There is, BTW, no such thing as "Muslim garb", any more than there is Jewish, Christian or Agnostic garb. A person may be wearing an Iranian chador, a Saudi or Afghan burqa, a Pakistani Salwar kameez, a Balinese sarong (ok, unlikely on an airplane), a taqiyah (skullcap), a hajib or a kaffiyah. Most likely, a Muslim man will be dressed like every other male around him.