Passenger 1 (The Man from MI.5)

A passenger donning a grey suit was aboard the Fireflash flight in 1965 which took Lady Penelope Creighton-Ward from England to Nice so that she could meet with MI5 agent Jimmy Bondson. Towards the end of the journey, he was sat in the cocktail lounge. (TV: The Man from MI.5)

Other sources dated the activities of International Rescue to the 1990s, (PROSE: The Dying Days) the 2060s, (PROSE: Titan Declares War! et al.) and the 2080s. (PROSE: Captain Scarlet in Death Crash! et al.)

Behind the scenes
The puppet which "played" the passenger was also seen in several other episodes of Thunderbirds. It was most promimently seen as the recurring character Eddie Kerr played by Matt Zimmerman who appeared in City of Fire, The Mighty Atom, and The Impostors. It had other speaking roles as the first casino croupier in The Duchess Assignment where he was voiced by Peter Dyneley, as Hitchins in The Cham-Cham where he was voiced by David Graham, as Morrison in Security Hazard where he was again voiced by Graham, as a television reporter in Atlantic Inferno where he was voiced by Ray Barrett, and as Simms in Path of Destruction where he was voiced by Graham once more. The puppet appeared in a silent capacity as a Bank of England employee in Vault of Death, as a Satellite HQ operative in Cry Wolf, as another Fireflash passenger in The Duchess Assignment, as a photographed man in The Cham-Cham, as an Atalante café customer in Alias Mr. Hackenbacker, as a Space Board member and another reporter in the first film Thunderbirds Are Go and as a diner in the second film Thunderbird 6.