scorpiomikey Posted July 11, 2013 Share Posted July 11, 2013 So i was browsing around today, and came across the "New worlds fastest helicopter" The Eurocopter X3 (X-cubed) But im trying to decide if it can actually be called a helicopter or not. What are your thoughts? Image courtesy of GizMag Link to comment Share on other sites More sharing options...
Martian Posted July 11, 2013 Share Posted July 11, 2013 Yes definitely. Lift is still generated by the rotors. I suspect that both props turn in the same direction to counteract torque whilst adding to thrust at the same time. Martin Link to comment Share on other sites More sharing options...
scorpiomikey Posted July 11, 2013 Author Share Posted July 11, 2013 (edited) Still feel theyre cheating by getting thrust from the outrigger props. Edited July 11, 2013 by scorpiomikey Link to comment Share on other sites More sharing options...
stevehnz Posted July 11, 2013 Share Posted July 11, 2013 Can it stop & hover, go sideways & backwards? If so then its a helicopter to my mind, if not maybe a gyrocopter. Steve. Link to comment Share on other sites More sharing options...
rotorheadtx Posted July 12, 2013 Share Posted July 12, 2013 I would call it a compound helicopter, an animal in a category unto itself. Lumps in with the Cheyenne, Sikorsky X2, and Piasecki's fan-tails. The kicker is the fact that it's down to a matter of semantics; the FAI does not have separate classes under the field of rotorcraft, so Eurocopter can claim they're the fastest. Read the blurb in the pdf link, and there is an amusing argument made that the the X3 doesn't count as a rotorcraft by FAI's own rules if it's main lift at speed is from the wings. But it's from the Royal Aeronautical Society, so of course Lynx still rules!! http://aerosociety.com/Assets/Docs/Publications/SpecialistPapers/Definition_of_a_Rotorcraft.pdf Link to comment Share on other sites More sharing options...
rotorheadtx Posted July 12, 2013 Share Posted July 12, 2013 (edited) It also works well as a steward(ess) slicer and passenger processor.... "Please exit the doors, turn, and move to the REAR of the aircraft" Edited July 12, 2013 by rotorheadtx Link to comment Share on other sites More sharing options...
Les Moore Posted July 12, 2013 Share Posted July 12, 2013 Call it what you will...its splendid...wished I had one. Link to comment Share on other sites More sharing options...
Rick Brown Posted July 12, 2013 Share Posted July 12, 2013 Hmm, isn't the limiting factor of forward speed, of a chopper, dictated by the maximum speed at the tip of the rotor blade (or sumat like that, sniff)? I can't see what this is trying to achieve? Does this slightly improve speed by being able to slow the rotor a little maybe? It seems to have all the faults of both fixed wing and helicopters, oh, and damn dangerous to work round whilst on the pan. Also, I wouldn't want to ditch in one.. Don't get me started........ Weirdos Whiff of "Cos we can" Maybe it's just me. You can tell I read a "How things work" magazine years ago. Rick.. Link to comment Share on other sites More sharing options...
Nigel Heath Posted July 12, 2013 Share Posted July 12, 2013 This is an attractive looking machine, I don't suppose there is a kit of it out there yet? 1 Link to comment Share on other sites More sharing options...
Pete in Lincs Posted July 12, 2013 Share Posted July 12, 2013 Oh those naughty Frenchies! Fancy them not sticking to the rules. Bet it can't, Carry troops, detect submarines, land on the back of a heaving ship etc etc.....Going to sneeze.... LYNX! Pete 1 Link to comment Share on other sites More sharing options...
andy wood Posted July 12, 2013 Share Posted July 12, 2013 This is an attractive looking machine, I don't suppose there is a kit of it out there yet? Looks like it is asked on a Dauphin fuselage, so it could be an easy scratch conversion. Link to comment Share on other sites More sharing options...
Nigel Heath Posted July 12, 2013 Share Posted July 12, 2013 Not sure I would use the word easy, it looks like it would be a major carve up to me, could be a good project though. http://modelingmadness.com/review/mod/michaelsdauphin.htm Link to comment Share on other sites More sharing options...
Nigel Heath Posted July 12, 2013 Share Posted July 12, 2013 (edited) From this article it sounds like a hybrid of several machines:http://australianaviation.com.au/2010/09/eurocopter-unveils-x3-helicopter-hybrid/ Edited July 12, 2013 by Nigel Heath Link to comment Share on other sites More sharing options...
Nigel Heath Posted July 12, 2013 Share Posted July 12, 2013 Including this one:https://en.wikipedia.org/wiki/Eurocopter_EC145 Although the tail looks much bigger on the X3 to me. Link to comment Share on other sites More sharing options...
Rick Brown Posted July 12, 2013 Share Posted July 12, 2013 This is an attractive looking machine, I don't suppose there is a kit of it out there yet? Got one on back order from Hannants. It certainly looks interesting and it's nice to see a company still doing major R+D and pushing technology in these desperate times. Good look to them and I'm sure something useful will come out of this. Rick. Link to comment Share on other sites More sharing options...
