1.Flight Attendants clinging to the ground outside the aircraft
  2.Maintenance personnel working on the fuselage with a staple gun
  3.Pilot inquiring as to the location of the clutch pedal
  4.Signs over boarding gates reading, "Last Chance"
  5.Travel insurance stub mailers pre-addressed "Next of Kin"
  6.Rod Serling
  7.Complimentary packets containing blindfolds and individually wrapped cigarettes
  8.Fingernail scratch marks on outside of cockpit entrance
  9.Catholic Airline personnel receiving Last Rites
 10.Signs on aircraft engines reading, "Out of Order"
 11.Flat tires on landing gear
 12.Telltale signs from previous flights such as finger-like impressions on armrests and telltale stains on seat cushions.
 13.Building materials or debris embedded in nose, wings or undercarriage of aircraft such as roofing shingles, tree bark, aluminum siding
 14.Vacant engine mounts on wings or tail section of fuselage
 15.People in strange native garb dancing about the aircraft and shaking rattles, throwing powders, wearing masks or carrying spears.
 16.Any passenger tickets marked, "Destination: Uncertain"
 17.Optional seating sections marked, "Smoking/Non-Smoking/Flaming"
 18.Passenger instruction booklets reading, "In the event of emergency, repeat the following: 'Our Father . . .' "
 19.Rodents jumping from aircraft exits
 20.Pilots or Navigators carrying AAA Trip Tickets