"Tempus fugit" is Latin for "Time flies."
The old business card of his that Mulder finds says "United States Bureau of Investigation" instead of Federal Bureau of Investigation. This deliberate error was done since making fake FBI cards (even as a TV prop) is illegal. This is the same reason that Mulder's and Scully's badges in the opening credits say "Federal Bureau of Justice, United States Department of Investigation."
It won an Emmy Award for Outstanding Sound Editing for a Series.
The pseudonym Max Fenig (Scott Bellis) uses on his ill-fated flight is Paul Gidney. Gidney is the name of one of the Moon Men in the first adventure of The Bullwinkle Show (1959), titled "Jet Fuel Formula" (the other Moon Man is Cloyd).