FSAirlines

I have idea about Cabin Crew.

The FSEconomy have a nice calculation - than bigger aircraft then more additional cost for Crew:

2-14 seats (1 - 13 passengers)...... no crew needed ($0 per hour)
15-21 seats (13-19 passengers)..... First Officer needed ($100 per hour)
22-34 seats (20-32 passengers)..... First Officer and Flight Attendant needed ($200 per hour)
35-45 seats (33-42 passengers)..... First Officer and 2 cabin crew needed ($300 per hour)
46+ seats (43+ passengers)......... First Officexr and 3 cabin crew needed ($400 per hour)

In the FSAirlines would be interesting draw attention to this option, for example:

=> 100 passengers ~ 2 cabin crew needed
=> 200 passengers ~ 3 cabin crew needed
=> 300 passengers ~ 4 cabin crew needed

In order to considering the number of crew and flight duration was changing the parameter "Crew & catering costs" in flight report

Regards!