If a traveller is flying west from New York to Hong kong for 16 hour and needs to Daven mincha on the airplane, which time zone should he follow?
One should follow the time zone of the place over which one is flying at the time of davening.
See: Yerushalayim Be-Mo’adehah, p. 232, in the name of Rav Shlomo Zalman Auerbach; Iggros Moshe, Orach Chaim Vol. 3, no. 96.