Royal Air Force Recce Units

Photographic Reconnaissance Units (PRUs)

PRU

On the 8th July 1940, the PDU became the first Unit carry the title Photographic Reconnaissance Unit (PRU). Coming under the operational control of RAF Coastal Command, the Unit was however, administered by 16 Group. It was divided into 4 flights planning to have in each four Spitfires and One Hudson. later 'E' Flight was added with eight Spitfires. St. Eval in Cornwell became the home of B Flight under the command of Flt Lt Clark. With A flight under Sqn Ldr D Wilson being station at Wick in Scotland, with two Flights remaining at Heston. The PRU also had an Experimental Trials Flight, they undertook the testing of the Spitfire PR.1D. By the end of July a fifth operational Flight was added. On the 27th December 1940, the PRU moved home to the RAF Benson in Oxfordshire, where it remain throughout the war.

No.1 PRU

With the formation of the other PRU's, the original PRU was given the title 1 PRU. However, throughout its life it was always known as the 'PRU'. The Unit maintained a steady vigil over the English Channel looking for any signs of a possible German invasion and also they undertook the hunt for Hitler's battleships. Another area the Unit was employed on was the assessment of the Germany Navy's U-boat construction. In March of 1941, the PRU received its first production Spitfire PR1D's, these aircraft were to became the work horse of the Unit for a number of years. Still undertaking the requirement to photograph the movements of the German Navy in was on the 20 May 41 that Pilot Officer Suckling returned from a sortie with images of the battleships Bismarck and Prinz Eugen, seven days later the Bismarck was located by the Royal Navy and sunk, however, the Prinz Eugen slipped away and remained undetected until she was photographed in Brest on the 4th June. On the 16th June 1941, 3 PRU (see below) was disbanded and all its resources were amalgamated with 1 PRU.
1 PRU received its first PR Mosquito (W4051) on the 13 July 1941 for air and camera testing. With the first operational mission being undertaken by this aircraft type on the 17 September, however, this was abandoned due to a power problem onboard the aircraft. It was not until two days later that the first imagery was received back at Benson from a PR Mosquito.
By the end of 1941 the Unit had a total of 73 aircraft, which would have been the number to outfit four fighter squadrons. It had aircraft based at Benson, Wick and Lecuhars in Scotland, St Eval in the Southwest of the country and overseas on the Rock of Gibraltar and of course, a Maintenance Flight at Benson, which carried out the modifications to bring aircraft up to PR standards and of course a training unit to train aircrew in the ways of photographic reconnaissance. A decision was made on the 19th October 1942 to reform 1 PRU into five PR Squadrons, 540, 541, 542, 543 & 544, however, all the personnel within the squadrons considered themselves as part of the PRU until the end of hostilities.

No.2 PRU

Formed on the 17th March 1941 at RAF Heliopolis, Egypt. It was planned to equip 2 PRU with two flights of Maryland aircraft, this was due to the fact that there were no spare reconnaissance Spitfires available for the new Unit. However, the consignment Marylands was sunk in transit from the United States. Quickly the Unit was supplied with a number of Hurricanes which were modified locally, fitting them with extra fuel tanks in the wings and cameras in the fuselage. Another aircraft that remained with the Unit was "Cloudy Joe" which was a specially modified Lockheed Hudson, it had fitted a fixed vertical F.24 camera and onboard it had a hand-held F.24 14" camera.
By August of 1942 the Unit had received PR Spitfires, operating eighteen in total, sorties with the Hurricanes slowly came to an end. Also arriving was the new F.52 camera. The Unit also undertook the the training of pilots in air photography, at first, the Unit very few aircrew who had undertaken air reconnaissance tasking.
The Units early role was to embark on high-level reconnaissance, however, it did share of duties with other Units, 60 Sqn South African Survey Flight, 1437 Flight, operating out of the Western Desert and 208 Sqn who used Hurricanes fitted with an oblique camera. Late these units were to be formed in the 285 Reconnaissance Wing. With the onward march of the German Afrika Korps in July 1942 2 PRU had to move Eastwards. Reconnaissance duties continued until in 1943 the Air Ministry gave orders for 2 PRU to be reformed as 680 Sqn.

No.3 PRU (Oakington)

