Prayer in planes, ships and transports

The traveling passenger has expressly textual concessions: the Quran and Sunna regulated prayer on the mount long before the plane.

Prayer on the mount

If you fear, pray on foot or riding.sura al-Baqara 239

• The Prophet (may Allah's peace and blessings be upon him) prayed on his mount during voluntary journeys, toward the qibla or not per heading (al-Bukhari 1099); obligatory prayers in safety, he did on the ground.
• Modern application: a long-haul passenger may pray sitting, bowing and prostrating by signs, when the situation requires (turbulence, impossible space, critical time); otherwise standing in the aisle or rear remains possible on many flights.
• The direction: one turns the heart toward the qibla per one's knowledge; the turning plane changing direction during prayer does not invalidate per the majority.
• Ibn Baz (Fatawa Nur ala ad-Darb, pp. 77-80) details the protocol: short trip, pray at the destination or before leaving; long trip, pray aboard facing the qibla, turning with the aircraft for the obligatory, standing if possible else sitting, by virtue of "fear Allah as much as you can" (at-Taghabun 16); for the voluntary, the heading's direction suffices, like the Prophet on his mount.

Ship and train

The Prophet prayed on his camel and permitted prayer on ships (reported of Companions sailing): the moving vessel does not prevent prayer per the majority; train and coach follow the same rule, prioritizing stops when time allows.

Dar al-Ifta Misriyya (mufti Atiyya Saqr's fatwa, 1997, p. 484) rules for the plane: prayer in flight is valid, preferable on the ground when possible; Malikis set it aside mid-flight (the prostration must really touch the ground), the jumhur allows it; ablution with water or tayammum, qibla by compass or approximation, quadruple shortened to two rak'as, sitting if dizzy: it is not postponed to landing. The same mufti (p. 185): the train, ship or plane passenger able to move faces the qibla and follows it wherever it turns (rule taken from the four schools' fiqh); the car occupant, like the rider, alights if the stop is safe, else prays per his capacity.

Combining at tight hours

The Prophet combined dhuhr and asr, and maghrib and 'isha, in travel without rain nor need.al-Bukhari 1104 (Muslim 705 for detail)

• The traveler combines per his school: at the first's time (jam' taqdim) or the second's arrival (jam' ta'khir); Hanafis: no combining, but a wide window of time choice.
• Airport layovers: the transit passenger is treated by his real journey time; prayers happen in dedicated rooms.

Practical note

Three traveler reflexes: know each prayer's start time at the overflight's local time, ask crew for rear space, and use the concession (sitting, signs) without shame: it is a divine permission, not a hack.