BOB aircraft armour

[Adam]

Does anyone have figures/fact on armour plating (seat backs) for BoB Spits and Hurricanes?

I can't find the reference, but in something I've read recently it noted it
was rather limited - at least during the initial-mid stages of the Battle of Britain.

Any halp would be appreciated

[Smithy]

Hi Adam,

Back armour was initially not included on the Spitfire I and Hurricane I as the powers that were at the Air Ministry thought that its inclusion would adversely affect the balance of the aircraft.

It appears that in early 1940 1 Squadron in France were the first to fit back armour by installing this from a crashed Fairy Battle. A pilot from the squadron was later dispatched to Farnborough and performed an aerobatic display to demonstrate that aircraft balance had not been affected by the addition of back armour. After this back armour fitting became standard (unfortunately I do not have a firm date for this)

Also, which might interest you, back armour was 6mm thick.

Hope that helps,

Tim

[Kutscha]

Spitfire
Mod #140: fit rear armour, 19-10-39
Mod #189: introduce plastic pilot seat, 14-2-40

[Graham Boak]

[quote=Smithy;62073]Back armour was initially not included on the Spitfire I and Hurricane I as the powers that were at the Air Ministry thought that its inclusion would adversely affect the balance of the aircraft.

I've seem that written, but it is a very odd statement. Calculation of the movement of an aircraft's cg caused by the fitting of a new piece of kit, or any specific weapon or modification, is one of the simplest and most common calculations in aviation. The range of permissible cg positions is determined early in the flight test programme: so checking that fitting the armour was within the acceptable range must have been a doddle.

Had the cg moved outside the the acceptable range, then it is a matter of adding/removing ballast to compensate.

[Boomerang]

As a comparison, a schematic of a Bf 109 in Len Deighton's Battle of Britain shows an 8 mm armour plate fitted to that aircraft.

With reference to fitting armour to the RAF fighters, this book refers to: '...the sheet of armour plate now fitted behind the rear seat of all RAF fighters, after a squadron in France early in the war had tried it against official advice that it would 'spoil the balance of the aircraft'.'

Cheers

Don W

[Smithy]

Originally Posted by Graham Boak

I've seem that written, but it is a very odd statement.

I think we can all attest to the strangeness of Air Ministry and top level RAF thinking at some time or other! Fact of the matter was that both aircraft were not designed to carry back armour, and an unauthorised field modification of expensive government property was frowned upon.

Kutscha, that date seems incredibly early. All the references that I am looking at seem to infer that the relevant factories were not beginning to roll Spits and Hurris out with back armour until approximately May 1940.

[Kutscha]

Smithy, dates are from Spitfire: The History.

I take this to say that the OK was given to fit rear armour, not that it was necessarily* fitted from that date.

* added

[Graham Boak]

If it had reached the stage of a modification number being raised, then it was being considered before the outbreak of the war. Hence any local modifications of earlier aircraft in France were independent of Ministry decisions, and even later. This is perhaps another example where the Ministry was not as daft as sometimes argued.

[Nick Beale]

[quote=Graham Boak;62084]

Originally Posted by Smithy

Back armour was initially not included on the Spitfire I and Hurricane I as the powers that were at the Air Ministry thought that its inclusion would adversely affect the balance of the aircraft.

I've seem that written, but it is a very odd statement.

It's in Paul Richey's wartime memoir "Fighter Pilot" and shows how things looked from the perspective of No. 1 Squadron but it's not the same as finding the official paper trail. More than one person might have had the same idea or improvised some back armour, after all.

[CJE]

One thing leading to another, when did the self-sealing tanks appear on the Spit assembly lines as standard equipment?

Chris