LU: The Mechaber states it is a preference to stand when possible (See Mishna Berurah Siman Kuf Yud Sif Daled):
http://www.hebrewbooks.org/pdfpager.aspx?req=49623&st=&pgnum=270
http://www.hebrewbooks.org/pdfpager.aspx?req=49623&st=&pgnum=271
As for travelling to the airport, it depends where one lives. Most people in NYC / 5 Towns do not recite tefillas haderech going to JFK or LGA.
And even if someone does say tefillas haderech to the airport, their is a special tfila printed in some siddurim/tehillim specifically for SEFINAS HA’AVIR (airplanes).