It is obligatory upon the Muslim who is upon an aeroplane when the prayer comes in to pray it to the best of his ability. So if he is able to pray standing, bow, , and prostrate, then he does so , and if he is not able then he prays sitting and he indicates his bowing and his prostrations. If he can find a place within the plane wherein he is able to stand and prostrate on the ground instead of indicating (these movements) then that is obligatory upon him, due to the statement of Allah, The Glorified and Exalted “So fear Allah as much as you are able,” [Surah At-Taghaboon : 16]
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Shaykh Abdul-Aziz Ibn Baaz | Authentic Statements

About Shaikh Abdul Azeez Ibn Abdullah Ibn Baz

Abdul Aziz ibn Abdullah ibn Baaz (Arabic: عبد العزيز بن عبد الله بن باز‎) (1910 - 1999), was a Saudi Arabian Islamic scholar.

Abu 'Abdullaah Shaykh 'Abdul-'Azeez ibn 'Abdullaah ibn 'Abdur-Rahmaan Aal-Baaz was born in the city of Riyadh in Dhul-Hijjah 1330 A.H./1909 C.E.

He acquired knowledge from many of thescholars of the Kingdom. Some of his teachers were Shaykh Muhammad ibn 'Abdul-Lateef Aal-Shaykh, Shaykh Saalih ibn 'Abdul-'Azeez Aal-Shaykh and the eminent Shaykh Muhammad ibn Ibraaheem Aal-Shaykh who, in his time, was the Muftee of Saudi Arabia. Shaykh Ibn Baaz accompanied the eminent Shaykh and learned from him for about ten years. Thus he gained his religious education from the family of Imaam Muhammad ibn 'Abdul-Wahhaab.

He was the Grand Mufti of Saudi Arabia from 1993 until his death in 1999.