# The Story of the Photographic Reconnaissance Spitfire



## mfg (May 14, 2006)

The story of the Spitfire as a photographic reconnaissance aeroplane starts at the end of 1939, by which time operational experience with Blenheims and Lysanders used on photographic missions had shown that an aeroplane capable of flying much faster and higher was needed. 

A special flight, christened the " Heston Special Flight," was formed, and was equipped with two Spitfires specially converted at RAE. Farnborough. With one F.24 camera mounted vertically in each wing these Spitfires did not prove satisfactory. The first, unsuccessful, sortie was made from a French base against Aachen on November 18, 1939; after a few more sorties the Flight returned to Heston on January 11, 1940. 

Re-named No. 2 Camouflage Unit, the Flight studied its mistakes and the shortcomings of the Spitfire as then converted, and there was evolved the first of a series of Photographic Reconnaissance Spitfires, forerunners of the Spitfire P.R.MkXI, probably the most successful photographic aeroplane in the world. The original R.A.E. modification was designated the Spitfire A; the next model, a service conversion made at Heston was the Spitfire B. One of the disadvantages discovered with the Spitfire A was the lack of range, so a 29-gallon fuel tank was introduced into the rear fuselage, behind the pilot, on the Spitfire B. One vertical camera was carried in a fairing beneath each wing; only a few Spitfire Bs were produced. At his point, the Heston Aircraft Co., Ltd., was asked to under-take the development work on the Spitfire, and to that company must go the credit for the ground work which eventually enabled the RAF, to obtain complete photographic coverage of enemy territory.

The first Heston Aircraft conversion was the Spitfire C, which for the first time used a vertical camera in the fuselage. The wing blisters were retained, but carried two cameras under the port wing, and additional fuel under the starboard wing. Extra oxygen was carried for maximum high altitude flying, and the 29-gallon rear fuselage tank was also retained. Next in line came the first variant used in appreciable numbers. 

The Spitfire D, as it was designated, incorporated several important modifications; a fuel tank of 66 gallons capacity was fitted in the leading edge of each wing, which gave a total fuel capacity of 218 gallons, there being no rear fuselage tank. No cameras were carried in the wings, but two F 8 (20-in.), F.24 (20-in.) or F.24 (14-in.) were mounted in tandem in the fuselage; these were "split,' i.e., both were slightly off vertical so that two overlapping photographs were taken simultaneously. 

Other features were hot air camera heaters, glycol cockpit heater and extra oxygen. The additional petrol necessitated more oil being carried, and this was provided in a 14-gallon tank in a small teardrop fairing beneath the port wing. Records of the Spitfire E are incomplete. It was a modification jointly evolved by R.A.E. and Photographic Development Unit (which the Camouflage Unit had now become) at Benson, and apparently mounted a camera in each wing, and one for oblique shots in the fuselage side behind the pilot. Almost concurrently with the Spitfire D, Heston Aircraft produced the Spitfire F, which allowed for the installation of one vertical F.8 (20-in.) camera, or two F.8 (20-in.) vertical split cameras, or two F.24 (20-in.) vertical and one F.24 (14-in.) oblique cameras. Oxygen economizers were fitted for the first time, and additional oxygen bottles were carried, one in each wing and one behind the rear fuselage tank. 

"Teardrops" were introduced on each side of the cockpit hood, to improve downward and rear ward vision, but the windscreen was not bullet-proof. Additional fuel was carried in a 29-gallon rear fuselage tank and in blister tanks under each wing; the capacity of the nose oil tank was increased and this resulted in a deepening of the cowl line, an important recognition feature of the late P.R.MkXI.

The final alphabetical variant to emerge was the Spitfire G, which was the first armed photographic reconnaissance Spitfire, having standard "A" wing armament of eight 0.50-in. machine-guns. Two independently operated vertical cameras, an F.24 (5-in.) forward and F.24 (14-in.) aft, were mounted in the fuselage, and an F.24 (8-in.). (14-in.) or (20-in.) could be mounted to port or starboard behind the pilot for oblique shots. An F.24 could be mounted for rearward and downward shots in the port cockpit door. All cameras were electrically heated, one extra oxygen bottle, and oxygen economizers were carried, the windscreen was bullet-proof and the cockpit had "teardrops," and a reflector sight was fitted. Armor plate was carried behind the pilot, and a rear fuselage tank, but no additional oil, was carried. While development of this series of Spitfires was in its late stages, the decision was made to put certain of the variants into production. 

