The Hawker Siddeley Nimrod was direct development from the De Havilland Comet. Mainly designed for maritime operations, the Nimrod was the successor to the Avro Shackleton and took over the maritime role in the early 1970s. There were also 3 R1 Reconnaissance Nimrods built which replaced 51 Squadrons Comets at RAF Wyton, later moving to RAF Waddington, with another aircraft being converted to the R1 at a later date. Eleven aircraft were converted to the Airborne Early Warning and Control Role but were never put into service and were eventually used as spares for the rest of the fleet. In 1995, 32 Nimrods were upgraded to the MR2 standard and some of them continued operating at RAF Kinloss until 2010.