Early photo-reconnaissance Spitfires[edit]Shortly before the Second World War startedFlg. Off.Maurice Longbottom submitted a paper to the Air Ministry in which he proposed that the RAF equip itself with small, unarmed aircraft which, stripped of unnecessary weight and equipped with cameras and extra fuel, could rely on high speed, a fast climb and high altitude to avoid enemy defences. He was thinking primarily about the Spitfire which, he argued, was the ideal aircraft for the role. Although his idea was received with interest, it was shelved because there were not yet enough Spitfires available to allow any to be diverted from equipping Fighter Command.When early operations proved the vulnerability of the Blenheims and Lysanders, in October 1939 the AustralianSidney Cotton,Acting Wing Commanderof the newly formed and highly secret "HestonFlight", met withAir Chief MarshalHugh Dowding, AOC of Fighter Command and persuaded him to release two Spitfires to his unit.[123]Cotton had already proved Longbottom's theory to be right in practice by using a modifiedLockheed 12Aon clandestine photo-reconnaissance missions over Germany.[122]The two Spitfires were "Cottonised" by removing the radio, stripping out the armament, and adding downward-facingF24 cameraswith 5" lenses to replace the inner-wing guns. All panel lines and the gun-ports were filled in withplaster of Parisand a special light "Camoutint Green" was applied to the aircraft which was then polished. Thus modified, the Spitfire was capable of reaching over 390mph.[124]While the fighter versions of the Spitfire stayed in Britain, the first PR missions were flown from bases in France by Cotton's unit which was renamed "No. 2 Camouflage Unit". The first RAF high-speed, high-altitude photo-reconnaissance mission of the war took place on 18 November 1939 whenFlt. Lt."Shorty" Longbottom took off fromSeclinand attempted to photographAachenfrom 33,000ft (10,000m).[17]After the initial successes of these aircraft more Mk I Spitfires were converted in different ways to accomplish different types of reconnaissance missions. On 17 January 1940, 2 Camouflage Unit was renamed the "Photographic Development Unit" (PDU), while another PR Unit,212 Squadronwas formed in France.[125]Five months later, on 17 June 1940, Sidney Cotton was removed from his role in the RAF for taking money to fly a French businessman to the UK while he was evacuating British agents from Paris. In the following year, he was awarded anOBEin recognition of his contribution to the development of photographic reconnaissance.[126]The PDU was expanded, eventually becoming1 Photographic Reconnaissance Unit(1 PRU) in November 1940, operating fromRAF Bensonas part ofRAF Coastal Command.On 3 June 1940,HauptmannWerner MldersofIII./JG5