بســــــــــــــــــــم الله الرحمٰن الرحيم
Question: how does a traveller pray on a moving vehicle?
Answer: it depends on what type of vehicle one is travelling in and what type of prayer one is praying.
First of all, it is worth mentioning that the Muslim traveller should strive to plan his trip in a way that makes it possible for him to pray his prayers on-ground rather than on-board. He should take advantage of the concession the Sacred Law has granted him to combine the Dhuhr and ‘Aṣr prayers together, as well as the Maghrib and ‘Ishā’ prayers together. (This isn't permitted in the Ḥanafī school, although Ḥanafīs may do "apparent combining" by, for example, praying Dhuhr close to the end of its time and then praying ‘Aṣr at the first of its time.)
At times though, even this isn't possible. In such cases when one must pray on-board, one must ensure that one is worshipping one's Lord in the correct manner and not fall into the mistakes that many lay-people fall into. In this regard we present the following.
Praying on a Plane
Nafl (Optional) Prayers
If the prayer is a nafl prayer:
• One may pray it seated.
• If possible, one must face the qiblah with one's chest throughout one's prayer. If not possible, one must do so when saying the opening takbīrah, following which one turns to face the plane's direction of travel for the rest of one's prayer. If not possible, one may simply face the plane's direction of travel from beginning to end.
• One does rukū‘ and sujūd when seated by inclining forward. If able to, one must incline further for one's sujūd than one does for rukū‘.
Farḍ Prayers
If the prayer is a farḍ prayer, then:
• One must pray it standing, facing the qiblah, and performing a complete rukū‘ and sujūd, by agreement of the four madh'habs (schools of Islamic law). This is indeed possible in some areas of the plane, such as the aircrew galleys besides the lavatories and in front of the emergency exit doors.
• Such a prayer, though, must then be reperformed as qaḍā’ once one has landed, and cannot be performed in jamā‘ah on the plane. This is according to the more correct (asaḥḥ) opinion of the Shāfi‘ī school, the reason being that istiqrār (being firmly settled on the ground) is one of the conditions of a farḍ prayer, this being absent when on a plane. This makes the reperformance of the prayer upon landing necessary, and any prayer that must eventually be reperformed cannot be prayed in jamā‘ah. However, according to Ḥanafī and Mālikī scholars, as well as in a second opinion within the Shāfi‘ī school, such a prayer need not be reperformed.
• If one cannot pray a farḍ prayer as such, one prays it however one is able to, seated or otherwise. However, one must then reperform it as qaḍā’ upon landing, by agreement of the scholars.
Praying on a Ship
All of the above likewise applies to praying on a ship, except that no qaḍā’ is required according to all schools if one performs the farḍ prayer complete with all its conditions and integrals.
Praying on a Bus, Train, or Car
As for prayers on a bus, train, or car:
• If it's possible to perform a farḍ prayer with all its conditions and integrals on the vehicle, one may do so, just as if one were on a ship.
• However, this is usually very difficult on a bus and train, and impossible in a car – in terms of facing the qiblah, standing, and performing a complete rukū‘ and sujūd – which means that in most cases, one will need to disembark so as to pray.
• If disembarking is not possible, one prays however one can on the vehicle and then makes up for it as qaḍā’ later on when able to.
• However, this is usually very difficult on a bus and train, and impossible in a car – in terms of facing the qiblah, standing, and performing a complete rukū‘ and sujūd – which means that in most cases, one will need to disembark so as to pray.
• If disembarking is not possible, one prays however one can on the vehicle and then makes up for it as qaḍā’ later on when able to.
Determining the Qiblah Direction and Prayer Times on One's Flight
The following site contains a handy calculator which can assist one in determining the qiblah direction and prayer times on one's flight: https://www.halaltrip.com/prayertimes/inflight/
One should use the "University of Islamic Sciences, Karachi" method for calculating Fajr and ‘Ishā’ as it is the most accurate of the listed methods. Also, it would be a good idea to search up the average cruising altitude of one's flight beforehand in order to get more accurate times.
And Allah knows best
وآخر دعوانا أن الحمد لله رب العالمين. وصلى الله على سيدنا محمد وعلى آخر وصحبه وسلَّم.
References
• Reliance of the Traveller, Sh. Nuh Ha Mim Keller (translation of ‘Umdat al-Sālik by Imām Aḥmad ibn Naqīb al-Miṣrī)
• التقريرات السديدة في المسائل المفيدة، للسيد حسن بن أحمد بن محمد الكاف
• http://islamqa.org/shafii/qibla-shafii/34250/praying-on-a-plane-2
• http://seekershub.org/ans-blog/2015/02/14/can-i-pray-in-a-car-how-to-pray-in-a-train/
• التقريرات السديدة في المسائل المفيدة، للسيد حسن بن أحمد بن محمد الكاف
• http://islamqa.org/shafii/qibla-shafii/34250/praying-on-a-plane-2
• http://seekershub.org/ans-blog/2015/02/14/can-i-pray-in-a-car-how-to-pray-in-a-train/