Pax B and Bergerie
I would agree with practically all posted having been in the first group to transfer from BEA to BOAC after the formation of BA. The differences were astonishing especially flying two UK built aircraft but I would disagree with the hypothesis that BEA had more accidents because of the relative higher number of sectors.
The VC10 manuals were SO different to the Trident and both had deficiencies as did some other foreign aircraft that I flew. What was very different was our treatment as grown ups in BOAC and not just being copilots. Things had changed after the 747 did a touch and go through the plantation in KL and I had the ten in part 1.
Both had union troubles in the 70s, Tebbit grounding the 747 and the terrible atmosphere which was partly responsible for Staines.
I did get the impression that the rivalry was one sided with BEA mistakenly considering themselves superior.
I later experienced flying short haul to poorly equipped countries both in Eastern Europe and Africa as well as long haul with similar problems. One notable trip was to Conakry just after another coup which left the old regime hanging from a bridge. A Palace in the circuit equipped with anti aircraft batteries with a note that we would be shot down if we infringed the airspace, a notam that there was a trench 1/3rd of the way down the runway ( it had been filled in but with orange soil across the runway which we didn't know) and Chinese ATC whose French and English was unintelligible.
Another was into Tirana when it first started to open with non precision approach..ndb..thunderstorms..mountains and trying to determine our position using weather radar for the coast outline with a nav display that dropped out (it would only work with two DMEs.)
It comes down to training, professionalism and preparation; BOAC with briefing notes and having your own flight manuals. The offer of backsheesh simulator time on the ten. In BEA you picked the flight manuals up at check in and often you had to check if the procedures were correct as BEA used letraset to produce them. (BOAC had an early computer system).
The other big differences were the lack of dozens of carry forwards on the ten and the better crew relationships.
Finally whilst I flew both monitored approach systems that the non handling pilot did the throttles and only auto throttle unless there was an engine failure I found bizarre at best.