The alphabetical designations were not in accordance with the standard form of notation of mark numbers. So the two models for production, the Spitfire D and Spitfire G, became in production. The Spitfire P.R.MkXI and Spitfire P.R.Mk.Vll (since D and G are the fourth and seventh letters of the alphabet respectively). Whereas the Spitfire A-G series had been powered by Merlin II, III or XII motors (being Spitfire I or II conversions), the Spitfire P.R.Mk.Vll, 229 of which were produced, had variously a Merlin 45, 46, 50, 50A, 55 or 56, and also provision was made in the production versions for an oblique F.24 camera. 

Provision was made for tropicalization and a number of Spitfire P.R.Mk.IV's was used in the Middle East. The Spitfire P.R.Mk.Vll, which had no provision for tropicalization, was powered by a Merlin 45 or 46. The last Spitfire for which Heston Aircraft was responsible was the Spitfire P.R.Mk.XIII, a low-level fighting scout generally similar to the P.R.Mk.VII. Prior to starting conversion of Spitfire V's to XIIl's, Heston Aircraft modified the last two Spitfire Gs up to XIII standard, but fitted them with Merlin 45 motors. 

The P.R.Mk.XIII was powered by a 1,620 h.p. Merlin 32 motor, driving a four-blade Rotol airscrew, and was armed in all cases with only four 0.303-in, machine-guns. It was the first P.R. type to have provision for a flat belly drop tank of standard Spitfire type, a 30-gallon tank being applicable, camera installation was two independent vertical F.24 (5-in.), (8-in.), (14-in.), (20-in.) or (20-in. Telephoto), and one port or starboard oblique F.24 (5-in.), (8-in.). (14-in.) or (20-in,). Instead of the cockpit teardrops, a balloon hood was fitted, and the windscreen was bullet proof. Only twenty-live Spitfire P.R.Mk.XIII's were produced, these all being converted by Heston Aircraft Co., Ltd., the first seven from Spitfire VAS and the last eighteen from Spitfire VBS.

More to follow soon......


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## Wurger (May 14, 2006)

Hi mfg !!!
A good part of the Spitfire history.I like it.
Gut arbeit.


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## Gnomey (May 14, 2006)

Interesting read mfg!


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## mfg (May 14, 2006)

Thank you


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## helmitsmit (May 14, 2006)

When you get more stuff let us know. What was the speed of those early spits


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## the lancaster kicks ass (May 15, 2006)

interestingly the F.24 was also used by bomber command to photograpgh the point at which the bombs were dropped, in the lanc it's the clear circle just infront of the bomb bay, but behind the red line..........

source- lord knows.............


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## mfg (May 15, 2006)

helmitsmit said:


> When you get more stuff let us know. What was the speed of those early spits



The early PR Mk's A to C were based on the original Mk1 airframe, the Mk1a fighter had a max speed of 367 mph

PR MkD (later called PRIV) used the Merlin 45 engine that was fitted to the MkV fighter and had a top speed of 372 mph

PR VII again used a Merlin 45 but had a speed of 368 mph

PR X - Merlin 64 or 77 top speed 416 mph

PR XI - used a number of engines Merlin 61,63,63A or 70 - top speed 442 mph

PR XIII - used the Merlin 32 which gave a top speed of 348 mph

PRXIX - used a Griffon 66 which gave a speed of 445 mph at 26,000 ft.


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## mfg (May 16, 2006)

The last and the greatest photographic reconnaissance variant of the Spitfire was the PRXIX.

It was powered by the Griffon 66 engine, with a max ceiling of 42,000ft. Its normal safe range was 1,160 miles, but this was extended to 1,550 miles by adding a 170 gallon overloaded drop-tank.

She could have a number of camera fits, listed below are the common ones:

1. Split pair of vertical F24 cameras with 14in or 20in lenses, one oblique F24 camera, fitted with either 8in or 14in lenses

2. Spilt pair of vertical F8 or F52 20in lens cameras.

3. Spit pair of vertical F52 36in lens camera 

Some 225 models came off the assembly lines with production ending early 1946, but the aircraft was used in front-line photo reconnaissance service with the RAF until April 1954.

