BOB aircraft armour
 

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

Re: BOB aircraft armour
 

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

Re: BOB aircraft armour
 

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

Re: BOB aircraft armour
 

[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.

Re: BOB aircraft armour
 

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

Re: BOB aircraft armour
 

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.

Re: BOB aircraft armour
 

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

Re: BOB aircraft armour
 

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.

Re: BOB aircraft armour
 

[quote=Graham Boak;62084]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.

Re: BOB aircraft armour
 

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

Chris

Re: BOB aircraft armour
 

Mod #273 - fit self sealing to lower tank, 27-7-40

Re: BOB aircraft armour
 

Then all of this raises a number of questions. If the modification of the inclusion of back armour was accepted in late 1939 , then why does it appear that it took so many months for this to apparently reach the factories and subsequently operational squadrons, I wonder? There are a number of anecdotal accounts in pilot memoirs which bemoan the lack of armour plating behind the head in early to mid 1940, so was it merely a case of it taking a number of months to introduce the addition and for it to be seen in numbers in operational squadrons or was this dragged out for some particular reason or fault?

Don't have the answers but interested to hear others views and opinions on this.

Re: BOB aircraft armour
 

The reference I know is from Fighter Pilot. 1 and 73 Sqs were the first deployed and took their prewar aircraft with them, so clearly would not have any such mod. I suspect it is partly the time to introduce the mod, and partly the time for such aircraft to get out to the frontline units in France - which for much of this time had very little attrition and hence no need for replacements. Do the other references come from squadrons early to deploy?

One reasonable point is that armour plate takes rather more time than simple alloys to produce and indeed to work to the desired shape and fittings. There may well have been priority problems: resulting in aircraft coming off the line fitted "for but not with".

It may have been a different matter for 607 (my own particular interest) which was equipped in the field with new P series Hurricanes in April 1940.

I quite agree that September to April does seem long: it would be interesting to find more about this. However, histories tend to be a bit vague about modifications in between the milestones of Mark numbers: which is why the rapid conversion to constant speed props in June 1940 stands out as so significant.

Re: BOB aircraft armour
 

Trust No1!!

"In Omnibus Princeps" - First in all Things or, as we saw it, Quicker by Bus!!

http://img.photobucket.com/albums/v1...4/RAF2/no1.jpg

Re: BOB aircraft armour
 

From Ring`s old site.

As of May 10, 1940

no Spitfire Squadrons,
5 Hurricane Squadrons

have armor fitted. 2 Hurricane Squadrons will have armor fitted shortly.

http://i38.photobucket.com/albums/e1.../hsarmour1.jpg

Description of Spitfire I armor from German tech report.

- 4,3mm armor plate in front of fuel tank
- 3,5mm dural plate above top fuel tank (deflector plate)
- 38mm armored glass front, and 'davor Spaltabdeckplatte (4,5mm)'
- 6,2mm armored headrest
- 4,5mm plate behind pilots back

The whole thing weights 51 kg.

Thing that makes me wonder is the 4,5mm back plate. This doesn`t seem to be sufficient against any sort of AP munition.
As far as I know, the lower fuel tank on the Spitfire (or the upper?) was never self sealing for technical reasons, namely, the lack of space.


Armor on Bf 109s and especially, the 110 is a bit of a mystery. It is clear that early Emils did not have armor either. It is also clear that some sort of armor was fitted by December 1939, as the preliminary Emil E-1/E-3 manual issued on 16 December 1939 (kinda funny, considering the Emil was in production since late `38..) notes that the loading plans are not valid for aircraft with armor plates.. I presume the manual still had some early Ladeplan which were now obsolate, but not yet replaced. Pictures of BoB-period aircraft clearly show the armored headrest, too, and there are some pictures of armored glass fitted, the latter, however, appears to be rare; I suppose it was useful when fighting bombers, and RAF bombers seen in the daylight after France were rare, therefore, the armored glass was probably not preferred.

Foreign evaluation repororts are not very helpful, since both the British and the French had tested the same aircraft, Wnr 1304, and that aircraft was captured back in 1939, appearantly before armor was retrofitted, as it was noted by the French that it did not carry armor.

Re: BOB aircraft armour
 

Who was firing AP munitions when the armour was designed in 1939? The standard 109 armament of the time was 4x0.79mm mgs. 4.5mm would be enough to stop a direct hit by an mg bullet, and at least shrapnel from cannon. A direct hit by a 20mm might penetrate, but the early MG FF wasn't the most effective of aircraft cannon. I bow to superior knowledge of its penetrating abilities.

Like all things in aircraft design, it is a trade-off. Tanks don't fly.

Re: BOB aircraft armour
 

Thanks.

Re: BOB aircraft armour
 

Yesterday I received the following book from Midland Counties.

Knights of the Skies: Armour protection for British fighting aeroplanes.
Michael C. Fox, Air Research Publications 2006, ISBN 1-871187-50-8

I haven't finished it, but it certainly covers the time period concerned in this thread. It begins with the first British AA trials in 1910, and continues until the acceptance of the need for armour on British ground attack aircraft, immediately prior to the Hurricane Mk.IV and regrettably not covering the armour fitted to late Typhoons.

It looks to be very good indeed.