some idea of whether LI batteries were involved or not. Not much can be done about the possibility of undeclared DG, but we have to start somewhere.

In the absence of known LI batteries, I think I would be more inclined to roll the dice and let the low O2 suppression option on the main deck and/or lower cargo class-E compartments suppression agent get me to a suitable field. I'd caveat that with the fact that I'm damn sure gonna go back and do my best to assess he situation regardless of what the book says. I think the "book" might be saying going back to fight the fire isn't the best options. Going back to look? That seems kind of critical to me. Especially if I need to determine if what I've done so far (main deck suppression/FSS) appears to be working. I've got the rest of my life to figure out the nature of the fire and if it warrants a water or off-field landing. That's a pretty big decision to make blindly when additional info might be fairly easy to obtain.

One went below in UPS 6 to have a look. He never came back.

All good points. But if you are going to roll the dice/bet your life on the low O2 suppression route, wouldn't it be better to climb as high as you can go (MAX ALT) rather than FL250? Sure, there are possible physio problems unpressurized at the higher altitude, but versus burning up....

My question is what is the harm in an immediate descent to 1000 agl, and investigate/fight fire there? Fuel shouldn't be an issue because you are going to probably know your fate in less than 30 minutes. If it's not good, you're ready to ditch; if it is good, then you can climb again and you've only spent 30 minutes down low. The only harm I see is the O2 levels at 1000' vs fl250- not a fire expert, so I don't know the effect. But the RFO with a halon bottle is probably better (again, against the book) than thinner O2.

I can't remember what kind of vvi you get in a 777 during high speed descent but would guess around 5000'/min. So a ditching decision made at Fl250 is at least 5 mins away, or 25% of your remaining lifetime. If the decision to ditch starts later in the 20 minute lifetime, then its 100% of your remaining lifetime:(

I don't have the answer, I just noticed the discrepancy from the cbt training and have been asking others what they think...

I'm not certain if you're making reference to a LI battery fire specifically or any in-flight fire warning.
I'm not sure about this. I would suggest getting more information on the system and logic behind it's design. The 777 still maintains some measure of positive differential with a main deck smoke warning and depressurization scenario (25K altitude w/ 23K cabin altitude). I'm not sure if those altitudes were selected ONLY to deal with potential physiological issues with the crew in a depressurized situation or if there are other factors at play. There may be some unintended consequences by attempting to deviate from the QRC procedure. The pack configurations during a main deck smoke event attempt to keep positive pressure to the flight deck and hopefully minimize smoke aft of the flight deck flowing forward. With one pack off and the other in low flow to accomplish this, climbing above what is recommended by the checklist may defeat what the system and checklist have been designed to accomplish. Though, as I said, I'm not certain of that.

To your other points:
Not sure if you're advocating the descent plan with any fire warning or something specifically tied to LI batteries known to be involved. If I am hours away from a suitable field, an off airport landing or ditch decision isn't going to be my starting plan. I would advocate an attempt to gather as much information as possible about the situation before considering those options. The lower cargo compartments are designed to buy some time and have the best chance (IMO) of successfully suppressing a fire while we get to a suitable field. Perhaps the main deck FSS in combination with the "factory" system using depressurizing/airflow control is working as advertised. Maybe the position involved has the fire retardant bags (make a point of asking if you don't - they're used regularly).

Because of the nature of the LI battery threat specifically, I will probably be less likely to rely on our current suppression methods if I'm certain they're involved. Either way, if we can determine the situation is deteriorating or already out of control, I think your plan to head for the deck and prepare for more bad stuff makes some sense.

One other tidbit I recently learned. UPS is fielding ceramic cans that can contain a LI battery fire for 4 hours. As an added bonus, they are significantly lighter than the metal ones we currently use. Next time I come out of SIN with the typical load of 6K+ lbs of LI batteries, I'd sure feel better if they were in those UPS cans.

Great discussion.

I know the FAA Tech Center (In ACY) does active research on the things you are discussing. Also, CAMI (In OKC at the MMAC) does the human factor and physiological research.

https://www.fire.tc.faa.gov/systems.asp

At this point, does this become an issue determined by cost vs risk for operators?

See? The labels were removed! no problem then, right? :D

As for the original question of making a "bomb door" or I'm guessing a B-29 like bomb bay.

Initial answer is: no

After some thought: HELL no!

Ok, let's go through the time and expense to make a set bomb bay doors on , say, a B747. Doors on a pressurized system are expensive, heavy (meaning less cargo weight meaning expensive), and more complexity (more expensive) and more maintenance and inspections ($$) and no guarantee of success.

Also, we haven't considered how to evacuate the main deck cargo.

It took the 2001 terrorist attacks to get solid cockpit doors on airplanes.
Cargo drop doors will NEVER HAPPEN (in standard cargo airlines).

Another consideration:
No one cares about cargo planes crashing.
Ok, not "no one" but it doesn't have the emotional response that passenger planes have.

An airplane crashed
people: "oh my, that's horrible!"
A cargo plane
people: "bummer, any pictures?

So instead there are mitigation procedures:
Hazmat laws, checks, as mentioned above: knowing where the bad cargo is to make it easier to fight.

Can't fight the fire?
Get on the ground/water pronto.
Unless it's mountainous (you're screwed)... or arctic waters (just as screwed), hostile territory (ooh, yeah, that's a good time), densely populated (screwed with innocents).

Makes me slightly depressed but no more surprised that there are people like yourself who exist in the world. :rolleyes:

At least it sparked a good discussion.