In fact the last time a Spitfire PRXIX was used to perform an operation act was in 1963 when one was used in battle trials against an English Electric Lightning to determine if a RAF Lightning could take on a piston engined aircraft. 
This information was required because the RAF jets might have to engage P-51 Mustangs in the Indonesian conflict of the time.


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## helmitsmit (May 16, 2006)

That info about the mk1d looks wierd wouldn't it do about 10mph faster than the standard fighter mk1?

I thought the mkXI did only 421mph?


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## mfg (May 16, 2006)

The PR ID was a special long range with leading edge wing tank + 30 gallon fuselage tank, it carried so much fuel that it was nicknamed "the bowser". Early production models were very badly balanced and consequently difficult to fly. Later models were better balanced, had the more powerful Merlin 45 engine as used by the Mk.V

For the PR XI, which was an upgraded Mk IX and some Mk X’s, I have seen speeds ranging from 401 to 442 listed in my reference books and the internet.


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## helmitsmit (May 16, 2006)

fair enough. good info. Do you know the highest the Mk XIX ever opperated at? I've heard reports of 50,000ft???


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## mfg (May 16, 2006)

The highest speed ever "officially" accomplished in a dive by a propeller driven aircraft was by Flt Lt. Ted Powles, RAF, in a Spitfire Mk.XIX at 690 mph or .94 mach. in an emergency power dive from a true altitude of 51,550 feet. 
This occurred on 05 Feb, 1952. 
This his accomplishment was kept "Secret" by the British Gov't. for undisclosed reasons. It is now unclassified. 

Follow the link for more info on  Flt Lt Powles


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## helmitsmit (May 16, 2006)

mfg said:


> The highest speed ever "officially" accomplished in a dive by a propeller driven aircraft was by Flt Lt. Ted Powles, RAF, in a Spitfire Mk.XIX at 690 mph or .94 mach. in an emergency power dive from a true altitude of 51,550 feet.
> This occurred on 05 Feb, 1952.
> This his accomplishment was kept "Secret" by the British Gov't. for undisclosed reasons. It is now unclassified.
> 
> Follow the link for more info on  Flt Lt Powles


I heard about that. So it didn't get past the sound barrier


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## syscom3 (May 16, 2006)

I read somewhere many years ago, that the RAF (maybe the French participated too?) in a high altitude aerial survey of Germany in the months leading up to the start of the war.

Supposedly it was done in secret and the recon aircraft was skillfully camoflaged as to remain unobserved during its transits.

Anyone know of this? Was it true?


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## Twitch (May 16, 2006)

690 in a Spit. HAHAHAHAHAHAHAHAHAHAHAHA! Get out the shovels, it's getting deep. If that's such a big deal how come Hub Zemke's group's Thunderbolts pegged their 700 MPH airspeed indicators in dives? That bogus web page doesn't mention anything about that or a 51,000 foot altitude.

They never operated at that altitude during the war for sure. Luftwaffe ace Wallter Schuck told me about how he finally got pissed at the high altitude recon Spits coming over his base unopposed and he lay in wait at 39,000 feet and smoked one.

I remember another bullcrap story from some German on the web saying how he broke the sound barrier in his 262. When I relayed the tale to General Yeager he peered out of his perpetually sqinted eye slits and in a monotone voice drawled, "262 can't do but Mach point 94, I tried it."


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## helmitsmit (May 24, 2006)

The spit did have the best critical mach number of the war.


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## Twitch (May 25, 2006)

How the hell could the light-weight Spit with its Dumbo sized wings dive with a 14,000-lb. P-47 or 18,000-lb. P-38 both of which exceeded 700 MPH. Hell the P-51 has a red line of 505 and although it was exceeded to some extent, no Mustang ever hit 690!

The record if it can be substantiated is a P-38 flown by Col. Cass Hough. Hough was in P-47s before his group switched to P-38s at Bovington. Allegedly he began a dive at 43,000 feet and leveled off at 25,000 after an indicated 780MPH.





If I'm going to believe in fairy tales I'll believe this one and not 690MPH Spits.


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## the lancaster kicks ass (May 25, 2006)

i'm not pilot but i'm fairly cirtain that in an extreme dive such as these whatever your indicated air speed reads as, it's proberly not your actual speed.........


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## helmitsmit (May 25, 2006)

the lancaster kicks *** said:


> i'm not pilot but i'm fairly cirtain that in an extreme dive such as these whatever your indicated air speed reads as, it's proberly not your actual speed.........



