WW2 Aircraft Ranked by Weight of Armour Plating

[Deleted member 68059]

The purpose of armor is to keep the aircraft in the air, not to protect the pilot. If I put the pilot in a box of battleship armor, but have completely unprotected fuel tanks, my design is not very good.

I see you have never looked at any diagrams of where the plating IS on an aircraft then.

You cannot fully plate fuel tanks as they cover such a large area the weight would be gigantic, which is why people use self sealing tanks.
The schematic below is typical for nearly all WW2 fighters, you may get some plating to cover the cannon shell magazines
or oil tanks too but that's it. The shell magazines being protected to stop them exploding and hurting the PILOT.

The P-38 also has armour around the INSIDE edge only of the exhaust turbocharger turbines, so that if the turbine
looses any blades they dont fly off and hit the PILOT.

 

[Shortround6]

The purpose of armor is to keep the aircraft in the air, not to protect the pilot. If I put the pilot in a box of battleship armor, but have completely unprotected fuel tanks, my design is not very good.

True but it seems like the chart is listing armor and not "protection"
A P-40 (no letter) with unprotected tanks had a 171lb fuel system.
The P-40C through K used a 420-437lb system.
On the P-40 B though E the armor and BP glass was listed under the Basic weight (not empty) but from the Fs and onward the armor and BP/glass was listed in the empty weight but totaled up with armament provisions (what ever those were?)The "armament provisions" catagory apparently didn't exist for the early versions.

 

[GTX]

It would be interesting to also see the Axis aircraft in this

 

[elbmc1969]

I see you have never looked at any diagrams of where the plating IS on an aircraft then.

You cannot fully plate fuel tanks as they cover such a large area the weight would be gigantic, which is why people use self sealing tanks.
The schematic below is typical for nearly all WW2 fighters, you may get some plating to cover the cannon shell magazines
or oil tanks too but that's it. The shell magazines being protected to stop them exploding and hurting the PILOT.

Oh, I've looked at plenty of them. Pilot armor is the main thing, not the only thing. I was responding to Shortround's statement that "US planes didn't put armor in front of their ammo. .50 cal ammo doesn't explode like 20mm HE does on occasion. It doesn't have any explosive." That may be true, but it is also irrelevant, since having the 20mm rounds explode may not kill the pilot, but it will prevent the aircraft from staying in the air.

In an earlier topic, we looked at fuel tank armoring. You don't need to armor all sides of a fuel tank to get important benefits. The German medium bombers had the front (back?) of their wing tanks armored because that was where they were most likely to be hit, and most vulnerable to incendiary ammunition. Hits from above were relatively rare because fighters tried to line up well into the rear quarter.

Anyhow, no need to be snide--I was basing my statement on looking at a lot of armor diagrams.

Thank you for producing these excellent graphs. They are very informative. I do think that the percentage version is important, even with the limitations that you described correctly. Could you post the .CSV file, so that folks can try adding other weights to see the effects? (Empty, 50% fuel, etc.)

(Oh, and some of the mid-engine designs offer the tantalizing possibility of armoring the engine. Armor behind it also protects the pilot, and all of this could make the aircraft much more survivable. On the other hand the insane Dewoitine D.580 / SNCAM M.580 / Sud-Est SE.580 armored the radiator!)

 

[Shortround6]

Diagram for a Seafire.

"That may be true, but it is also irrelevant, since having the 20mm rounds explode may not kill the pilot, but it will prevent the aircraft from staying in the air."

Having an Axis 20mm shell explode in your .50 cal storage is certainly not a good thing but it is not quite the significant emotional event that have some of your own 20mm ammo explode in the storage bin/drum would be.
The pilot has a bit more time to sort out what course of action he will take. Maybe just few seconds or may be a few minutes.

 

[Deleted member 68059]

Anyhow, no need to be snide

True, I apologise.

 

[elbmc1969]

Having an Axis 20mm shell explode in your .50 cal storage is certainly not a good thing but it is not quite the significant emotional event that have some of your own 20mm ammo explode in the storage bin/drum would be.
The pilot has a bit more time to sort out what course of action he will take. Maybe just few seconds or may be a few minutes.

No idea what your point is.

 

[GrauGeist]

That may be true, but it is also irrelevant, since having the 20mm rounds explode may not kill the pilot, but it will prevent the aircraft from staying in the air.

Plenty of aircraft or various types suffered 20mm strikes and remained airborne.

 

[pinehilljoe]

Due to much whinging on another platform an updated graph.
(NB. The results are artificially flattened because max gross takeoff weight obviously includes a LOT of bombs for the bombers. Whereas fighters need that "spare" power/weight to achieve high dynamic performance. So you still need to consider both metrics very carefully. In other words, a bomber fully laden can afford to "just" be able to lift off the ground with a very long run, and climb slowly, but a fighter cant afford to as it must take off fast and usually also climb very fast, so although a fighter COULD, carry more weight
and still take off, they dont, so the "% of Gross TO wt" will tend to make the fighters look more armoured and the bombers less so.)

View attachment 704527

I believe you, but could you site the source for the figures on the Il-2, its hard to believe a 1940 design propeller plane could get off the ground with 16% of its weight as armor/dead weight.

 

[Greg Boeser]

GG - He's referring to your own 20mm cooking off in the tray.

 

[SaparotRob]

I never knew the Spitfire, or any plane for that matter, had armored ammo boxes.

