In March 2011, an Alaskan Airlines flight was met at LA airport by fire crews, foam trucks and FBI agents because three Jews on board were praying in tefillin, which, in our super-security conscious times, were judged by the crew to pose a terrorism risk.
What do we do when on an airplane and the time comes to pray? Maimonides is sympathetic to the needs of travellers who find themselves riding an animal when it is time for the morning prayers. “Someone who is riding his animal, even if he has someone who will hold his animal, need not get off. Rather, he should sit in his place and pray so that he feels composed” (Hilchot Tefilah 5:2).
Nowadays, most long-haul journeys do not involve animals. While it is a great mitzvah to pray as a group, it is a problem to disturb others by having a large number of people congregate and pray at the back of the plane, (usually near the toilets).
According to many authorities, it is better to recite even the silent Amidah seated on a plane rather than stand and risk creating a disturbance.