Nigel Heath Posted July 12, 2013 Share Posted July 12, 2013 (edited) Do you mean a Eurocopter EC145? I can't see anything else at Hannants that ties in with this. Edited July 12, 2013 by Nigel Heath Link to comment Share on other sites More sharing options...
pigsty Posted July 12, 2013 Share Posted July 12, 2013 Hmm, isn't the limiting factor of forward speed, of a chopper, dictated by the maximum speed at the tip of the rotor blade (or sumat like that, sniff)? I can't see what this is trying to achieve? Does this slightly improve speed by being able to slow the rotor a little maybe?Yes indeed. This isn't a finished design, it's a technology demonstrator, intended to be the first step towards a high-speed helicopter. The basic idea is that the rotor is used mainly for lift and thrust at low speeds, while at high speeds the propellers and stub wings take over. The problem of the rotor blades going supersonic (especially the advancing one) is solved by slowing it down as the wings take over.I suspect that both props turn in the same direction to counteract torque whilst adding to thrust at the same time.In fact, one turns faster than the other.Oh ye of short memories! This isn't the first attempt. Sikorksy had the same idea about 35 years ago, although their idea was that the rotor would stop completely at a high enough speed and provide lift solely through the airflow going past it. This idea foundered on three problems: getting the rotor to stop while maintaining control; having to use an aerofoil that provided the same amount of lift no matter what way it was facing. This was partly addressed by using boundary-layer control to adjust the lift the rotor blades generated, with a system of valves to direct the blown air along the correct edge of each blade, depending which side of the aircraft it was on. Fiendishly complicated; and cost! A slower rotor, as opposed to a completely stationary one, seems likely to work better.Then of course there was the Rotodyne, although it was fundamentally different in that the rotor was never intended to provide thrust, making it a compound autogyro rather than a helicopter. The AH-56 was similar in concept to the X3 but I don't believe they ever planned to slow the rotor, only to transfer lift from it to the wings as speed increased. This would have limited its speed to below what Eurocopter is hoping to achieve. You may be wondering, why the bother when we have tilt-rotors? To which the answer must be, I suppose, a combination: it has a smaller ground footprint; you never have a risk of a vast propeller refusing to return to the upright position; it can auto-rotate; and it might offer some competition, so anyone wanting high speeds and VTOL doesn't have to buy a tilt-rotor. 2 Link to comment Share on other sites More sharing options...
andy wood Posted July 12, 2013 Share Posted July 12, 2013 Not sure I would use the word easy, it looks like it would be a major carve up to me, could be a good project though. http://modelingmadness.com/review/mod/michaelsdauphin.htm Nah, piece of willie water. Link to comment Share on other sites More sharing options...
hwallen1410 Posted July 12, 2013 Share Posted July 12, 2013 (edited) Oh those naughty Frenchies! Fancy them not sticking to the rules. Bet it can't, Carry troops, detect submarines, land on the back of a heaving ship etc etc.....Going to sneeze.... LYNX! Pete Those of us who work at Donauwörth, Ottobrunn, Kassel, Albacete and Madrid might not agree with that........ Edited July 12, 2013 by hwallen1410 Link to comment Share on other sites More sharing options...
Rick Brown Posted July 12, 2013 Share Posted July 12, 2013 Gawd I'm glad I come here, there's soooo many very intelligent people like yourself Pigsty that make me feel very dim! Thanks for clearing a few things up, cheers chap. Rick Link to comment Share on other sites More sharing options...
cardiff guy Posted July 12, 2013 Share Posted July 12, 2013 hmmmm looks like someone has re invented the fairy rotodyne just smaller. Glenn. Link to comment Share on other sites More sharing options...
rich2010 Posted July 16, 2013 Share Posted July 16, 2013 If I remember rightly, a helicopter's forward speed is limited by what's called retreating blade stall. When the forward speed of the helicopter is too great the retreating blade's relative speed is too low to provide lift. I believe the helicopter irrecoverably flips over. Not good. Advancing blades also 'have issue' with high speeds, but like our correspondent above states, once the stub wings provide enough lift, the rotor could be disengaged or made to provide no lift. Not sure that's possible, but my name isn't Sikorsky. Someone like FAAWAFU, being a pilot, might be able to provide a better explanation. Link to comment Share on other sites More sharing options...
pigsty Posted July 17, 2013 Share Posted July 17, 2013 When the forward speed of the helicopter is too great the retreating blade's relative speed is too low to provide lift.That is indeed the problem. It got worse with the X-rotor idea, because the stage where the retreating blade was providing least lift was also the stage where it had to be made slower in order to allow it to stop altogether. One solution was Sikorsky's S-69, which had co-axial rotors and got most of its lift from the advancing blades without any asymmetry problems. Thrust came from two small turbojets. The idea, er, stalled, not because of any fundamental problem with it but because the test airframe had other problems and the US lost interest in paying for them to be fixed.Funny how every few years someone tries out another way of overcoming the helicopter's limitations, and then the helicopter just carries on. The tilt-rotor seems to be a successful approach; time will have to tell when it comes to the X3. Link to comment Share on other sites More sharing options...
Michaelvk Posted July 17, 2013 Share Posted July 17, 2013 looks like an overcomplicated maintenance nightmare to me.. Link to comment Share on other sites More sharing options...
Lynx7 Posted August 24, 2013 Share Posted August 24, 2013 (edited) Its strictly a 'Compound' when it comes to the FAI. The record is still held by a Lynx. I.e its thrust being derived purely from the main rotor system. As has been suggested, the X3 derives its thrust by a combination of main rotor and propellers. If it were not the case, the certificate that G-LYNX would be on the wall of the Chief Test Pilot in Marseille. It aint, its still in Dons old office in Somerset......... Nice idea (but have you seen the vibe it has in low speed and the hover???) An exercise in 'look at what we can do'. Do us a favour and sort the Super Puma out first please... Edited August 24, 2013 by Lynx7 Link to comment Share on other sites More sharing options...
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