Hi All,
I may be a bit off base here so bear with me. Could you not use a rate of climb check in this case? I'm refering to the original posters situation not to the case of taking off from an oil rig etc.
If you can't account for the wind and it's effects on the machine then why not move through the air at a given rate and at a given power setting and altitude and see how fast the machine climbs. We use this often on the Astar when questioning the power check results. Where the power check tells you if the engine is producing enough torque on the drive shaft for given circumstances, the rate of climb tells you how fast the aircraft should climb at MCP and 55kts at a given AUM. In this case Devil 49's pilot could see how fast the ship climbed at a given "wind" speed of 55kts. As I said I know the 350 series has this chart availablein the RFM but I don't know if it exists in many others.
Just a thought
Max