# bulletproof glass?



## João Yazalde (May 8, 2022)

In many games I have seen that a plane can have bulletproof glass. I thought that this was not real in the war and that it was just a modern invention. But I read that the A6M0 "didn't have bulletproof glass", so it did exist. After seeing the size of the bullet casings and the holes in the fuselages I wonder if that glass was strong enough to withstand bullets. Was this glass effective? Why did many pilots die riddled with bullets if that protector existed?


----------



## cvairwerks (May 8, 2022)

Bullet resistant glass is quite heavy....typically about 4" thick, with a corresponding weight. It's also complicated to mold it to anything but a flat plane and maintain optical clarity for the pilot's needs.

Reactions: Like Like:
1 | Like List reactions


----------



## fubar57 (May 8, 2022)

Bullet proof glass on a Curtiss H-81A

Reactions: Like Like:
2 | Like List reactions


----------



## MiTasol (May 8, 2022)

WW2 bullet proof glass tended to be about 50mm thick and as stated was heavy

My P-40N glass weighs 14.9kg/32.8lb and is 40mm/1-9/16" thick. Earlier P-40 glass was thicker and heavier and a different lamination combination.

Reactions: Like Like:
2 | Informative Informative:
1 | Like List reactions


----------



## João Yazalde (May 8, 2022)

I see, it could not be used frequently because of its thickness and weight. Only one rectangular piece could be placed on the front.


----------



## Wurger (May 8, 2022)

Actually not exactly ...


----------



## MiTasol (May 8, 2022)

many are curved on top and though most have straight parallel sides. Some are curved on the bottom to fit the fuselage contour. Some, like the P-38 side panels on the windshield are curved laminated glass tho that is only about 3/8 10mm thick


----------



## Wurger (May 8, 2022)

Here is the windscreen of the Fw 190A with the integrated 50mm bulletproof glass. Plese note how thick and heavy was the frame for the glass.






What is more the additional glass armour of the slided back cockpit hood could be added ....

Reactions: Like Like:
1 | Informative Informative:
1 | Like List reactions


----------



## Shortround6 (May 8, 2022)

João Yazalde said:


> Why did many pilots die riddled with bullets if that protector existed


Because of the weight both BP glass and steel armor (seat backs, etc) could only be used in small areas and on limited arcs. 
It was based on percentages. 
If a fighter is attacking at bomber the bomber's guns are going to be firing at the nose of the fighter for much greater period of time than when the fighter flashes by in a fraction of a second. Since the engine blocks most the bullets coming in the front only the pilots head/shoulders are exposed to the bombers gun fire. 
Assuming the fighter pilot is not wounded or wounded badly he can bail out of the crippled fighter (damaged engine). 
the other area for in coming fire is from the tail at about 6 oclock and for a certain number of degrees off to the side or vertical usually less than 10 degrees off the center line? 

After that the pilots were depending on luck for the bullets coming in from the sides/ bottom and top.

Reactions: Agree Agree:
2 | Like List reactions


----------



## João Yazalde (May 8, 2022)

Ok, I got it. Now that you mention the engine, How could the pilot fire his machine gun without the bullets damaging his propeller?


----------



## Wurger (May 8, 2022)

Because of a device called a gun synchronizer or interrupter gear built by A.Fokker and using during the WW1 for his Eindecker fighters.









Wikiwand - Synchronization gear


A synchronization gear was a device enabling a single-engine tractor configuration aircraft to fire its forward-firing armament through the arc of its spinning propeller without bullets striking the blades. This allowed the aircraft, rather than the gun, to be aimed at the target. There were...




www.wikiwand.com

Reactions: Like Like:
2 | Like List reactions


----------



## Greg Boeser (May 8, 2022)

Aircraft with fuselage mounted machine guns, which would fire through the propeller arc, were equipped with synchronizing gear to ensure the guns only fired so that the bullets passed between the rotating blades.

Reactions: Like Like:
2 | Like List reactions


----------



## fubar57 (May 8, 2022)

​

Reactions: Like Like:
2 | Agree Agree:
1 | Winner Winner:
1 | Informative Informative:
1 | Like List reactions


----------



## João Yazalde (May 8, 2022)

Thanks


----------



## swampyankee (May 8, 2022)

João Yazalde said:


> In many games I have seen that a plane can have bulletproof glass. I thought that this was not real in the war and that it was just a modern invention. But I read that the A6M0 "didn't have bulletproof glass", so it did exist. After seeing the size of the bullet casings and the holes in the fuselages I wonder if that glass was strong enough to withstand bullets. Was this glass effective? *Why did many pilots die riddled with bullets if that protector existed?*



Did many pilots actually die "riddled with bullets?" 

The materials available for armor during WW2 are* _heavy_. Armoring an aircraft to the point where it can't be "riddled by bullets" is impractical if the aircraft, especially a fighter aircraft, is going to have a useful level of performance, so one places the armor so as to maximize its effectiveness in preventing the most likely critical damage. Then, that annoying enemy goes and uses AP ammunition or switches to larger caliber weapons.

Reactions: Like Like:
1 | Like List reactions


----------



## Jabberwocky (May 8, 2022)

João Yazalde said:


> In many games I have seen that a plane can have bulletproof glass. I thought that this was not real in the war and that it was just a modern invention. But I read that the A6M0 "didn't have bulletproof glass", so it did exist.



Laminated and multi layer glass (you could call it bullet resistant or semi-armoured) was probably first used on a fighter aircraft around 2 years before the end of WW1. There were a number of aircraft - both German and British - that featured thick (~1.5 to 2 inch) forward windshields in service in 1916.

This wasn't proper 'bulletproof' glass - ie tempered and toughened. It was more akin to present day safety glass. However, there are accounts of it deflecting or stopping fire from opposing aircraft (and also failing to). 'TriPlex' was specifically marketed during WW1 as being 'bullet proof' and 'shatter proof' for use in aircraft windshields, instrument panels, observation windows and pilot goggles.



João Yazalde said:


> After seeing the size of the bullet casings and the holes in the fuselages I wonder if that glass was strong enough to withstand bullets. Was this glass effective?



Depends on what is doing the hitting, and the range and angle. 

A plain old .303, .30-06, 7.62x54R or 7.92x57 ball round only has 2500 to 3000 ft pounds of energy. Striking from the rear at medium to long range (say, more than 250 yards), or at an oblique angle, these sorts of rounds might not penetrate. However, the same round hitting straight on, or from a head on attack might have enough energy to penetrate. 

Something like a US .50 BMG or Soviet 12.7X108 round has a LOT more energy (about 18,000 to 20,000 ft pounds). That bigger, heavier round is probably going to punch through something that the smaller .30 cal class weapons cannot.

Bigger cannon (20mm and above) and above are a bit more of a mixed bag. They've got more energy again, and some of their ammunition was armour piercing. However, a lot of cannon ammunition wasn't designed to penetrate armour - they shells typically had bluntish noses to accommodate their fuses, and this isn't something really conducive to pushing through something like armoured glass. However, they did carry varying high explosive payloads, so there's the impact of a 10 grams or more of HE going off to consider, in addition to the kinetic energy of the round. 

Also, you have to consider what could happen with multiple impacts. A Hurricane I or Spitfire I is putting ~9000 to 9400 rounds per minute down range - or about 150-160 rounds per second. A piece of armoured glass on a 109E is a small target, but if 150+ rounds a second are flying at you, the first might damage the glass and another lucky one or two hits actually penetrate it.

Reactions: Like Like:
1 | Like List reactions


----------



## João Yazalde (May 9, 2022)

Interesting


----------

