The "Snowpiercer" star admitted she was afraid to tell her co-star Tom Cruise about her fear of flying and only signed on to the movie at first because her character was not supposed to have any flight scenes.
Jennifer - who plays the sequel's female lead, a single mother who runs a local bar near the Navy base - told chat show host Graham Norton, "I was actually afraid to tell Tom at the time that I had only just recently talked myself out of a crippling fear of flying. When I signed on for the movie there was no flying for my character."
"I suddenly found myself taxiing on a runway in a tiny plane with Tom and he said, 'Have you been on a plane like this before? Have you ever done any aerobatic flying before?' "
She continued, "I started to get very nervous when he said, 'It will be very graceful and very elegant,' and that's how I found out I would be up in the P51 with Tom flying it!"
Meanwhile, Tom, 58, is famous for doing his own movie stunts but admitted this has led to "a lot of broken bones."
He said, "I am a very physical actor and I love doing them. I study and train and take a lot of time figuring it all out. I have broken a lot of bones!"
"The first time of any stunt is nerve-wracking, but it's also exhilarating. I have been told a few times during shooting a stunt to stop smiling."