I remember BEA Airtours had to place cards on the check-in desks advising passengers that their flights would be announced as "Tango". Like @Rog747 this mystified me, why not "BEA" or "Airtours" or even "Kilo Tango".
The Channel Airways Comet 4B fleet meanwhile were the bottom of the secondhand market, Sqn Ldr Jack Jones picked them up at effectively scrap prices. BEA Airtours had taken all the BEA mainline fleet, Channel bought the ex-Olympic Airways ones. These had long been run and maintained in a common pool with BEA, but in the last year Olympic really let them go, and I believe they had been stored at Athens for a while. They were the most disreputable-looking aircraft I have ever seen in mainline service, I recall one in 1971 at Manchester. Channel had patchily and minimally overpainted the remnants of the Olympic livery with blues and whites somewhat different in hue to the rest. They were subject to some lengthy summertime delays, which made the national press, although one of the reasons was suppressed, that Channel were On Stop for credit with some spares suppliers for not paying previous bills, not least the aircraft's manufacturer Hawker Siddeley, and were having to wait until funds were wired through.
A curious fact about Airtours Comets is their very first and last Comet commercial flights were by the same aircraft, G-ARJL.