Maybe if they ditched the overly long interview process they would find themselves a little more nimble, and able to respond to hiring needs in a semi-realtime manner? Why on earth do BA insist upon this 1930s method of hiring? Delta Airlines can interview and hire you in one day, United takes under a week to respond. Do a quick phone screen, email a link for a personality test. If all goes well, then it's down to LHR for a sim check and face-to-face. Maybe even throw two candidates in the simulator for an actual, airplane based "group exercise." (I know, this is crazy talk).
Give the candidates a hotel room for the night before (and a sandwich for lunch), in acknowledgment of their efforts, and call them in a max of 7 days with a yes/no.
Can it really be that hard?!
Alas, however, I feel that the above method would prove disastrous for management personnel.....