Hawker Siddeley P.139B

P.139B
Model of P.139B
Role	AEW and COD aircraft
National origin	United Kingdom
Manufacturer	Hawker Siddeley Aviation
Status	Cancelled 1966
Primary user	Royal Navy (Intended)

The Hawker Siddeley P.139B was a proposed airborne early warning aircraft intended to operate from aircraft carriers of the Royal Navy. The P.139B formed part of the a major equipment procurement plan for the RN in the 1960s intended to give the service a force of new, modern carriers capable of operating air groups consisting of equally modern aircraft. However, cuts in defence spending by the British Government in the mid-1960s meant that these proposals never came to fruition.

The early 1960s was the zenith of carrier operation for the Royal Navy, as it operated a total of five aircraft carriers, all with air groups consisting of what were then the most modern carrier aircraft available. However, despite significant modernisation programmes to try and ensure that the Royal Navy could keep pace, the speed of aircraft development, which led to carrier based aircraft increasing in size, was such that the Royal Navy's existing carrier fleet could not keep up. Owing to the relatively small size of the Royal Navy's aircraft carriers, with HMS Eagle the largest at 55,000 tons, it became necessary for the RN to consider a new generation of aircraft carriers capable of operating new modern aircraft in sufficient numbers to be viable as capable units.

To go with the proposed new aircraft carriers, the Fleet Air Arm planned the procurement of new aircraft to go with them. In terms of fixed wing aviation, the plan involved three separate areas:

In 1959, the FAA had begun to replace the obsolete Skyraider AEW.1 with a version of the Fairey Gannet antisubmarine aircraft that had been heavily modified to serve in the AEW role as the Fairey Gannet AEW.3. However, this was intended only as a stop-gap, as it saw the AN/APS-20 S-Band radar and associated equipment transplanted from the Skyraider to the Gannet. By the time the Gannet was entering service, the AN/APS-20 had been in use for 15 years, having first been developed during the Second World War. As a consequence, by the start of the 1960s it had begun to be superseded by more advanced systems, with the US Navy by then operating the E-1 Tracer with the AN/APS-82 radar, a development of the APS-20 that was ground stabilised and, through its moveable antenna, could determine target height. Even this though was seen as an interim solution, as a new, purpose built aircraft with an advanced pulse doppler radar was already in development.

...
Wikipedia