Edit (sometime later): I should have written armor protection or armored trays(?). Not the box o' bullets.

 

[Greyman]

The British armoured their 20-mm magazines if they were vulnerable to fire from the front.

Conclusions from Vulnerability of 20 m.m. H.E.I. Ammunition in a Spitfire Wing, to attack from direct ahead. (Orfordness Research Station, December 1941)

1. 20% of the rounds of 0.303 inch A.P. ammunition striking the ammunition box of a 20 m.m. installation in a Spitfire wing will cause detonations of the H.E.I. ammunition.
2. This probability is likely to apply to magazine feeds with only slight modification.
3. It is confirmed that the damage caused by a detonation is lethal.

 

[GrauGeist]

GG - He's referring to your own 20mm cooking off in the tray.

Ahh...gotcha, my bad

In regards to a source for the IL-2's armor, Bill Gunston's "Encyclopedia of Russian Aircraft: 1875-1995" is a good start.

 

[Shortround6]

No idea what your point is.

Significant emotional event if you are flying the plane when that happens.

It is not going to be a good day if enemy rounds get into the .50 cal storage but it won't be instantly catastrophic.
US didn't armor the ammo storage because the risk was nowhere near as great.
The US .50 also didn't destroy the enemy planes quite as quickly as 20mm fire (quick being the difference of low single digits in seconds).

 

[blueskies]

 

[blueskies]

Note the F8F used two air gapped plates behind the pilots head.

 

[MikeMeech]

Hi
Another mention of the book 'Knights of the Skies' by Michael C Fox, this has some WW2 drawings of armour plate on German aircraft dated Feb 1941, so based on aircraft shot down the previous year probably:

Of course armour plate was increased during the war, from the same source, armour on Ju-87 variants:

Mike

 

[OldGeezer]

Many surprises here. I am guessing the Thunderbolt has less armor because of the radial engine being less vulnerable?

Also a bit surprised how much armor is carried by the Boston, Mosquito and Ventura.

Can someone explain the difference in armor between the Mustang vs. older Allied fighters?

I wonder if some of these are using more efficient armor plate (high carbon / tempered vs. rolled etc.)

I know from numbers on medieval armor that medium carbon, tempered armor had the same bullet protection at 3mm thickness as untempered steel at 6mm or wrought iron (equivalent to modern 'mild steel') at 8mm, so the quality of the metal makes a big difference.

I believe they were experimenting with heat treatment of armor for aircraft but I don't know the details.

How do different variants of Bf 109 and Fw 190 compare to these?

I spent most of my 42-year aerospace career in the field of combat aircraft survivability, so I'd like to take a crack at "the difference in armor between the Mustang vs. older Allied fighters." Survivability has 2 factors, "susceptibility" and "vulnerability." Vulnerability is what happens after a hit has been scored, Susceptibility is about how to minimize the probability of being hit in the first place. The better (lower) an aircraft's susceptibility, the less vulnerability reduction needs to be incorporated in order to get to a given level of overall survivability. F-35 is the most recent example I personally know of (I've been retired for half a dozen years now) where low susceptibility (due to its stealth features) was successfully used as a justification for deleting some of the originally-incorporated vulnerability reduction features, at least from the STOVL variant. The details are in its Live Fire Test reports if anyone's interested. So back to WW2: The Mustang was faster and higher-flying than the P-39 and P-40 and others of an earlier generation, so that meant that weight could be saved by trimming the hardening features. I suspect that's driving at least some of the earlier/later armor weight trends in the chart.

 

[Wild_Bill_Kelso]

Very interesting, and the perspective of people who worked in the industry is always appreciated.

I think we have to be careful comparing contemporary and WW2 aircraft design, because for example, a modern fighter-bomber (or "strike fighter" is I guess what they would call them today) can drop a precision munition from 10,000 feet and still hit a target. In WW2, when fighters were used as CAS or for strikes, they had to get very low. Well within range of light AAA and even small arms. This was potentially very hazardous of course, even if you had an extra 20-30 mph of speed at that altitude.

Needless to say, flying at 30,000 ft there is relatively little threat from flak, and since Mustangs flying escort missions for strategic bombers, their most important role, mostly faced enemy fighters, they didn't get hit with return fire as often (except from some of the 'heavy fighters' they sometimes engaged with). Mustangs could also escape from most enemy fighters due to their very high speed at altitude, always a very important trait for fighters, which also enhanced survival rates.

In Theaters where they were used in a more tactical role, P-51 were noted by some Allied pilots for having vulnerable cooling systems, since this extended to the wings. By comparison the Typhoon, Tempest or the P-40 had most of it's cooling plumbing in the front of the aircraft which was a little bit harder to hit, especially by ground fire. Aircraft like the Thunderbolt, the Wildcat or the Hellcat, or the earlier Fw 190s or the La 5, had air cooled engines which didn't require radiators, though the P-47 had the turbo system which could be vulnerable.


As for whether elminating some of the hardening of the F-35, whatever that actually means in detail, I guess we will find out. Some of the design decisions for that aircraft seem to be a bit questionable, but we won't know until they are in action. In the past, the US has made decisions like removing guns from aircraft because they though missiles would always work, which didn't turn out to be true... hopefully the stealth tech on the F-35 will prove to be extremely effective if we ever have to use them in a real war. Hopefully later rather than sooner.

 

[Wild_Bill_Kelso]

as far as weight of armor, I still kind of wonder if it may have had something to do with improving metallurgy