59 aircraft of the RAF Multi-Engine fleet that are planned to be in service on 31 March 2009 have Weapons System Officers (Navigator) (WSO(Nav)) as part of the crew. These comprise the Hercules C130K, VC10, Sentry, Sentinel, Nimrod MR2 and Nimrod R1 aircraft.
63 aircraft of the RAF Multi-Engine fleet that are planned to be in service on 31 March 2009 have Air Engineers as part of the crew. These comprise the Hercules C130K, Tristar, VC10, Sentry, Nimrod MR2 and Nimrod R1 aircraft.
Navigators form a sub-branch of the weapon system officer specialisation and flight engineers are more correctly known as air engineers. Currently there are 285 weapon system officer (navigators) and 175 air engineers available to serve in multi-engine aircraft1. These figures include personnel who are currently trained and qualified to serve in a multi-engine aircraft, those who occupy another type of flying appointment and those who occupy a non-flying post. Those in the last two categories would require refresher training before they would be available to serve in multi-engine aircraft.
1 Figures have been rounded to the nearest five.