How did the Lockheed P2V Neptune compare with the Avro Shackleton?
Short answerThere was not enough difference to decide purely on performance, so the aircraft that best supported domestic industry would be attractive.
NotesThe Neptune and Shackleton were close enough in performance that domestic industrial benefit could decide between them. Numbers mattered more than a marginal technical advantage because enough airframes were needed for deployment, training, and maintenance at the same time. A proposed force of joint Royal Navy and Royal Air Force P-8 squadrons, with flights in Scotland, Gibraltar, and the Falklands, shows how procurement totals determine sustained coverage. Buying the full planned fleet of 197 Neptunes would probably have removed the case for building Shackletons, since one large purchase could displace a broadly comparable domestic type.