PPRuNe Forums - View Single Post - Helicopter crashes at Lumberton airport
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Old 17th Sep 2017, 05:00
  #48 (permalink)  
Old Farang
Join Date: May 2016
Location: Bangkok
Posts: 107
Originally Posted by [email protected] View Post
Nige, I think there are so many variations of transmission across helos that might be difficult - I am also transferring what I know from turbine aircraft across to piston but there may be differences - eg on the R22 with that weird squirrel cage and drive belt arrangement, I have no idea what drag there might be through that system.
Crab, you appear to be one of the few that know what they are writing about(also double bogey). Please look up the definition of both ''friction" and "drag". If there is any of either when ANY type of freewheel device is activated, then there is a fault with the device.

I do not know about turbines, but with the R22 the squirrel cage sprag clutch most definitely does not have any contact when disengaged. No contact, no friction, no drag. I doubt that any Helicopter would be certified if there was not an approved freewheel device that completely disconnects the power input source from the rotor system.

The poster that has concerns about the MR over speeding when in auto rotation has either not been trained correctly, or has never been in auto rotation! Cheers.

edited to add the following: http://www.rotorandwing.com/2010/02/...a-sprag-thing/
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