Location shooting in Hong Kong was refused by the country's government on the grounds of possible breach of the peace following demonstrations and propaganda campaigns mounted by Hong Kong communists claiming the film was anti Mao and anti Chinese consequently filming was transferred to Taiwan (Kine Weekly 7/12/68)
Was basis for TV show Search (1972), minus video feed, but accurate for implants for Peck.
Originally intended as a starring vehicle for Frank Sinatra.with Yul Brynner and Spencer Tracy co-starring.
Filmed in 1969, the airline used at the beginning was Malaysia-Singapore Airlines (MSA) which came into being in 1966 as a result of a joint ownership of the airline by the governments of Malaysia and Singapore. The airline ceased operations after 6 years in 1972 when both governments decided to set up their own national airlines. (Source Wikipedia)