On the 20th October 1940, the Air Ministry agreed to a request by Bomber Commands to form its own PRU. So No.3 PRU came to light on the 16th November 1940 at RAF Oakington in Cambridgeshire. The Unit was divided into two flights, A Flight for daylight reconnaissance and B Flight night photography.
One of its standing tasks was to obtain clear defined post attack imagery of targets at a suitable scale for Bomb Damage Assessment (BDA) interpretation by Bomber Command. On the 22nd November A Flight received its first Spitfire PR.1C (X4385) and within days it was undertaking operational sorties. In all A Flight used 5 Spitfire PR.1Cs, of which, 3 did not return from operational sorties. Also they they were equipped with 4 Spitfire PR.1Fs, again one was lost over Texel in 1941.
Of note about the Spitfires was that a number were fitted with cameras that had German lens attached. At this time the largest scale that could be obtained using a 20" focal length lens fitted to the standard 5" x 5" camera format, this was totally inadequate for BDA reporting, this was improved if the aircraft was fitted with the 7" x 7" format of the F.8 camera. However, the PRU was trying to obtain a number of 24" Fairchild cameras from the United States Army Air Force, however, these were not forthcoming. With luck, a Junkers Ju 88A reconnaissance aircraft suffering with engine problems was forced down at Oakington by 2 Hurricanes of 17 Squadron. With the help of Heston and the Royal Aircraft Establishment, the cameras and lens were removed and the 72 cm (30") focal length Zeiss lens were fitted to F.8 cameras. The first hybrid camera system was flown in a Spitfire PR.1C (X4383) on the 21st December 1940. The Hybrid cameras went on to be fitted to a number of the Flights Spitfires.
B Flight was tasked to look at the development of night photography, in late 1940, Bomber Command had only 3 cameras to share among 9 Squadrons of bombers to record bombing missions. So B Flight was equipped with 2 Wellington 1C aircraft (T2706 & T207), later to joined by another 2 aircraft after T2706 ditched off Felixstowe and T2707 force landed at Binsey. The overriding problem obtaining the imagery at night was the synchronisation of the camera, the F.24, with the flares that illuminated the target. So it fell to B Flight to test new camera systems. The Flight was successful in trailing the new photographic equipment and by the end of 1941 all Bomber Commands aircraft would be fitted with a system that gave the required results.
In January 1941 flying was stopped at Oakington due to heavy show and ten days later, the grass airfield was waterlogged and was considered unsuitable for Spitfire operations. So A Flight was detached to RAF Alconbury which had a metalled runway, for a period of 2 months. It was from this airfield that Squadron Leader Ogilvie became the first RAF pilot to over fly Berlin in daylight, flying a Spitfire equipped with Hybrid cameras he obtained 95 images of the city.
No.3 PRU had a very brief existence, in all only 8 months, on the 21st July 1941 the Unit moved to RAF Benson and within one month, No.3 PRU had been fully integrated into No.1 PRU.
In total 285 Spitfire and 13 Wellington operational sorties had been flow form Oakington and Alconbury and a further 11 Spitfires sorties were flown from Benson. After the move and integration the Wellington reconnaissance aircraft were "surplus to requirement" and were sent to Boscombe Downs to be used for various trails.

No.3 PRU (Calcutta)

Formed from No.5 PRU, 3 PRU came into being in 13th May 1942 with the aircraft located at Dum Dum near Calcutta. Equipped with Hurricanes fitted with three F.24 cameras and B-25C Mitchell's again fitted with F.24 cameras, also carrying a photographer onboard. By September of that year the Unit was equipped with only six Hurricane Mk.IIBs and with only two of their long range B-25Cs remained serviceable, the Unit required replace aircraft without delay. On the 10th October 1942 the first two reconnaissance Spitfire PR.IVs arrived (BP911 & BP935), at the very start there was a problem with the aircraft, they both required a major overhaul and checking the cameras it was found that they were carrying F.8 cameras and at this time Dum Dum could not process the large format of the film used in them. However, the first operational sortie by 3 PRU with a reconnaissance Spitfire was carried out on the 19th October over Mandalay, Scwebo and Maymo photographing the rail junctions and airfields, by the end of the month a further two Spitfires had arrived.
Now equipped with the Spitfire which could cover more targets than with the Hurricane,and for the remainder of 1942 the Unit collected imagery of Japanese installations in Burma, also covering the Islands of Andaman.
On the 25th January 1943 3 PRU was disbanded and then reformed as 681 PR Sqn.

No.4 PRU

Formed at RAF Benson on the 10th October 1942 No.4 PRU set sail for the Mediterranean. The ground support personnel boarding the SS Arcassia and set sail. At the same time, six photo reconnaissance Spitfires flew to Gibraltar and carried out sorties over Algiers, Oran and Casablanca in the run up to Operation TORCH, the invasion on North Africa. The Unit was installed in its new base, Maison Blanche in early November. During December the base was attacked by the Luftwaffe, 4 PRU lost a number of their reconnaissance Spitfires completely destroyed and others damaged. The photographic section was also damaged, killing one of the Corporals and wounding nine others, with three of these later dying of their wounds. The Luftwaffe was also a match for the Units' Spitfire PR.IVs, a number being intercepted before they could get close to their targets, some being shot down and others having to return to base. In late 1942 the Unit had lost six of its pilots along with their aircraft.
In April 1943 they started to receive PR Mosquitos, again flying from Maison Blanche, these aircraft were able to collect imagery over South France and Western Italy. It was at this time that the Air Ministry was looking at a total reorganization of all the PRUs'. They stated that there was a danger that various reconnaissance units could and would overlap tasking, thus wasting time and effort. It worked out that there were four reconnaissance units covering the Mediterranean and the Middle East, 1, 2 & 4 PRU's and 69 Squadron flying out of Malta and also the USAAF which had the 3rd US Photo Group based in North Africa flying Lightning reconnaissance aircraft. So on the 1st February 1943 No.4 PRU was disbanded and reformed as No.682 Squadron.

No.5 PRU

Under the commanded of Flight Lieutenant A C "Fatty" Pearson No.5 PRU was officially formed on the 11 April 1942 by Air Headquarters India, at Dum Dum near Calcutta. Equipped with Hurricanes and B-25 Mitchell's for long range reconnaissance. The B-25's were on order from the USA for the Dutch Air Force, however; due to circumstances in the East Indies, they were "appropriated" by the RAF and pressed into the reconnaissance role, they had all the armament removed, the mid-upper gun turret was substituted with an astrodome. A fan of three cameras were fitted behind the fuel tank now fitted in the bomb-bay and a forth camera was fitted further aft within the aircraft. As well as the normal flying crew of the aircraft, on operational sorties an additional crew member was taken, their duties were to oversee the cameras and also replace film magazines if required, volunteers from the Units photographic section would undertake this duty.
With the Unit increasing the number of aircraft it held, in May 1942 it divided into two flights, one being five B-25s and the other three Hurricanes. In the same month the whole Unit moved to Pandaveswar, in spite of this, aircraft returning from operational sorties would landed at Dum Dum so the exposed reconnaissance imagery could be transported to Barrackpore for processing and then interpretation.