Carbon dioxide fuel tank fire extinguishers for aircraft

[Teh0 294]

I don't know if this should instead have been a bugreport of a lacking feature, but lets start this way. It could help me to add new aircraft into the list which used this and more details about the system itself.

 

This is a system, which surprisingly few seem to have heard about. From what I know it was employed solely by Imperial Japan into their late fighter types. It is not certain why only them, but I would suggest it could be because wast majority of aircraft they faced, were armed with .50cal, a gun which relied more to igniting fuel fires than 20mm cannons. Don't forget most Japanese fighters had very high fuel capacity, so the tanks also offered a larger vulnerable area.

 

So how does it work and what does it do? The system has CO₂ tanks situated in the rear fuselage and piping around the fuel tanks and behind engine to spray the CO₂ to almost instantly put out a fire. In initial versions the pilot used a switch to choose which tank to extinguish, but later a thermostat did it automatically. There are however downsides after the use of this system: The CO₂ foam makes the fuel tank inoperable. The damaged tank would still continue leaking, but igniting it again properly would be very difficult due to the foam. This reveals us another reason why only Japanese used this system late in the war: Many of their fighters had one or two fuel tanks in the fuselage and one in each wing. When flying short range interception missions, it wasn't as much of a burden to have one of multiple fuel tanks off.

 

A list of planes which are known to have had this system. It was mostly a IJN thing, maybe because IJA protected their planes otherwise better:

• A6M5 and all following A6M variants
• A7M1, A7M2
• N1K1-J, N1K2-J, N1K2-Ja
• J2M3, J2M5
• J5N1
• J6K1
• Kikka
• H8K2, H8K3
• D4Y2
• B6N2, B6N2a
• P1Y1
• Ki-67
• Ki-61-I Hei and following Ki-61 variants (not certain about these)
• Ki-100 (uncertain)

 

Mitsubishi's approach to fuel tank protection was quite radical in J2M and A7M. Their fuselage tanks had possibly the thickest rubber coating in single seat fighters of their time. Meanwhile their wing tanks had no selfsealing protection at all and relied solely on the CO₂ extinguishers.

 

Automatic fire extinguishers in action.

 

N1K2-J fire extinguisher system

Spoiler

 

"Operational japan fighters. Intelligence summary no. 283-4 August, supplement." https://cgsc.contentdm.oclc.org/digital/collection/p4013coll8/id/4666

Americans note the existence of CO₂ extinguisher system in "Jack II", which means J2M3.

Spoiler

 

Kawasaki Ki-61 Hien / Ki-100 (Monographs) by Leszek A. Wieliczko

This is one of the most detailed English books about Ki-61 and Ki-100. According to this the system was added first into Ki-61-I Hei and remained in all the later variants.

Spoiler

 

https://dl.ndl.go.jp/info:ndljp/pid/4009538 page 21

Spoiler

 

page 28

Spoiler

 

To me it seems like an important feature, which was central part of protection for several aircraft. Such thing should not be left out of the game. In game it would certainly not be any shield generator. It would be at it's best against those infamous 1km away .50cal hosers, while against a 20mm burst from meager 300 meters it would not make much difference. A larger multi engine plane could possibly benefit more from the system, but for now I am not certain if it was ever implemented in such aircraft.

 

The game has even had a somewhat similar fuel tank protection system for years: Neutral gas pressurization system in many Soviet WWII era combat aircraft. It was likewise intended to provide additional protection to fuel tanks, but instead of actively putting out flames, it was a passive system to make the tanks less flammable. I do not know how it exactly works in game, though I would like to if anyone can help with that matter.

 

Lagg-3-8 one of the first aircraft you can meet with this system. It must an important working feature, since it has been around so many years in game and is also included in Tu-1, which was added few months ago.

Spoiler

 

Edited September 17, 2022 by Teh0

[super_cacti 1,071]

Open for discussion 

 

Edited the title slighty to better explain the idea

[pancake_addict 196]

Would be nice to have it in game 

[EddieVanHalo@live 880]

Why go to all that trouble in an arcade shooter where Japanese Zeros battle German Biplanes And Spitfires etc etc in the same battle ? 

 

Its just a shoot em up .The game does not embrace or sustain reality. It goes all out to create realistic models but that realism dies as soon as the battle takes place  because those aircraft do no fight against the very things they were designed to face and counter.Might as well all use the same plane really ,the outcome would be no different .  

[Lavo 132]

Given how essential it was for certain aircraft, in particular ones which have a slight propensity for catching aflame, such a system was made in part to address that specific weakness and excluding it from the game would be a loss.

[Sarp19o3 19]

greate idea it should be added to modern planes too 

[Teh0 294]

Finally the game is receiving engine fire extinguishers, so it's time to start updating this suggestion. Any data about fuel tank fire extinguishers is welcome.
https://warthunder.com/en/news/7830-development-aircraft-engine-fire-extinguishers-en

[_qaz_ 675]

It's weird that they are only adding engine extinguishers. I think all types should be added.

 

At the moment, in terms of fighters, I think only Shiden will benefit from this, as it has a manual engine extinguishment system in addition to the automatic tank extinguishers.

A6M5, Raiden, and Kikka I believe only have automatic fuel tank extinguishers. Reppuu, I am not sure.

