The S76C+ seems to have a problem passing the automatic power assurance when it's operated in hot climates (above 25-30 degrees). The airframe and engine manufacturers both say that the definitive PA is the manually recorded one, using the FM graphs. There are some differences between the inputs from the engines to the DDR and the cockpit gauges and this can be the difference between a fail and a pass. When we were operating them in hot conditions and having a lot of problems with PA, Sikorsky tried to blame Turbomeca and said that they were supplying the better specification engines to Eurocopter for the EC155, whilst Turbomeca claimed that it was the fault of Sikorsky because the air intake system was not properly matched to the 2S1 engines. Maybe it's a bit of both!