B772:
As far as I know the talks of 1 FA on the F27 36 seater was very short lived. It bit the dust as soon as mooted to F/A unions. We did occaionally run with one F/A when the other went U/S. I did man the EW F27 galley on more than a few occasions when one of the F/A's was ill and it was fun but busy with a max of 36 even on a 52 seater.
The 1:36 is an over water requirement only as I understand it. over land I believe is allowed at 1:50.
The F28 4000s ran at 2 for 72, but the maximum souls on board was from memory 80 including crew and infants, and Agents that had not properly advised rugrats caused major problem. Kentucky Fried Trave were and I believe still are the worst offenders.
Ratlink is currently running under dispensation with the Q400 in 74 seat config so it is doable to get over the limit.
Eeenie Weenie tried running 3 FAs on the 4000, but they just got in each others way. The girls and guys chose to go with two.
As for the safety aspect, look at the SQ accident with Sierra Papa Kilo at TPE. The SQ crews carry a more than adequate compliment of cabin crew, but the tiny girls were unable to crack some of the exits without the help of normal sized humans.
To a large degree it is a case of available grunt in a given FA.
I would rather fly with the current crew of experienced QF link and QF mainline healthy fit F/A's than delicate little 55kg flowers who need someone to save them. That sort of mindset invalidates pax/slf ratios.
1:50 is fine, but on longer sectors but preferably not over water in my humble ground-bound opinion.
Best all
EWL