It was quite common for air-speed indicators to malfunction at speeds exceeding 550mph. It was proved scientifically that the spits wing was the must able to withstand near-mach 1 dives. The only way they know the spit fastest speed was because they measured it, secretly.


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## pbfoot (May 25, 2006)

helmitsmit said:


> It was quite common for air-speed indicators to malfunction at speeds exceeding 550mph. It was proved scientifically that the spits wing was the must able to withstand near-mach 1 dives. The only way they know the spit fastest speed was because they measured it, secretly.


When did "they" measure it and how and where And are "they" the same guys that say its gonna be a nice day I've always been curious as to who "they" are


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## the lancaster kicks ass (May 26, 2006)

i can't qualify this statement as it was a while back but i once saw a documentary that said it was thought the spit's airframe could withstand the stresses of mach 1.3, if she could be propelled to such a speed...........


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## helmitsmit (May 26, 2006)

the lancaster kicks *** said:


> i can't qualify this statement as it was a while back but i once saw a documentary that said it was thought the spit's airframe could withstand the stresses of mach 1.3, if she could be propelled to such a speed...........



The "they" mentioned above ws the R.A.F aircraft development unit. They tried the prolonged dives in 1954 with a MkXIX and in 1944 with a MkXI. However, there isn't anything on the Internet to prove it but I've got in a book. There were reports at a local police station that residents heard a loud bang high above them and a greenhouse actually shattered. Moments later they saw a lone spit heading back to base.


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## Hop (May 26, 2006)

> I read somewhere many years ago, that the RAF (maybe the French participated too?) in a high altitude aerial survey of Germany in the months leading up to the start of the war.
> 
> Supposedly it was done in secret and the recon aircraft was skillfully camoflaged as to remain unobserved during its transits.
> 
> Anyone know of this? Was it true?



Yes. Google for Sidney Cotton. He used a Lockheed Electra outfitted with cameras. He worked for MI6 though, not the RAF.



> The highest speed ever "officially" accomplished in a dive by a propeller driven aircraft was by Flt Lt. Ted Powles, RAF, in a Spitfire Mk.XIX at 690 mph or .94 mach. in an emergency power dive from a true altitude of 51,550 feet.



There's nothing official about that. It's a calculated figure, using some dubious assumptions.

The highest speed by a prop fighter officially recorded, and probably the highest reached with a successfull pullout (ie not including aircraft which broke up in the air) was mach 0.891 by a Spitfire XI piloted by Sqd ldr Tobin in 1944. That was 609 mph IAS.



> If that's such a big deal how come Hub Zemke's group's Thunderbolts pegged their 700 MPH airspeed indicators in dives?



Normal air speed indicators were not accurate in very high speed dives. P-38 pilots frequently reported exceeding the speed of sound in dives, they didn't come close either.



> How the hell could the light-weight Spit with its Dumbo sized wings dive with a 14,000-lb. P-47 or 18,000-lb. P-38



Because it had a higher critical mach, thanks to it's thinner wings. That means it experienced mach divergent drag at higher speeds than the P-47 or P-38 (the P-38 was in fact one of the worst fighters at high mach numbers, and had a very low limit)

This is from an RAE report about their dive tests:






Note the later onset of MDD, which quickly dwarfs all other forms of drag. In other words, above about mach 0.75 the Spitfire has less drag, despite it's large wings. That's the beauty of thin wings.



> The record if it can be substantiated is a P-38 flown by Col. Cass Hough. Hough was in P-47s before his group switched to P-38s at Bovington. Allegedly he began a dive at 43,000 feet and leveled off at 25,000 after an indicated 780MPH.



That's why it's no use relying on an ASI at very high speeds.

The P-38 had the lowest mach limit of the big 3 US fighters. The P-47 was next, the P-51 best. Both the P-38 and P-47 had to be fitted with dive recovery flaps because of their low critical mach.

The placarded limits were mach 0.68 for the P-38, 0.8 for the P-51B, somewhat lower for the P-51D, about 0.72 for the P-47 (iirc) and 0.85 for the Spitfire.



> When did "they" measure it and how and where



The Spitfire high speed dive trials were carried out by the Royal Aircraft Establishment at Farnborough. The various service limits I listed above were found by various test pilots, for both the USAAF and RAF.


