I grossly over simplified, but sometimes 'simple' provides us the best analogy - fluid mechanics aside. As the last resort option (beyond having desirable sensor redundancy etc), GPS or INS could have been the only, albeit inaccurate substitute for air data available during the reported pitot icing. Can a 'bus pilot tell us what the safe operating airspeed margin 447 might have had at FL370?
Last edited by davionics; 28th May 2011 at 12:12.