Spitfire PR XI and PRIV - armour plate behind seat?

[DOD]

Hi there,

I was led to believe that these two aircraft did not have any armour.  However, on looking at this review of the PR XI I see from the sprue photos what appears to be armour plating for behind the seat.

Can anyone confirm whether these aircraft did or did not have the seat armour?

Many thanks

David

 

 

[Julien]

I know some of the armour was removed from the PR.XI but from what im reading it does not breakdown what was removed ?

 

Maybe someone with more Spitfire knowledge than I have cna come up with a definitive answer. 

[Andy Fletcher]

Seat armour protection was retained on all marks.

[DOD]

5 hours ago, Andy Fletcher said:

Seat armour protection was retained on all marks.

Hi, thanks for this.  I have subsequently been in contact with the AA810 PR IV restoration project and they say there was no armour on the PR IV.

The PR XI I take it did retain the seat armour?

Cheers

[Andy Fletcher]

Hi DoD,

 

The info comes from AP1565M, P, Q & R, which covers the Spitfire PR.IV, PR.VII, PR.XI and PR.XIII

 

The last sentence of para 7 of the introduction states:

 

"Seat armour protection is provided on all marks."

 

I have no direct physical hands on knowledge of PR Spitfires but it was my understanding that most of the armour was deleted in PR types with the exception of the seat armour. Wasn't the pilot's headrest attached directly to the armour plate at the back of the seat? The headrests are clearly visible on many images of PR Spitfires, though that in and of itself is not proof of the armour at the rear of the seat being fitted.

 

Regards

[DOD]

Hi Andy,

I asked the question about the headrests on the PR IV and it was attached to frame 11 behind the seat with poppet rivets. No actual armour plate.

Cheers 

David

[spitfirepr1v]

Hi DoD

 

Rather late but have only just read this .

Andy is quite correct in that armour was fitted to all PRIVs as standard.

If AA810 was found with no seat armour I would suggest this had been removed for some reason or other ( weight saving given the distance and need to concserve for fuel consumption to Norway and back).

RAF Benson did a lot of its own modification for specific/special jobs via squadrons ground staff or via the Initial Preparation and Installation party, part of this unit's job was too modify aircraft both Spitfires and Mosquitos ( my uncle was an ex 1PRU and 542 Sqn pilot who later became the air test pilot for the IP&IP unit) .

I have a couple of photos which clearly show seat armour on Spitfire PR1Vs

 

The PR were a maverick bunch, left to their own devices regarding aircraft. I know this to be a fact as over a long course of time researching them, I met a number of pilots and navigators who confirmed this .

 

Richard

 

[fishplanebeer]

The early Spitfire 1's also had no armour fitted so the headrest was fixed directly to the frame behind the seat (frame 11).

 

When armour was introduced the seat armour fitted directly behind the seat (with a cut out on the port side to fit around the existing cockpit equipment) and the triangular head armour piece was placed slightly behind this and incorporated the head rest.

 

It's more than possible that in order to save weight some local adaptations were made to the factory fit armour as the expectation was that these aircraft would not be intercepted so no longer required armament or armour.

 

HTH.

 

Regards

Colin.

[FinnAndersen]

Please note that removal of the seat armour would upset the CG and that you had to compensate. It is not a trivial task to do.

 

/Finn

[DOD]

19 hours ago, spitfirepr1v said:

Hi DoD

 

Rather late but have only just read this .

Andy is quite correct in that armour was fitted to all PRIVs as standard.

If AA810 was found with no seat armour I would suggest this had been removed for some reason or other ( weight saving given the distance and need to concserve for fuel consumption to Norway and back).

RAF Benson did a lot of its own modification for specific/special jobs via squadrons ground staff or via the Initial Preparation and Installation party, part of this unit's job was too modify aircraft both Spitfires and Mosquitos ( my uncle was an ex 1PRU and 542 Sqn pilot who later became the air test pilot for the IP&IP unit) .

I have a couple of photos which clearly show seat armour on Spitfire PR1Vs

 

The PR were a maverick bunch, left to their own devices regarding aircraft. I know this to be a fact as over a long course of time researching them, I met a number of pilots and navigators who confirmed this .

