I have prayed with talit and tefillin on many flights over the years. Sometimes the crew have found me a quiet corner and sometimes not. I have also prayed in a Swiss arrivals lounge, a Brussels Airways lounge and (twice) in a transit lounge at CDG. I have never received any negative comments about this. Praying on an aircraft is always a 'last resort', but is often unavoidable, particularly on West->East longhaul routes.