Originally Posted by Toshbaf

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”?
SAA, Iran Air & Syrian Air identified

I flew aboard a TWA 747SP in early January 1986, likely N57203. Let's go with TWA and Aerolineas Argentinas

Both airlines seem quite plausible and in fact I even double checked when researching this question re. TWA. Aerolineas was apparently getting the job done with its -200Bs, the SPs showing up on the polar route to Auckland and even a comparatively short flight to MIA. In any event, as of December of '86, neither TW nor AR were running 74Ls into LHR.

Please, guess again!