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mortoma1958
08-27-2006, 10:51 PM
Doing an offline campaign flying the J2M3 in the Japan map against Stangs and B-29. I always survive but can't get my crippled plane back to base, instead I have to bail or crash land. After pouncing on the bombers I always get at least one fuel leak and the engine runs out of fuel fast in this plane if you get a leak. I thought that the J2M3 had self sealing tanks?? Well, in any case I will keep trying to get one home sometime. Very challenging so far. Very nice opponent for the Ponies below 5,000 meters. Much above that bad news. If you try this campaign, attack B-29s with care. They make B-17s seem under-armed.

mortoma1958
08-27-2006, 10:51 PM
Doing an offline campaign flying the J2M3 in the Japan map against Stangs and B-29. I always survive but can't get my crippled plane back to base, instead I have to bail or crash land. After pouncing on the bombers I always get at least one fuel leak and the engine runs out of fuel fast in this plane if you get a leak. I thought that the J2M3 had self sealing tanks?? Well, in any case I will keep trying to get one home sometime. Very challenging so far. Very nice opponent for the Ponies below 5,000 meters. Much above that bad news. If you try this campaign, attack B-29s with care. They make B-17s seem under-armed.

LEBillfish
08-27-2006, 11:39 PM
Though I can speak to no other nations planes, for the Japanese I can only add this about "Self Sealing" fuel tanks........

Initially on IJAFC aircraft (the J2M Navy) what some might call "self sealing" was in reality simply a heavy silk felt over the tank then encased in a very thin (3mm) or perhaps thinner natural rubber. The intention being to keap fuel from streaming out like we so often see in films of A6M's hit.....That streaming fuel and vapors more so the reason often for those sudden intense fireballs.......It actually more accurately referred to as "Leak Absorbing" which was often effective "enough" against the standard rounds of the day (7-8mm) and could very well have fragmented the bullet up enough or deformed & absorbed the energy enough it at least to a point to "aid" as bullet "proofing".

Ki-43, Rubber over Silk Felt Fuel Cells from "Aero Detail #29, Nakajima Ki-43 Oscar"....

http://img.photobucket.com/albums/v707/Kaytoo/78th/Untitled-1.jpg

As the navy continued on with their "don't get shot and you'll not have a problem" policy, weight contrary to their planes design, the army as shown on the Ki-61 for example continued to improve on their protection.

Silk felt and thin rubber soon was replaced by evr thicker pieces of rubber their thickness determined by the probability of a hit progressively. from 6 & 9mm to eventually a full 12mm all around. This can even be seen as such a worthwhile addition that instead of sacrificing the rubber armor, fuel volume was reduced instead as a worthwhile trade off. The new term applied was "Bullet Proofing". Now that term can be misleading in that it might actually worked out to many things.

No doubt, 1/2" of rubber could not stop a .50 caliber round, yet what of smaller rounds (7-8mm), though no doubt might have destroyed the rubber, it "may" have been possible to have reduced the energy enough to stop penetration of the sheet metal can itself. In kind it may have been somewhat of a self sealing feature in that rubber would stretch, then close back up at least slowing any leak. Lastly, it would also help reduce or prevent the possibility of "Hydroshock blowout"....and again if any rupture occured by the sheet metal, may have helped contain it. How effective it was I can't say not having any data.

However, wherein this would be fine for smaller rounds as stated I believe most U.S. rounds were .50 caliber though there may have been .30 caliber utilized on certain bomber positions. Never the less it still might have aided in reducing that "comet" result.

The problem you're seeing is one that is wrong for virtually all planes here I'd "assume". That being if a tank is hit, run off it till near dry and let the balance run out selecting a different tank. Japanese planes for the most part (assuming navy were the same as army), had a tank selector switch for this very reason, otherwise why not just have numerous cells all connected and draining equally?..........IOW, if out of 4 cells 1 was hit, you would at worst only lose that portion of fuel....Even the gauge was designed to allow you to be able to check tanks having a selector switch.

So in reality when hit having say 4 tanks, a better hit result would be losing just 1/4 of your fuel not all of it...Yet that's not the case as here it is though all tanks are connected and if one leaks they all drain.

Lastly, nothing, nothing in this world will stop a tank from losing that fuel if it has a hole the size of your fist in it. They may have methods to keep it from going everywhere, yet for all intensive purposes that fuel is lost.

You have three choices due to the fuel cell switching shortcoming........1. The second a tank is hit break off and rtb. 2. Know your plane, when hit, fight till your fuel drops to a point you know you must run then do it. 3. Stay and fight, yet be prepared to have to glide to a landing most likely not at the drome.

Lastly, take a full tank of fuel.......That very often where most run out after a hit. It's great to go light to be able to manuever better, yet a plane lost is a plane lost so change how you fight to fly heavy.

*******IJAFC Fuel tank bullet proofing dimension data information from "Jim Long's Airtell Publications & Research Services Report #99-3" taken from captured Japanese documentation of numerous IJAFC aircraft dated March 22, 1944.***********

woofiedog
08-27-2006, 11:50 PM
LEBillfish... Very interesting info on the Japanese Self Sealing Fuel Tank.

LEBillfish
08-28-2006, 12:04 AM
Fuel tank pic added.....

KIMURA
08-28-2006, 01:04 AM
The main reason adding rubber around the tank was the chemical reaction of rubber if in contact with gasoline. If a tank gets hit fuel poors out and get in contact with the surrounding rubber. As a result the rubber swells up and closes the arose hole. The self sealing tanks on western WWII design were able to seal leaks of up to 13mm of diameter.

mandrill7
08-28-2006, 05:51 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by mortoma1958:
If you try this campaign, attack B-29s with care. They make B-17s seem under-armed. </div></BLOCKQUOTE>

The plus side is that the B-29's are so massive, you can open up from well outside normal range and still score hits. With a heavily cannon-armed plane such as Jack, the hits should be sufficiently destructive to damage or destroy the plane if inflicted in the engine area.

p1ngu666
08-28-2006, 06:36 AM
the multi fuel tank thing is a really big issue tbh, any reduncy u have in your aircraft is actully more of a liability http://forums.ubi.com/images/smilies/16x16_smiley-sad.gif

Ernst_Rohr
08-28-2006, 08:15 AM
Its also a big issue vis a vis the huge ratio of fuel that Japanese AC all had. Japanese AC had huge fuel reserves due to the distances that they often had to travel.

Billfish is absolutely correct in stating that this is an issue, the "one big tank" syndrome in IL2 is definatly an issue, and a big one, since you will bleed out fuel quickly in any Japanese plane.