When someone is flying on an airplane how is shkiah worked out. Does it go according to the makom they are flying over if it’s before or after shkiah there, even though in the plane where they are in the air shkiah didn’t happen yet (or already passed.) In short do they go after where they are in terms of the ground below them or on the plane itself (please cite any relevant sources.)
Shkiyah depends on the place over which the airplane is flying.
See Yerushalayim Be-Mo’adehah, p. 232, in the name of Rav Shlomo Zalman Auerbach; see also Iggros Moshe, Orach Chaim Vol. 3, no. 96.