Originally Posted by WHBM

Can I have a shot at this one.

Air Canada, Alia and Delta are already accounted for. I'll add BWIA as a fourth, coming from various Caribbean points.

I believe BA was operating them, although quite possible they were just shown in OAG as an L10, so that might actually make 7. BA had a poor history with the -500. They originally bought a fleet around 1980, then found they had no real use for them so after just a few years they were sold to the RAF. No sooner was that done than they started services to South America in a route swap arranged by the UK government to try and avoid British Caledonian's bankruptcy, which the -500s would have been ideal for, so BA leased the two aircraft which Sri Lankan carrier Air Lanka had recently supplemented their standard Tristar fleet with. The ones sold to the RAF were to replace their VC-10s - which in the event ran on together and the VC-10s lasted well over a further 25 years in service

Remaining two are a bit of a challenge. TAP of Portugal were regulars with them into Heathrow on odd flights, whether shown as such in the timetable or not. Alia had too many of them, and regularly operated Sudan Airways services to Europe with one, which might be timetabled as such. Finally, I don't know whether the OAG regarded RAF Brize Norton as a London airport. It's about 60 miles west, and is base for the quite well known RAF-operated public service from the UK to the Falklands, run at the time with those ex-BA aircraft (nowadays the service still runs from here but with chartered commercial aircraft).

I'll finally add (not one of the 6) that German charter operator LTU had a couple, used pretty constantly on holiday flights from Dusseldorf to the Caribbean, which if you craned your neck on a clear day and had a good pair of binoculars you could see transiting overhead London regularly. There weren't a lot of -500 operators, but goodness, you could see most of them here.

Great commentary as always Sir, and of course you are spot on as to the remaining L15 operators, those being BWIA, TAP and Sudan Airways.

Originally Posted by WHBM

What aircraft is shown on the BA nonstop service from London to Rio/Sao Paolo ? If it's a Tristar that would be beyond all except the -500.

Here's the schedule:

BA 245
Equipment: L10
Frequency: 246

London (LHR) to Rio de Janeiro (GIG) Depart: 2240 Arrive: 0810
Rio de Janeiro (GIG) to Sao Paulo (GRU) Depart: 0915 Arrive: 1015

Looking at the schedule between Rio and Sao Paulo back then, I can't help but daydream a bit and consider that if it were me flying to from London to Sao Paulo back then, I would've deplaned in Rio and then boarded the daily Trans Brazil 707 departing GIG for GRU at 1025. Another great option would've been to head over to the much smaller Santos Dumont Airport (SDU) where I could have connected to my choice of Electras from Varig or Vasp down to Sao Paulo's Congonhas Airport