I once read a mystery novel by Tony Kenrick (published circa 1972) titled “A Tough One to Lose” in which a 747 jet with over 300 passengers aboard departs from Los Angeles International Airport and vanishes from radar screens over Lake Tahoe. A couple of hours later, the authorities receive an anonymous package containing some personal effects from some of the first-class passengers (as I recall, things like a wallet and an engraved watch) along with a note demanding a $25,000,000 ransom in uncut diamonds for the return of the plane and the passengers. The mystery is solved by the unlikely protagonists of the novel: a down-on-his-luck LA lawyer (who gets pulled into the case because one of his clients happens to be one of the missing passengers) and his secretary (who also happens to be the lawyer’s ex-wife). We eventually discover that the crime was committed by a team of crooks which included such people as a computer programmer, a bookmaker and some airport personnel. It turns out that all the economy-class passengers on the flight were part of the caper: deadbeat customers of the bookie who gave them airline tickets and told them he’d forgive their debts if they took the flight, did as they were told and kept their mouths shut. The only real passengers were the ones in first class: they were taken off the plane and locked into an airport boiler room before the plane even took off. When the flight was hijacked over Lake Tahoe (I forget the details on how this was done), it flew down to an altitude below radar level, then changed its transponder code to the identification number of a completely different (and fictitious) flight inbound for LAX, which the programmer had created in LAX’s computer systems so that the flight would not attract attention as it arrived. The aircraft landed, its fake passengers were de-planed, and the 747 was then taken to a hangar by unsuspecting airport servicing crews for what the maintenance schedule (rejiggered by the computer programmer) listed as a scheduled overhaul of its engines (or some such lengthy procedure that would keep the aircraft out of public view for a couple of weeks).
