I flew BAC-111s for BCal. They did not have passenger oxygen and I think because of that they were limited to FL 300.
There were a couple of great things about them. On the top of the wing they had gear down indicators for the main gear so if you did not get a green light for one of the main gear you could go back into the passenger cabin and look out at the wing and see if the indicator was visible.
If you were refueling and had ordered a certain amount of fuel the fuelling would shut off automatically when the target fuel was reached. If you then decided you wanted a bit more fuel you could press the fuel gauge test button. The indicators would wind down to zero and the fuel would start going on again. It was a great way to tweak the fuel if you wanted a bit more.
There was an ice detector which was a cog rotating on the side of the fuselage with a very narrow gap between the cog and a thin bit of metal above it. If any ice built up in the gap it stopped the cog rotating and brought on a warning light in the flight deck. Whoever was doing the walkround would hold the cog to stop it moving and the remaining pilot in the flight deck would give a thumb up when the warning light came on. Simple but efficient and a useful warning for airframe ice in flight.
And who could forget the Whiffletree! A whiffletree was a device used in the 19th Century, most commonly when 2 horses were pulling a plough. If one horse had less strength the whiffletree would automatically compensate so the plough could still go in a straight line, almost like rudder trim. When I did my BAC 111 ground school I learned that all British rear engined airliners like the VC10, Trident and BAC 111 had a system on the hydraulics called a whiffletree and if different hydraulic systems put out different pressures it compensated automatically.
Some accidents were mentioned earlier. There was also the BUA BAC-111 that took off from Milan and lost power in the right engine. A Captain in the jump seat told them to shut down the left engine which they did. With no power they stopped climbing at 250 feet and descended into a field. I would like to think that could not happen these days.
https://aviation-safety.net/database...?id=19690114-0