20. (1986) Per schedules reflected in an OAG from the spring of 1986, I’ve identified five airlines that fly the Boeing 747SP into London Heathrow. Can you do so without benefit of opening our “bible”?
This is a fun one... I'm going to go with South African, Saudia, Iran Air, Pan Am, and Syrian.
You've hit on three out of five, Joe.

South African, Iran Air and Syrian Air are
correct! Pan Am and Saudia are incorrect.
Hmm... what are the other two?