The scheme your friend's son is after is described at
http://www.rafcareers.com/istherafforme/engineers.cfm
half way down.
However, if his year out is next academic year I fear he may be too late to apply; because of OASC and clearance lead times, the application deadline used to be at the end of Dec, though it may have changed in the couple of years since I left the recruiting world. The people with the gen are the Engineer Liaison Team at Cranditz; they are due to be disbanded, but I think they're still going. You can raise them on Cranwell 6491.