X2 triplex supercopter gets tail-drive hooked up US helicopter firm Sikorsky has announced successful ground testing of its "X2" twin-rotor, tail-prop high speed helicopter prototype with the tail propulsor fitted and working. The firm says the X2 is on track to achieve 250-knot speeds this year - beating normal helicopters by two thirds again. Sikorsky art of the X2 …
Looking at that illustration of the X2, how does it land? It looks like wheels at (roughly) the midpoint, but it's not going to balance on those.
Usually there'd be a tail-wheel in this case, but there's none on the image, so the only other conclusion is that the back-end will rest on the edge of that fin. Seems odd, if nothing else...
Indeed, why waste all that time on the tail propeller when they could just stuff a large firework up its arse?
Also, will the Americans give their 'allies' the radio controls for these helicopters to help reduce the incidence of friendly fire? In fact, even better, why put an American pilot and everyone else at risk when they could just launch them as UAVs and program them to fly into control range of their allies' forces on the ground?
I think the whole point of the V22, regardless of how well it performs or how controversial it is, was to be able to carry at least a platoon of soldiers and their equipment at high speeds to achieve rapid deployment combat initiatives. From the picture at least, I dont see where they will fit 10-12 heavily armed paratroopers. Even it it were to be upscaled, the rear prop is going to require some sort of a drive shaft if you nix a helper engine. Either way thats going to be a space problem, unless they went electric with the rear engine. It looks like it could make a nice attack helicopter though and could escort the more ungainly V22 around the battle field. But it's got its work cut out for it playing head to head against the Cobra, the Apache, and even the A-10II.
We already have helicopters with rotors that power-fold after landing, so surely a better solution would be a conventional plane with a folding and retracting double rotor (ala Kamov) in the cabin roof? Unfold the rotor for take-off, then use normal engines and rotor lift until forward speed reaches the point where wing lift can support the plane, then the rotor can be stopped and folded away and conventional flight pursued. If a vertical landing is required or you want to hover, the forward speed can be lowered to that at which the rotor can be unfolded and powered up, then the speed can be reduced until rotor lift is supporting the plane again. Such a setup would give the advantage of allowing conventional or vertical take-offs and landings. And it would have really cool Tranformer connotations!
@Matt Bryant: In-flight transitions such as the ones you describe are incredibly difficult both from an engineering and aerodynamic POV. Think about the aerodynamics of the craft as the rotors are folding/unfolding while traveling forward at high speed... It's slightly harder than trying to do origami while standing in the back seat of a convertible sports car with the top down while driving at 150 mph...
If you look at previous examples, the transitions are always the hardest problem: the V22, the Harrier (which "merely" orients its ducts), the STOVL variant of the F35. Even the swing-wings on the old Tornado turned out to be much harder than expected to engineer.
When do we get a reboot of the Airwolf franchise with one of these in the lead role?
@Anonymous Coward Posted Tuesday 3rd February 2009 13:52 GMT
"the X2 is on track to achieve 250-knot speeds this year - beating normal helicopters by two thirds again"
I point out the word "NORMAL" there. What dont you understand about it?
/Black Heli cause well.....it just fits
two blades on top of each other like that, going in opposite directions, won't that make it vibrate, as it wont be symmetrical loading. I know that is a common design, but at high speed the effect would be amplified.
a synchrocopters intermeshing blades would make it symmetrical, stable and best of all looks really evil. look up the karman k-max
Haven't time to do exhaustive research on the issue, but a quick Google turned up the KA-50
http://www.youtube.com/watch?v=LT3IFVAE7CU
http://en.wikipedia.org/wiki/Kamov_Ka-50
I grant that the KA-50 is still in the 150kt category though; it doesn't have a pusher prop (or Airwolf style jet assistance!)
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2025
