Biggles: Adventures in Time (1986)

Salesman Jim Ferguson, who is living in New York City in the present time, falls into a time hole and is transfered to 1917. It's turn out that his time-twin - James 'Biggles' Bigglesworth - is in mortal situation, and Jim is sent to help him. The job is to destroy the 'Sound Weapon' of the Germans, a mission that could cost their own life.