Glass Jaws

[comiso90]

And the fuel tanks were only lined with leather, one being placed ahead of the cockpit, the other being directly behind.

It doesnt seem that leather and fuel would mix well. It's only a matter of time until particles of leather would wear off and foul the fuel and lines..

was this done often?

.

 

[Butters]

The Hs-129 was very heavily armored, yet still extremely susceptible to even rifle-caliber ground fire due to the fragility of its engines. Unlike many air-cooled radials, the Gnomes were easily knocked out.

Add in the extremely poor single-engine flying characteristics of the Hs-129, esp the extremely over-weight later models, and it's no wonder that they had such a dismal service record. The sortie/loss ratio was horrendous.

JL

 

[drgondog]

As fearsome as the Me262 was, it had a number of potentially fatal flaws.

Aside from the vulnerablity during takeoff/landing, it's engines were tempermental and prone to catastrophic failure at the drop of a hat.

And the fuel tanks were only lined with leather, one being placed ahead of the cockpit, the other being directly behind.

Dave - I would have a different POV on the 262. The root of its issues was the state of metallurgy in the engines which to me are a sign of its early time position in breakthrough jet technology rather than an inherent design flaw.

It achieved remarkable capability despite many advanced concepts in airframe design and pilots were killed more because of materials failures to meet specs than an inherent design flaw - that the Luftwaffe would proceed knowing these issues is a decision that had to be made despite the known risks.

True that even when the engines were performing to specs the 262 was vulnerable due to the relatively low performance of the engines during spool up but that issue existed for years in many other jet aircraft during the engine evolutionary period of maturity - long after the 262 was long gone.

The aft fuel tank was a known design potential issue for aft cg problems - but another compromise that had to be made to give it enough range to be useable.

I didn't know about the leather lining. Because of rubber/sealant shortages?

 

[Micdrow]

I guess when it comes to this subject I would have the say the G4m Betty bomber, no armor and no self sealing fuel tanks.

 

[Colin1]

I didn't know about the leather lining. Because of rubber/sealant shortages?

I didn't either
but I didn't understand the earlier comment that 'particles of leather would wear off and foul the fuel and lines' - how would that happen?

 

[comiso90]

I didn't either
but I didn't understand the earlier comment that 'particles of leather would wear off and foul the fuel and lines' - how would that happen?

The comment was that the fuel tanks were "lined with leather" which means inside the tank, .. as opposed to "covered with leather " which would be outside...

I must be missing something cause it seems any organic material exposed to gasoline for an extended period of time would slowly dissolve. Maybe I'm about to learn something new!

 

[Colin1]

Maybe I'm about to learn something new!

I doubt it
not from me anyway but I'm a bit surprised to learn that they came up with an aircraft 10 years ahead of its time and then lined the inside of the fuel tanks with an organic material

I need to look this up, it sounds too silly to be true

 

[TheMustangRider]

I have read somewhere in the forum that a fully loaded FW-190 was a threat to its pilot since the explosive 20 mm cannon ammunition it carried in its wings could be ignited by a burst of incendiary bullets from an enemy fighter and make the entire wing section explode. What do you gents think about this, was this danger, if real, a constant risk for the pilot?

 

[GrauGeist]

I cannot remember all the details, such as thickness or how the leather was coated or faced, but it was used instead of rubber which was almost impossible to get in the later years of production.

I'm sure that when the 262 was under development, despite of it's design advances, was to have raw materials for it's components much like any of the other luftwaffe aircraft. As we know, the furtunes of war turned against Germany hard, forcing them to make compromises and trade-offs, and the leather liners in the fuel tanks was one of these instances.

I'm not sure how many other aircraft were given the leather liners during the later stages of the war, but I was told by a friend that the local citizens would seek out abandoned aircraft, and strip the leather from the tanks. I never asked what for, but I'd assume shoes?

And I agree Bill, perhaps the word "flaws" wasn't right in this case...I shoulda said weaknesses...

As for the leather breaking down and contaminating the fuel supply, I'm not sure how that was approached. The leather was (I'm assuming here) faced inwards? Or just kept in service for a certain amount of time before the fuels broke the leather down. Although I have seen leather used as gasket materials on older vehicles, so I'm not sure how long the liner would have held up with constant use.

 

[Flyboy2]

I heard that the Spitfire always suffered from a somewhat exposed glycol system that could be easily taken out in one hit... Is this true?

Also on the Spitfire, the fact that early Spitfire versions couldn't "bunt" a dive was a bit of a disadvantage

 

[Sweb]

Leather lined fuel tank. I would imagine it was used between a double-walled tank, similar to other tanks where a raw viscous rubber (unvulcanized) filled a void between the inner and outer tank linings, serving a similar function. Once punctured leather bounces back and with the sudden exposure to fuel it swells in the area of the puncture thereby closing off the leak. Early oleo strut and other system component seals (AN-Army Navy type) were leather. I worked in an aircraft hydraulic repair shop where leather 0-ring type seals were used. They had to be soaked with water in order to swell up enough to permit their installation, then dried once positioned in order to shrink back to their manufactured size to allow close-tolerance assembly to other parts like inner and outer shock strut oleos. Once assembled and serviced with the appropriate hydraulic fluid (usually MIL-H-5606) the seals would again swell and provide the sealing between subassemblies.

So, I'm guessing the leather used must have been dried and sandwiched between an inner and outer tank wall on the 262. Just a guess. There'd never be any direct fuel/leather exposure until a bullet penetrated.

Edit: IIRC, Corsairs had non self-sealing fuel tanks in the outer wing panels. I think they were about 37 gallons each. What they did have was a plumbing system that linked them to a nitrogen bottle in the cockpit. When engaging in combat the pilot pulled a handle on the bottle which flooded the tanks with nitrogen. As a side-note to this later models were equipped with a second nitrogen bottle situated next to the original bottle. It was used as an emergency high pressure source to extend the landing gear in the event the hydraulics were shot out or failed. In a moment's confusion several pilots pulled the wrong handle when engaging in combat and the gear extended. Once the gear was extended with the bottle it could not be retracted again and many of the pilots were shot down due to it. The gear bottle was subsequently relocated. (Source: Whistling Death by Boone Guyton - Corsair test pilot)

 

[Magister]

The Corsair appears to have been much more vulnerable than the Hellcat and the source of this vulnerability looks like it may have been the oil cooling system which was different on the Corsair than the Hellcat and Thunderbolt which also utilized the R-2800.

See Post #44 and the referenced discussion:

http://www.ww2aircraft.net/forum/aviation/thunderbolt-vs-mustang-17402-3.html

 

[MikeGazdik]

The compressibility issue so severely affecting the P-38 Lightning. It limited the aircraft so much. Oh so much!

And the other would be the darn low altitude superchargers on the Allisons for the P-40 / P-39!