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## helmitsmit (May 26, 2006)

Hop said:


> Yes. Google for Sidney Cotton. He used a Lockheed Electra outfitted with cameras. He worked for MI6 though, not the RAF.
> 
> 
> 
> ...



Thanks mate. That was what I was failing to explain. You put it much betterthen me! 

Didn't the Spit MkXI lose it's propellor after the dive but managed to glide back to base?


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## Hop (May 26, 2006)

> Didn't the Spit MkXI lose it's propellor after the dive but managed to glide back to base?



Not after this series of dives. 

The RAE report I have is dated Jan 1944. The Spitfire involved was EN409. The report notes that all the flights were carried out by squadron leader Tobin.

In February, piloted by squadron leader Martindale, the same Spitfire, EN409 suffered damage in a high speed dive. In late April, with Martindale flying again, EN409 lost it's prop and part of the engine in another dive. I have no idea what speed was reached on these subsequent dives. It might have been faster than mach 0.891, it might not. 

The US was carrying out similar research. In July 1944 they tested a Mustang at Wright Field. They carried out a series of dives, the fastest being mach 0.83. The buffeting was so strong they felt it was unsafe to try any higher speeds. The Mustang had suffered considerable structural damage and was written off.


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## helmitsmit (May 26, 2006)

Hop said:


> Not after this series of dives.
> 
> The RAE report I have is dated Jan 1944. The Spitfire involved was EN409. The report notes that all the flights were carried out by squadron leader Tobin.
> 
> ...



Good stuff! Is there any info of planes like the Tempest doing these test?


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## Twitch (May 26, 2006)

These Spitfires or Mustangs that MAY have hit 600 MPH in dives were popping rivets and more when they pulled out. Certainly they were in no condition to safely fly in combat again. 

I used the P-38 dive tale to show how silly stories can be believed, like 690MPH in a Spit. But now that figure has become 609 MPH?!

I can categorically tell you that 5 Thunderbolt aces personally described to me pegging the 700 MPH airspeed indicator as common. One was Hub Zemke and the other was Fred Christensen who did post war testing for Republic. He was an aero engineer as well. Gabby Gabreski described it. Bob "Shorty" Rankin did too.

I really doesn't matter what calculated drag factors are and the Mustang's laminar flow wings should have made it superior to all, in theory, but it wasn't. The proof was in the deed and the P-47s in practice had it all over P-51s or Spitfires in the ability to dive. Its tremendous weight, double a Spitfire's, coupled with it powerful 2,300 HP engine engaging the 4-blade paddleblade prop gave it initial inertia to accelerate to 700 easily. They did this ALL THE TIME.

As Bob Johnson also confirmed the Jug would not pull out under any circumstances until thicker air was hit at 8-12,000 feet. The Thunderbolts pulled out and almost never popped a rivet and had no structural damage. They were on the roster for combat the next day. 

I don't believe for one second that any Spitfire, Mustang or P-38 outdived the Thunderbolts. The men of the 56th dived at 700+ indicated on a regular basis and made no big deal out of it. These are guys I'll believe when it comes down to it.


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## Hop (May 27, 2006)

> Is there any info of planes like the Tempest doing these test?



Not high speed research flights, afaik, but I'm sure the RAE got their hands on one to try (they certainly tried Mustangs and P-47s as well). However, in 1946 the RAE wrote to Supermarine saying the Spitfire was the most suitable of all the aircraft they'd tried.

I do have the AFDU mach limit reccomendations for the Tempest V:

I.A.S. Height 
370 30,000 
410 25,000 
450 20,000 
490 15,000 
540 10,000 

The lower 540 mph figure should be treated with caution, as it might not be the effective limit of the plane. The AFDU are giving only mach limits, lower limits were often enforced at low level.

The AFDU limits for the P-51B:

I.A.S HEIGHT
298mph 35,000ft
336mph 30,000ft
376mph 25,000ft
422mph 20,000ft
468mph 15,000ft
520mph 10,000ft
574mph 5,000ft


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## Jabberwocky (May 28, 2006)

Depends what you mean by 'out dove'.

The P-51, P-38, P-47, FW-190 et al, had better INITIAL dive than the Spitfire, either through heavier weight, better aerodynamics or more power. 

However, the very thin wings and small frontal area of the Spitfire meant that once it got up into the high subsonic region, the Spitfire was actually a better diver than most of us have been lead to believe.


I have a post-war dive chart for a P-47D-30-RE:


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