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Old 16th Jun 2009, 16:57
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Medhawkdriver_25
 
Join Date: Jun 2009
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Excellent!

Thank you gentlemen (and ladies?) for your responses. This is great stuff!

The aircraft I personally am dealing with IS indeed an S76...A model. I was intrigued to read that an S76 rotor system will develop more lift per shp at a hover at 100%Nr. I am relatively new to the "76" and my training was far from comprehensive, which is why I am left posing questions like this one. One point that WAS brought up in training, though, was that the reason for reducing Nr to 96% after establishing a positive rate of climb (Continued takeoff after engine failure) was that the rotor system was more efficient in a climb at 96%. That being said, perhaps lower is actually better? On the other hand, that 96% is more efficient in a climb may be based on the assumption that by THAT point in the procedure there is a significant amount of translational lift helping the situation?

In the lift equation, Lift becomes a function of Velocity squared, right? So, theoretically, higher revs = more lift. I do understand that there is a point of diminishing returns which plays into what Mast Bumper is saying. Maybe it IS pointless to discuss unless we know the airfoil. Mr. Bumper, can you divulge your source on the main rotor aerodynamic properties of the S76? Does anyone know why the recommended Nr of an S76A++ is 107%, yet the A model is lower?

Thoughts?
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