The aircraft used is shown in exterior shots to be a civil version of the Halifax bomber, but the lavish interior of the fuselage appears to be much too wide for that type, and the big square windows shown in interior shots are not present on the exterior. In fact, the aircraft shown in exteriors, G-AKEC, appears to have been used for freight, not for passengers.
During the parachute jump, Jennifer's long loose skirt is hanging straight down. In reality, it would be blown upwards.