I posted this on the PVR thread, reminds me of Hotel California "You can check out, but you can never leave..."
258. In addition to members of the reserve air forces who are liable to call-out as described above certain officers and former airmen may be recalled for service in the Royal Air Force. The difference from call-out is that they rejoin the Royal Air Force rather than serve in the reserve air forces (sections 65 - 77 and Chapter 2 of AP3392, Vol. 7). Once recalled, they must serve until released.
259. Liability to be recalled for service. Recall applies to any person not serving in the Royal Navy, the Royal Marines, the Army or the Royal Air Force or the reserve forces who:
a. Holds a commission as an officer, or
b. Has served as an airman, is under the age of 55, has not become an officer and it is not more than 18 years since he was discharged or transferred to the reserve (section 66).
260. The provisions of the 1996 Act do not apply to any person who became an officer or enlisted in the Royal Air Force before that Act came into force. Such personnel remain liable to recall under the Reserve Forces Act 1980 unless they have elected to be subject to the new provisions or have re-enlisted, re-engaged or extended their service after that date (s.66(6)).
261. Personnel recalled may be liable to serve anywhere in the world unless when they were last members of the Royal Air Force they were liable to serve only in the United Kingdom or any part of it.
262. Power to authorise recall for national danger, great emergency or attack on the UK. Her Majesty may make a recall Order, signed by the Secretary of State, when it appears to her that national danger is imminent or that a great emergency has arisen, or in the event of an actual or apprehended attack on the United Kingdom. It does not therefore apply to warlike operations, peacekeeping or humanitarian operations.
a. The making of an order must be reported to each House of Parliament immediately. Parliament must assemble within five days if it would not otherwise met.
b. Anyone recalled is entitled to be released (officers) or discharged (airmen) when his aggregate called-out or recalled amounts to three years in the previous six years, although the three years may be extended to five by order. Anyone may agree to serve beyond the set limit.
263. The 1996 Act sets out detailed provisions concerning the recall of personnel, their acceptance into, release and discharge from, service under a recall order.
from the RAF legal Service website at this link (RAF - Page not found).
The 1996 Reserve Forces Act (Reserve Forces Act 1996)
Gives the following authority for recall:
(1) Her Majesty may make an order authorising the recall under this Part of persons to whom section 66 applies—
(a) if it appears to Her that national danger is imminent or that a great emergency has arisen; or
(b) in the event of an actual or apprehended attack on the United Kingdom.
whereas authority to call out the reserves for:
(1) Her Majesty may make an order authorising the call out under this Part of members of a reserve force—
(a) if it appears to Her that national danger is imminent or that a great emergency has arisen; or
(b) in the event of an actual or apprehended attack on the United Kingdom.
or
(1) The Secretary of State may make an order authorising the calling out of members of a reserve force if it appears to him that warlike operations are in preparation or progress.
or
(1) The Secretary of State may make an order authorising the calling out of members of a reserve force if it appears to him that it is necessary or desirable to use armed forces—
(a) on operations outside the United Kingdom for the protection of life or property