mfg
Airman
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......
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......
