Unpaid Leave for BA pilots has been available for the last 2 years. The unpaid leave is part of the Business Response Plan put into place to conserve cash after the events of Sept. 11 and is available to ALL staff.
Anybody who wants to apply puts forward their application with the dates they want off (3 months - 12 months available) and subject to manpower requirements it is granted. The most recent application window for flight crew closed about a month ago, but if they feel there is excess capacity there very well may be a further opportunity. Times are still tough for the airline so efforts to control costs are still at the forefront.
I took 6 months unpaid last winter, and whilst feeling much poorer, I would not have swapped it for anything. Had a incredible time travelling down through SE Asia, Oz & NZ. Refreshes the soul - recommend it to everybody
T'bug