GreyKnight Posted August 21, 2009 Report Share Posted August 21, 2009 Never heard of this before... See the pilot trying to get its fat arse off the ground at first. Quote Link to comment Share on other sites More sharing options...
Jediteo Posted August 21, 2009 Report Share Posted August 21, 2009 Looks like a Blackhawk made angry love to the submarine from Thunderball. Quote Link to comment Share on other sites More sharing options...
AndyJWest Posted August 21, 2009 Report Share Posted August 21, 2009 What's it supposed to do? Quote Link to comment Share on other sites More sharing options...
Jediteo Posted August 21, 2009 Report Share Posted August 21, 2009 It is a lot faster than normal helicopter, it has been tried before, but the stability has been a problem earlier. Didn't know they solved it. Quote Link to comment Share on other sites More sharing options...
Blairgowrie Posted August 21, 2009 Report Share Posted August 21, 2009 http://en.wikipedia.org/wiki/Piasecki_X-49 Quote Link to comment Share on other sites More sharing options...
Catalyst Posted August 21, 2009 Report Share Posted August 21, 2009 the whole point here is to defeat a condition called "retreating blade stall" that limits the top speed of a helicopter. A helicopter's top forward speed can't approach the speed at which the retreating side of the rotor would cancel each other out... thus making all the lift come from the advancing side of the rotor and roll the aircraft over. By making wings they introduce a new source of lift on both sides during fast forward flight. Quote Link to comment Share on other sites More sharing options...
GreyKnight Posted August 21, 2009 Author Report Share Posted August 21, 2009 Catalyst, I don't think this helo is being tested in order to defeat Retreating Blade Stall, as I doubt they can ever get around that. I think this prototype is testing to see if they can better performance from this Vectored Thrust Ducted Propeller. As a normal tail rotor uses up between 10% of a helo's power, just to stop it spinning around. So if they can use this new rotor for anti-torque AND an extra bit of thrust, along with the little wings, I guess these guys will be happier? But just seems... a bit daft to me. But I'd like to see how it pans out. Quote Link to comment Share on other sites More sharing options...
Tribunus Posted August 21, 2009 Report Share Posted August 21, 2009 The U.S. Army has been experiment with helicopters that had pusher propellers since the old Cheyenne back in the late 1960s. Quote Link to comment Share on other sites More sharing options...
DoubleTap Posted August 21, 2009 Report Share Posted August 21, 2009 BLUE THUNDER "This thing's nose-heavier than the Ayatollah!" X-49A "This thing's ass-heavier than Kim Kardashian!" Quote Link to comment Share on other sites More sharing options...
AndyJWest Posted August 21, 2009 Report Share Posted August 21, 2009 Seems to me that once you had enough forward speed, you could rely on the wings to provide lift, and stop the rotor entirely: no retreating blade stall (no retreating blade at all...). I'm not sure about the practicalities of this though, as the aerodynamic loads on the rotors would probably rip the forward facing one(s) off. Might be simpler to leave the rotor off altogether... Quote Link to comment Share on other sites More sharing options...
Rattler Posted August 21, 2009 Report Share Posted August 21, 2009 Seems to me that once you had enough forward speed, you could rely on the wings to provide lift, and stop the rotor entirely: no retreating blade stall (no retreating blade at all...). I'm not sure about the practicalities of this though, as the aerodynamic loads on the rotors would probably rip the forward facing one(s) off. Might be simpler to leave the rotor off altogether... You mean like this? http://www.aviastar.org/helicopters_eng/sik_x-wing.php "This then progressed into trials involving an X-wing in place of the main rotor. Using a compressed air system this airfoil could be blown to affect cyclic and collective pitch. The wing could be stopped in flight and Sikorsky believed the design had potential for future use as a high-speed 'convertiplane'. First flight took place on 2 December 1987, but after three further flights all funding was suspended and the S-72X1 was placed in storage at Edwards AFB. " Quote Link to comment Share on other sites More sharing options...
Cold_Gambler Posted August 21, 2009 Report Share Posted August 21, 2009 I'm sorry... I've stopped thinking about the helo... helly... heli--- those things with wings that whirl... UUUMMMMMPPPPPHHHHH! Niiiiiiiiiiiiiiiiiiice! Sweet mother is she fine. Quote Link to comment Share on other sites More sharing options...
Catalyst Posted August 21, 2009 Report Share Posted August 21, 2009 In light of recent threads, I propose Man-Law ###: Quote Link to comment Share on other sites More sharing options...
GreyKnight Posted August 21, 2009 Author Report Share Posted August 21, 2009 Man Law! Quote Link to comment Share on other sites More sharing options...
DoubleTap Posted August 21, 2009 Report Share Posted August 21, 2009 Vixens with red carpets. Oh, you are a dog alright! ~S!~ DT Quote Link to comment Share on other sites More sharing options...
Tribunus Posted August 22, 2009 Report Share Posted August 22, 2009 I'm sorry... I've stopped thinking about the helo... I agree completely. Quote Link to comment Share on other sites More sharing options...
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