All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
The prayer time for the passengers who are in a plane is the time when the prayer is due when they are on the plane, and the time of the country from where they travelled or the time of their destination country should not be considered. For instance if Fajr prayer is due while they are on the plane, it is an obligation on them to perform it, and when the sun is at its meridian, they should perform Thuhr prayer, and so forth. However, if they will land in a place where it would be possible for them to perform the prayer on the ground before its time is over, then they should wait until they will arrive there. Nonetheless, if they fear that the time of the prayer will elapse when they arrive there, they are obliged to perform it on the plane according to their ability.
The questioner should know that when travelling by plane, she could not reach the destination before the time of departure, because the plane is not faster than the revolving of the earth. If we presume that one is travelling westward, which means that the time there [in the west] is inferior from the time from where the plane departed, the difference of the time of the earth which is due to its revolving on itself, though, is faster than the speed of the plane, therefore, it is not possible to arrive one day before the day of departure, and it is not even possible to arrive at the same time of departure, unless a faster means of transportation [then the plane] is invented, but this is not available now.
Allaah Knows best.