The entire flight time is three hours the flight time up to erewhon is 2 hours making flight time for remander of the trip is 1 hour so as long as i understood what your asking that is your answer
The question doesn't describe any experiment. If the same experiment is repeated, no matter how many times, the acceleration due to gravity will remain the same as it was during the non-existent original experiment, and will have no effect on anything.