The tail rotor provides thrust and the wings provide lift unloading the main rotor allowing for 50% faster flight, twice the range, less vibration and more maneuverability according to the Piasecki website.
@FJones9508 As they go faster, they have to slow down the main rotor because the advancing blade would go over mach 1. This reduces the lift from the rotor, so the wings are needed. Retreating blade stall is also an issue, but I think the advancing blade going over the sound barrier is more of an issue because it can cause violent vibrations.
the idea is to shift lift from the rotor to the wing and thrust from the rotor to the ducted propeller, that way the rotor blades can operate at lower pitch, delaying the stall
Very strange!! It looks tail-heavy on takeoff and landing, but seems to fly pretty well. I'm guessing thrust vectoring to the left couter-acts the torque, like a normal tail rotor...
I believe the point of this is to eliminate the tail rotor and get more speed - 2 for 1 deal. They haven't come close yet to the potential of the system. I believe the AH-56 had a tail rotor along with it's pusher prop.
They hope to get over 200kt once the clean the helicopter to reduce drag - make the gear retract and put a fairing round the rotor hub. The vectored thrust ducted propeller does the job of the tailrotor using "visor" vanes that defect the propeller thrust
That was the original idea - and why the X-49A is a modifired Navy SH-60F prototype - they needed the thruster to help pull the mine countermeasures sled through the water. But the Navy seems to have lost interest and now the Army has taken the lead - looking at it to improve the performance of the Black Hawk...maybe
Ok, this concept is good, but I think that they are working with the wrong airframe. The vectored-thrust ducted propeller (VTDP) in a helicopter is a nice idea. But if you look at the test, when the Speedhawk is at low speeds looks like its tail gives too much weight. So I say that with other mainframe it could be better balanced to the VTDP.
My first thought after viewing this was.."whats the point" my second was "the CG looks too far aft". My third was I get it, extra forward speed but wondering if the limitations posed by retreating blade stall still apply? I think the answer is yes. I wonder how well it flys backwards.
Look up the AH-56 Cheyenne. It had wings and a pusher prop and moved out at 244mph!!! that was in 1967!!
The tail rotor provides thrust and the wings provide lift unloading the main rotor allowing for 50% faster flight, twice the range, less vibration and more maneuverability according to the Piasecki website.
@FJones9508 As they go faster, they have to slow down the main rotor because the advancing blade would go over mach 1. This reduces the lift from the rotor, so the wings are needed. Retreating blade stall is also an issue, but I think the advancing blade going over the sound barrier is more of an issue because it can cause violent vibrations.
Awesome! I just love it!
if you look close, you'll notice that it was the first takeoff. The pilot was probably just trying to get used to a different flight configuration.
the idea is to shift lift from the rotor to the wing and thrust from the rotor to the ducted propeller, that way the rotor blades can operate at lower pitch, delaying the stall
@FJones9508 yes, designed to compensate lift as blades start stalling
177 knots is 203.6 MPH. Not fast today, but up there for the time.
Very strange!! It looks tail-heavy on takeoff and landing, but seems to fly pretty well. I'm guessing thrust vectoring to the left couter-acts the torque, like a normal tail rotor...
interesting, thanks for posting.
I believe the point of this is to eliminate the tail rotor and get more speed - 2 for 1 deal. They haven't come close yet to the potential of the system. I believe the AH-56 had a tail rotor along with it's pusher prop.
@thekaizer666 they've done that in tests. I believe a turbofan engine was put on a UH-1 and it flew pretty dang fast.
The wing and thruster offload the rotor, so it can operate at lower angle of attack, but retreating-blade stall still limits the speed to around 200kt
yes its at the boeing flight facility there.
interesting concept.
They hope to get over 200kt once the clean the helicopter to reduce drag - make the gear retract and put a fairing round the rotor hub. The vectored thrust ducted propeller does the job of the tailrotor using "visor" vanes that defect the propeller thrust
That was the original idea - and why the X-49A is a modifired Navy SH-60F prototype - they needed the thruster to help pull the mine countermeasures sled through the water. But the Navy seems to have lost interest and now the Army has taken the lead - looking at it to improve the performance of the Black Hawk...maybe
the wings unload the rotor at high speed, stops the retreating rotor blade from stalling, which is what limits the speed of a helicopter
Ok, this concept is good, but I think that they are working with the wrong airframe. The vectored-thrust ducted propeller (VTDP) in a helicopter is a nice idea. But if you look at the test, when the Speedhawk is at low speeds looks like its tail gives too much weight. So I say that with other mainframe it could be better balanced to the VTDP.
My first thought after viewing this was.."whats the point" my second was "the CG looks too far aft". My third was I get it, extra forward speed but wondering if the limitations posed by retreating blade stall still apply? I think the answer is yes. I wonder how well it flys backwards.