 

Richard

 

Hi Richard

Many thanks for the comments. Would it be possible to see the photos showing the seat armour? I have not seen any good photos of PR IV cockpit areas.

I take it from your moniker and your reply that you are seriously into RAF PR subjects. It was the story of AA810 recovery that got me back into aircraft modelling and generated a general interest in the subject.

Thanks again, 

David

[fishplanebeer]

The early Spitfire had no seat and head rest armour so presumably it was possible to fit it, and conversely remove it, without greatly affecting the CG?

 

Regards

Colin.

[mhaselden]

Since the armour was aft of the CofG, its removal would have likely improved handling rather than made it worse.  

[Peter Roberts]

7 hours ago, mhaselden said:

Since the armour was aft of the CofG, its removal would have likely improved handling rather than made it worse.  

 

Wouldn’t it have been the opposite? I’m not big on this detail but my understanding, at least with the early Spitfire Marks, is that extra weight was incorporated in the tail to help with the CofG because there was so much weight forward of the CofG. Or have I got this wrong? Further, my understanding is that this improved with later Marks when some installations, such as fuel and oxygen, were installed in the rear fuselage. Or have I got that wrong too (?)

[gingerbob]

If the CG is farther aft than it is supposed to be (% or "inches back" on wing chord) the aircraft tends to become less stable.  There were problems on Mk.Vs as more equipment was added to the rear fuselage.  The ballast weight was to put the CG to the right range.

[mhaselden]

3 hours ago, Peter Roberts said:

 

Wouldn’t it have been the opposite? I’m not big on this detail but my understanding, at least with the early Spitfire Marks, is that extra weight was incorporated in the tail to help with the CofG because there was so much weight forward of the CofG. Or have I got this wrong? Further, my understanding is that this improved with later Marks when some installations, such as fuel and oxygen, were installed in the rear fuselage. Or have I got that wrong too (?)

 

It rather depends what mark you're talking about.  The fighter variants had guns roughly on the CofG while some of the early PR variants had cameras aft of the CofG.  

[Dave Swindell]

Adding or removing weight from any aircraft has to be done carefully, and can affect aircraft performance irrespective of whether it moves the GC forward or aft.

Each aircraft type will have acceptable limits forward and aft of a datum for the CG, and moving the CG outside these limits either forward or aft will adversely affect the handling, too much outside the limits will make the aircraft dangerous or impossible to fly. To keep the aircraft within CG limits ballast weights are often used. Interwar two seaters often had external ballast weights on the rear fuselage if flown without the rear gunner, and the Lysander had windows just forward of the tail so the pilot could check the appropriate ballast weights were in situ before taking off.

With respect to Spitfire armour plate being removed, this was heavy and not far behind the CG, so removing it could be compensated for by fitting a smaller weight in the tail giving a net weight reduction.

EG removing a 5kg weight 1m behind the datum and adding a 1kg weight 5m behind the datum would have no impact on the CG but would reduce the aircraft weight by 4kg 

CG would have been a constant battle during the Spitfire development - heavier engines further forward (initially with the 2 stage merlin and later with the griffon) would move the CG forward which would necessitate adding or moving weight further aft to compensate. 

Keeping consumables weight (CG) at or near the aircraft CG minimises their affect on trim as they are used. 

The spitfire rear fuselage fuel tank pushed the cg towards the rear limit when full, it was recommended to use this tank after takeoff to improve cg before engaging in combat.

[mhaselden]

I'm not saying that removing armour had no consequences, nor am I saying that it was done without due care and attention to weight and balance.  However, it was easily within the scope of squadron-level maintainers to do that work and ensure the appropriate ballast weight was applied, if necessary.  For example, when the RAF Buffalos were delivered to squadrons at Singapore, they had no armour behind the pilot.  When appropriately-designed and cut armour plates were provided, they were installed at the squadron level.  There are first-hand accounts by the aircraft maintainers of doing that installation...and the fun they had crawling around in the rear fuselage to install the plate.