Is it permissible for a traveler to combine the Maghrib and Isha prayers by delaying them if the call to Maghrib prayer is made while he is on the plane, knowing that he will still be traveling after disembarking, and that the discretionary time for Isha prayer will not have ended upon his arrival home?

If one's journey does not end until the time for 'Isha' (night prayer) begins, then it is permissible to combine Maghrib (sunset prayer) and 'Isha' with a delayed combination (jam' ta'khir), whether one prays them at the airport or at home. However, it is not permissible to shorten the 'Isha' prayer if one delays it until after the journey has ended.