The issue of prayers is not a simple one. The plane is very crowded and if you want to form a minyan, the only place big enough to do so is in the back of the plane next to the bathroom.
It is uncomfortable to daven next to the bathroom as well as to block access to the other passengers who wish to use the bathroom. I try to daven on land before boarding the plane when possible. Obviously, when a flight takes off from the U.S. at night and lands in Israel the following afternoon, you must daven shacharis on the plane.
There is a halachic ruling by Rabbi Aharon Yehuda Leib Shteinman that it is preferable to daven sitting down, but calmly, rather than standing up but lacking kavana (concentration.) The issue of praying with a minyan is not mentioned there, so it is best to advise with a Rabbi.