is it permissible for a Muslim who travels by plane or bus to offer Salah (Prayer) while sitting in their seat?
A Muslim who travels by bus or plane may combine between two Salahs, if the time of the first Salah becomes due before boarding, in case the airport or the bus station is located outside their city - which is an inconsiderable factor if the airport is located in another city because they are already on a travel - or after alight if they land before the time of the second Salah expires. (Part No. 6; Page No. 461) However, if flying on the plane will extend for a long time which will make it impossible to perform the two Salahs at the time of the earlier or the latter one on land, it is permitted to perform the Salah on board of the plane, the bus or the train according to ability. Allah (Exalted be He) says:
So keep your duty to Allâh and fear Him as much as you can
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.