minyon on a plane
of course
but one has to use seichel
there are times when one needs to refrain from what would otherwise do when it will cause a chilul Hashem
and there are times when one must not
it is usually a shayla but one always has to use seichel and sometimes ask a Talmid Chochum
what Hashem wants comes first, ALWAYS, not what the goyim will think.
IF in this case it is better to risk possible unforseen disastrous events that may eventually arise from an innocent display of friendliness and warmth, then so be it.
if not, then so be it. but it is a consideration and a shayla.
a crucial one