Originally Posted by DingerX
Unlike the BAC, however, it's a benchmark that seems to get more generous with each generation of aircraft. That does not make the planes "less safe".
Didn't it use to be 45 seconds?
Actually, evacuation demonstrations were first required to be conducted in the US - 1965 I believe - and it was the air carrier that had to conduct them. It wasn't for another two years before the certification standard was put in place to require the manufacturer to conduct the demonstration.
The timing was originally 120 seconds, likely to account for the "state of the art" canvass chutes that were in use at the time, which required a couple of able-bodied folks to climb down ropes and hold the chute at the bottom.
The 90-second benchmark was introduced some time around 1967.