Project history
At RAF Honington, B-17F and B-17G Flying Fortress bombers were stripped of all normal combat armament and all other non-essential gear (armor, turrets and guns, bomb racks, radio transceiver, seats, etc.), relieving them of about 12,000 lb (5,400 kg) of weight. To allow easier exit when the pilot and co-pilot were to parachute out, the usual escape hatch was removed and the opening enlarged and modified for quicker egress, and on some aircraft the cockpit roof was removed.
The aircraft were fitted out at Burtonwood in Cheshire (the major servicing station for all USAAF aircraft in the UK) with Azon radio remote-control equipment. Azon (a contraction of "azimuth only") could only provide one axis of movement so two sets were needed in each drone aircraft. Two television cameras were fitted: one in the cockpit to show the main instrumentation panel and one in the nose to show a forward view during the target run, to be transmitted back to an accompanying B-17 "CQ-4" 'mothership'.[ citation needed ] [9] A precision radio altimeter, connected to the aircraft's C1 autopilot, was fitted. A whip aerial on the nose received control signals, and an antenna on the tail gun position transmitted the camera signal. To improve reception, the mother ship had a directional receiving aerial. A smoke canister under the aircraft could be used to leave a trail to improve observation by the mother ship. The drone was loaded with explosives weighing more than twice that of a B-17's normal bomb payload. The British Torpex ("Torpedo Explosive") used for the purpose was 50% more powerful than TNT alone. [10] [a] The control equipment was wrapped with primer cord to ensure its destruction. [11]
When the training program was complete, the 562nd Squadron had ten drones and four 'motherships' (three B-24s and a B-17G). On missions, the drone and its two motherships were accompanied by a small fighter escort (eight P-47s) and supported by a Mosquito flying ahead reporting on the weather. [12]
A relatively remote location in Norfolk, RAF Fersfield, was the launch site. Initially, RAF Woodbridge to the south in Suffolk had been selected for its long runway, but the possibility of collision between a loaded drone and damaged aircraft that diverted to Woodbridge caused concern. [b] Fersfield was allocated to the USAAF but otherwise unoccupied, and the transfer was made in July. At Fersfield they were joined by the US Navy's Special Air Unit No.1 (with volunteers drawn from maritime patrol units at Dunkeswell) and a Wright Airfield detachment working with television-guided bombs (codenamed "Batty")
The remote control system was insufficient for safe takeoff, so each drone was taken aloft by a volunteer crew of a pilot and a flight engineer to an altitude of 2,000 ft (600 m) before transfer of control to the CQ-4 operators. After successful turnover of control of the drone, the two-man crew would arm the payload and parachute out of the cockpit. The 'mothership' would then direct the missile to the target.[ citation needed ]
After failures in early August, the "double Azon" system was replaced with an improved system brought from the US and missions were paused while this was installed and tested. Aircraft with this fitted had the codename "Castor". [13] The system was a single transmitter in the mother aircraft and a receiver in the 'robot'. The first missions with the Castor was on 11 September 1944. There had also been modifications to improve visibility of the drone: Eureka/Rebecca radio equipment for the mother to home onto, the smoke dispenser (controlled by radio signal), and painting the upper surfaces of the drone yellow. [13]
For Anvil missions, the US Navy provided their own controller aircraft, two Lockheed PV-1, [13] and a B-17 accompanied it to receive the television signals.[ citation needed ]
The Castor missions were targeted against enemy installations that did not require long flights over enemy territory so reducing likelihood of the drone being brought down by flak. The mother ships flew a different profile than before- now at same altitude as the drone ( 2,000 - 2,500 ft) but a couple of miles behind, then letting the gap increase to about six miles in the run in on the target. In late October the targets for the remaining drones were changed to industrial sites deep in enemy territory. Remote control of the throttles was added so the drone could be flown at a higher altitude (10,000 ft) before dropping to a lower one for the actual attack. [14]
After the Anvil and Batty projects had left Fersfield, operations were transferred by the 3rd Division to the unit's parent base at RAF Knettishall, a few miles to the West and over the border in Suffolk, and missions from there began in December. [14]
The USAAF wanted to transfer the program to the continent to attack industrial targets but the UK objected to this use of the drone in light of V-2 attacks on Britain. Approval was given in January but then rescinded before the end of the month. [14] The program effectively ceased on 27 January 1945 when General Spaatz, (C-in-C USSTAF) sent an urgent message to Doolittle: "Aphrodite babies must not be launched against the enemy until further orders". [15] [5] The USSTAF made representations to President Roosevelt about use of Aphrodite against the Ruhr and a presidential telegram to Churchill on 31 March received a cautious agreement in April. However, the imminent end of the war in Europe led to the project being formally ended on 27 April. [14]
It had been hoped that Operation Aphrodite and Operation Anvil would match the British success with 5-ton Tallboy and 10-ton Grand Slam ground penetration ("earthquake") bombs but the project was dangerous, expensive and ultimately unsuccessful. Of 14 missions flown, none resulted in the successful destruction of a target. Many aircraft lost control and crashed or were shot down by flak, and many pilots were killed, though a handful of aircraft scored near misses. One notable pilot death was that of Lieutenant Joseph P. Kennedy, Jr., USNR, son of the former US Ambassador to the UK, who was expected to have a political career in the US and was the elder brother of future US President John F. Kennedy.