[LeChance 926]

This poll is worded very oddly . . .  you "pre-qualify" anyone's answer into a very narrow parameter. I am of the "wait & see" school of thought on this. It sounds ok, looks good on paper, but really want to see actual in game performance of this "modification". And questions, will this "unspade" all of my aircraft?, is this going to be just useful for multi-engine planes only? Adding modifications late in the game is kinda . . . .  odd as well. Just wondering about it . . . can I kill bombers twice now?? . . .. lol . .  sorry, I could not resist that one . ..

[Teh0 294]

1 hour ago, LeChance said:

This poll is worded very oddly . . .  you "pre-qualify" anyone's answer into a very narrow parameter. I am of the "wait & see" school of thought on this. It sounds ok, looks good on paper, but really want to see actual in game performance of this "modification". And questions, will this "unspade" all of my aircraft?, is this going to be just useful for multi-engine planes only? Adding modifications late in the game is kinda . . . .  odd as well. Just wondering about it . . . can I kill bombers twice now?? . . .. lol . .  sorry, I could not resist that one . ..

The engine fire extinguisher was shown as a late tier modification on the video, so most certainly it has to be researched.

Edited August 25, 2022 by Teh0

[Noveos_Republic 503]

On 25/08/2022 at 14:48, _qaz_ said:

It's weird that they are only adding engine extinguishers. I think all types should be added.

 

At the moment, in terms of fighters, I think only Shiden will benefit from this, as it has a manual engine extinguishment system in addition to the automatic tank extinguishers.

A6M5, Raiden, and Kikka I believe only have automatic fuel tank extinguishers. Reppuu, I am not sure.

I thought the CO2 extinguishers were engine extinguishers

[_qaz_ 675]

39 minutes ago, Noveos_Republic said:

I thought the CO2 extinguishers were engine extinguishers

 

It can be if the piping is set up in that manner. In Shiden there are three bottles, one for each wing, and another for the fuselage tanks. These are all controlled automatically by temperature sensors. However, piping from the bottle for the fuselage also has a second channel extending to the methanol tank and engine, without sensors. These parts can be manually extinguished by the pilot via a lever in the cockpit.

 

From the document provided in the OP of this post, A6M5 only has two bottles, probably one for each wing's tanks. This lines up with the existing data that only A6M5s wing tanks are protected by the automatic fire extinguisher.

 

Meanwhile, Raiden has three bottles like Shiden. One will be for the fuselage fuel tanks, and it's possible that the piping also extends to the methanol tank and/or engine like Shiden, but it's hard to know without seeing a schematic of the system, or some source mentioning it. More investigation is necessary.

[_qaz_ 675]

From 'Japanese Navy Interceptor Fighter Raiden' by Model Art

 

Up to J2M3 #53, Raiden had a manual engine extinguisher, with one Model 4 CO2 bottle:

 

 

Starting with J2M3 #54, the engine extinguisher was removed, and Raiden had automatic extinguishers added to the fuel tank of each wing, using two Model 4 or Model 4 Kai CO2 bottles:

 

So according to this book, Raiden first had only a manual engine extinguisher, and later, only auto extinguishers in both wing tanks. Just like the Zero.

 

..

But according to the translated JP document in the OP, Raiden was recorded as having three Mod.4 Kai CO2 bottles. Furthermore, in the US document concerning Raiden in the OP, it says the fuselage fuel tank is also protected. So perhaps even later, a third CO2 bottle was added, and automatic extinguisher was added to the fuselage fuel tank. Whether it also extends to the engine like Shiden, perhaps not (I would think it would be stated), but this is only a theory assuming both documents aren't erroneous.

Edited August 29, 2022 by _qaz_

[Milocat 4,850]

Glad to see at least some kind of extinguishers added, but more would be nice.

[Noveos_Republic 503]

@_qaz_

How effective were the CO2 cannisters? I'm pretty sure the G4M had them, but they were notorious for burning up

[Chomusuke1 1,217]

Quote

A-10 (all versions), Harrier (all versions), AV-8 (all versions), F-14A Early, P-61 (all versions), A-26 (all versions), Tu-4, B-29, B-17 (all versions), PB4Y (all versions), PBJ (all versions), B-24 ( all versions), B-26 (all versions), B-25 (all versions), MiG-23 (all versions), Su-22 (all versions), Su-17 (all versions), Su-7 (all versions), Q-5 (all versions), A-5C, J-7 (all versions), MiG-21 (all versions), MiG-19 (all versions), Yak-38 (all versions)

 

It is just amusing how one of the most widely known ground attack aircraft to use fire extinguishers (Hs 129) was conveniently omitted....I bet this was done deliberately since gaijin just loves nerfing that aircraft :

 

 

Also fire extinguishers were widely known to be used on the Do 335 as well:

 

Edited December 14, 2022 by Chomusuke1

[Teh0 294]

Great thanks to Ru_i for posting info about the fire extinguishing systems used in A6M.
 

 

[_qaz_ 675]

 

In the OP please add Kikka. In the Navy's plan requests made at the start (12/1944) and after construction had started (4/1945), protection of the fuel tanks with an automatic fire extinguisher was specified. This text was originally published in issue 1/1953 of Aireview.

Edited September 2, 2022 by _qaz_

[_qaz_ 675]

Did anyone submit a report about Reisen, Raiden, or Shiden engine extinguishers?

[Noveos_Republic 503]

21 hours ago, _qaz_ said:

Did anyone submit a report about Reisen, Raiden, or Shiden engine extinguishers?

nope

[CokeSpray 7,272]

Suggestion passed to the developers for consideration.