How do I pray on a plane?

First option, best when possible: pray standing in a free area of the cabin (near the galleys, with crew approval), facing the qibla at the start. On Gulf carriers and Saudia this is common — some aircraft even have a prayer area.

If impossible (turbulence, full flight, crew instructions): praying seated at your place is permitted out of necessity, bowing the torso for rukū‘ and slightly more for sujūd. Many scholars recommend repeating the prayer on arrival as a precaution; others consider it valid as is.

Third route, often simplest: use the traveller’s facilities and combine prayers (dhuhr+asr, maghrib+isha) before take-off or after landing when the time window allows. Prayer apps give in-flight times — you follow the time of the region you are flying over, and for breaking the fast, the sunset seen from the plane.