If the Second World War proved anything, it was the vulnerability of the United Kingdom’s “Atlantic Lifeline” to submarine attack. During that conflict Coastal Command destroyed no less than 196 submarines, a good proportion of the overall total. After the war ended and the return of the various American types in Coastal Commands inventory only the Avro Lancaster or Avro Lincoln were available for this vital work. Accordingly a specification (R5/46) for a long range maritime reconnaissance aircraft was issued in 1946. The new aircraft, designed by the great Roy Chadwick was developed from the Avro Lincoln, (the Lincoln was essentially a “stretched” long range Lancaster). In order to accommodate the large crew, sensors and weaponry a new wide bodied fuselage was developed. The powerplants were four mighty Rolls Royce Griffons driving two contra-rotating three bladed propellors each. The name of the new aeroplane was “Shackleton”, perhaps the most heroic of all the polar explorers and was chosen by Chadwick himself.
The Avro Shackleton MR1 entered service with 120 Squadron in 1951. An improved version, the MR2 entered service soon after. The MR2 introduced various changes, a sharper more pointed nose with a bomb aimers position, twin 20mm cannon mounted in the extreme nose, and a lengthened tail with a lookout position to assess bombing accuracy. Most importantly the radar was moved from a chin position to a ventral position aft of the bomb bay. Many Shackleton pilots say that the MR2 was the nicest of the Shackleton family to fly. The final major variant was the MR3 which introduced a fully hydraulic nosewheel undercarriage, large tip tanks, improved internal furnishing and sound proofing. Because the weight of the Shackleton had risen from about 80,000 lb’s to over 100,000 lb’s two Armstrong Siddely Viper jet engines were added to the outboard nacelles to give that bit of extra whoomph for take off. The Shackleton served in the maritime reconnaisance role until the late 1960’s when it was finally replaced by the Nimrod.
One would think that the Shackleton story would end there, even when it entered service in 1951 it was an anachronism, by the early 1970’s it looked like ancient history. However the Royal Navy’s decision to scrap its large carrier’s including its Fairy Gannet AEW fleet had left a yawning gap in the United Kingdoms Airborne Early Warning capability. As a stop-gap solution low fatigue life Shackleton MR2’s were fitted with Fairy Gannet AEW kit under the forward fuselage. The Avro Shackleton AEW2 provided the United Kingdom’s airborne early warning capability until the early 1990’s when finally replaced by the Boeing AWACS system.