What basis are you starting from? VIP or utility machine? Clear area profile or helipad?
These figures are based on real aircraft and might give you some idea of performance.
EC155B MTOW clear area VToss 60kts, SL +30degC = 4540kg
EC155B1 MTOW clear area VToss 60kts, SL +30degC = 4800kg
1. VIP machine with floats, air con:
Basic weight 3200kg
2 crew @ 85kg = 170kg
Gives a payload of 160kg (155B) or 420kg (155B1) and over 3 hours endurance at cruise speed (approx 150kts indicated) to tanks dry.
2. Utility machine with floats, external life rafts:
Basic weight 3050kg
2 crew @85kg = 170kg
Gives a payload of 310kg (155B) or 570kg (155B1) and over 3 hours endurance at cruise speed (approx 150kts indicated) to tanks dry.
Loads more info on 155B1 performance etc at:
http://www.eurocopter.com/site/docs_...s/TD_155B1.pdf
It's a really great pilots' machine, fantastic autopilot, super smooth ride and, if ours is anything to go by, very reliable.
Regards, 155 Man