Tony Posted October 26, 2015 Report Share Posted October 26, 2015 How can this hover upside down Quote Link to comment Share on other sites More sharing options...
SMARTLY Posted October 26, 2015 Report Share Posted October 26, 2015 Awesome pilot and a pretty capable 'copter. To do that in the confined space of a forest is pretty cool. Quote Link to comment Share on other sites More sharing options...
Tony Posted October 26, 2015 Author Report Share Posted October 26, 2015 I must say the initial move made me jump...... But how can it hover upside down when the thrust should push it down? Quote Link to comment Share on other sites More sharing options...
liner33 Posted October 26, 2015 Report Share Posted October 26, 2015 because helicopter blades generate lift not thrust Quote Link to comment Share on other sites More sharing options...
Tony Posted October 26, 2015 Author Report Share Posted October 26, 2015 Yeah but lift upward is resisting gravity, turn that around it should smash into the ground. Quote Link to comment Share on other sites More sharing options...
liner33 Posted October 26, 2015 Report Share Posted October 26, 2015 Eh? Planes fly upside down , how do you think that works ? Quote Link to comment Share on other sites More sharing options...
Tony Posted October 26, 2015 Author Report Share Posted October 26, 2015 Rudders?..... Quote Link to comment Share on other sites More sharing options...
andyelcomb Posted October 26, 2015 Report Share Posted October 26, 2015 I would have thought asking how it seems to hover vertically is more relevant than inverted. It makes my efforts with a relatively newly acquired quadcopter just so pathetic. The control shown in those 3D helicopter clips is just staggering. Quote Link to comment Share on other sites More sharing options...
Tango Posted October 26, 2015 Report Share Posted October 26, 2015 You reverse the pitch on the rotor blades. Model helicopters can only fly upside down because their collective pitch control allows the rotors to be negatively pitched. That is, to direct air flow "up" relative to the fuselage instead of "down". Wouldn't want to attempt it on a full size though! Quote Link to comment Share on other sites More sharing options...
SHAHZ Posted October 26, 2015 Report Share Posted October 26, 2015 Bloomin ek! That is crazy!! Mans got some skills ! Quote Link to comment Share on other sites More sharing options...
Tony Posted October 27, 2015 Author Report Share Posted October 27, 2015 You reverse the pitch on the rotor blades. Model helicopters can only fly upside down because their collective pitch control allows the rotors to be negatively pitched. That is, to direct air flow "up" relative to the fuselage instead of "down". Wouldn't want to attempt it on a full size though! Ah so i was kind of right to be confused..... I trust this changing of the pitch to negative isn't possible in real HC's Quote Link to comment Share on other sites More sharing options...
adam_r Posted October 27, 2015 Report Share Posted October 27, 2015 I would assume it is. But not quite to the extent that RC helicopters do. Also Dont forget an rc helicopter has an amazing power to weight ratio.( very light and powerful) whilst a full size chopper is pretty dam heavy and does not have tge same power to weight ratio. I know redbull have a stunt helicopter that flys upside down... Quote Link to comment Share on other sites More sharing options...
SMARTLY Posted October 27, 2015 Report Share Posted October 27, 2015 This one: https://www.youtube.com/watch?v=uYbx5H5e9Es Quote Link to comment Share on other sites More sharing options...
liner33 Posted October 27, 2015 Report Share Posted October 27, 2015 Used to watch these guys in action when I was at Odiham Impressive Quote Link to comment Share on other sites More sharing options...
Tango Posted October 27, 2015 Report Share Posted October 27, 2015 I would assume it is. But not quite to the extent that RC helicopters do. Also Dont forget an rc helicopter has an amazing power to weight ratio.( very light and powerful) whilst a full size chopper is pretty dam heavy and does not have tge same power to weight ratio. I know redbull have a stunt helicopter that flys upside down... Doesn't really fly inverted though, in fact you can see he loses height during the rolls when he is momentarily inverted. The power to weight is one obstacle, and the other is the blade clearance if they were put in negative pitch whilst inverted. The blades can be put into negative which is necessary in descent mode with cyclic down so the airflow maintains rpm during autorotation in the event of engine failure, in effect providing a winged flywheel that stores energy until the pilot raises the collective (pitch positive) to flare for a landing to ground level. Quote Link to comment Share on other sites More sharing options...
Tony Posted October 28, 2015 Author Report Share Posted October 28, 2015 Used to watch these guys in action when I was at Odiham Impressive Impressive indeed...... What i really like is the sound, makes me want to shout "Vietnam is was there"....... Quote Link to comment Share on other sites More sharing options...
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