Gomer,
May I have another question - we are all aware that FAR 135.183(d) does not require you to work out your en-route performance (as you are carrying emergency floats), and as I know, from experience, that the early marks of the S76 start to gross out at about 20ºC, can we assume that you also do not work out a take-off weight that gives stay-up in the case of an engine-failure - i.e. you are operating in PC3 not PC2.
(In answer to ‘gomex’s’ earlier comment, there was a Bo105 that ditched in the GOM after losing one engine - round about January last year.)