No mention of the airlift in TEB Clarke's autobiography, but I found this interesting note concerning a cut at the insistence of the censor:

'A scene in the film contained a row between rival loudspeakers. Originally I had a sparrow alighting on the unpopular loudspeaker and, when flying away, leaving a small white mark on it as a payoff. Said the censor's directive, "The small white mark on the loudspeaker is not acceptable".'