Airbus just patented what could be the world's fastest helicopter
 

I suppose we all knew that the X3 design would be used somewhere.

Airbus patented fastest helicopter - Business Insider

No they havent'
 

coz that ain't a helicopter

lift/thrust compound rotorcraft maybe..

DM

It's not a new idea; it's been previously referred to as a "compound helicopter" and the concept was extensively explored by Lockheed with the XH51A-compound* and subsequent AH56 Cheyenne programme*.

The general idea is to have the stub wings develop sufficient lift that in cruising flight the rotor runs at zero pitch to eliminate the advancing blade problem, while still acting as the primary pitch/roll control with cyclic pitch.

Bell did something similar with their experimental model 533, and MacDuck also did the McDonnell XV-1. Oh and of course there was the Fairey Rotordyne which went a stage further, being a compound helicopter that was also an autogyro depending on how fast it was flying at the time.

So the basic concept isn't novel - we have to assume that AIrbus have managed to find some extra novel features to justify the Patent.

PDR

* One of the Lockheed model 286s demonstrators they built to develop the rigid rotor concept for the Army Observation Helicopter competition, with a single stub wing carrying a 3,000lb thrust turbojet. It is alleged that it was so fast that the plexiglass canopy would squash inwards when flown "with gusto".

** The AH56 had a rigid rotor and two tail rotors - one tail rotor was coaxial with the tail boom and provided thrust. It had variable pitch and so could provide powerful deceleration as well as acceleration.

Based on the video, they might first want to get the rotor turning the correct direction

Sad jokes spring to mind. Ones better keep quiet.

Based on that patent application, it appears that the original X3, with engine mounted props facing forward, adjacent to the ingress/exit of the cabin, has been changed in the patent sketch to be pusher props with props well behind ingress/egress to the cabin.


The video chooses "next fastest" as Chinook ... uh, CH-53E is pretty fast its own self with an advertised 170 know/196 mph speed ... and I think it has flown faster than that. :cool: I guess they ignored Sikorsky's most recent 200 kts plus design (X-2) that is moving head into the S-97? :confused:


Anyway, looking forward to seeing that one fly to see what it adds to the state of the art.

You'd think Airbus could at least afford decent CGI instead of something that looks like the CEO's nephew cobbled together in Sketchup.

Just remember the X3 did make 250kts as a full size Dauphine adapted so we knew they would move either to shrouded ala fenestron or rearward populsion. The X3 flew a world tour?

OBVIOUSLY this was not released by AH. Apparently it was not even the CEO's nephew but some youtube nutter calling himself PatentYogi.

I cant see how this is "new" concept and patent worthy as its just a rehashed British design TheFairy Rotodyne... they tried the props both ways aswell....

The Airbus Helicopters US patent noted in the article is based on a US application filed in July 2013, which was the month after X3's first flight, and an EU application (12400032) filed in July 2012. The AH patent in question (9,321,526) was granted by the US patent office, but the 18 claims it contains describe a compound helicopter with a specific arrangement of features that is novel, rather than the general concept of a compound helicopter. Eurocopter has several patents covering the X3 concept going back almost a decade.

Airwolf was faster (M1.3)

Fats

Airbus Helicopters to reveal X3 successor plan at ILA Berlin Airshow


https://www.flightglobal.com/news/ar...r-plan-425745/

Per the abstract on the first page of the patent linked to from OldblokeTH53's article, the difference here is that the aircraft is using the same engines to mechanically drive both the rotor and the propulsors, in a similar vein to the Piasecki 16H/VTDP, Cheyenne and X2/S-97/SB>1. The XH-51A (and Bell 533, NH-3A, S-72, XH-59A & YUH-2, etc.) used auxilliary engines which imposed a weight/fuel burn penalty, while the Rotordyne (and SO.1310, XV-1 & XV-9, etc.) used tip jets, with the associated acoustic issues.

Still surprised, though, that the new patent shows unshrouded props mounted at head height. It's already hard enough trying to keep VIP pax safe on a clear day at Battersea, let alone keeping roughnecks safe on a rig in a squall while five of MT-Propeller's best are trying to re-enact a scene from Raiders. (Unless the plan is to de-clutch the props on deck?)

Meanwhile, Flight reports that Airbus Helicopters will reveal its X³ successor at next week’s ILA Berlin air show, in terms of a concept developed under the EU-funded Clean Sky 2 effort.

I/C

Good point - I'd overlooked that.

True, but (as I alluded to previously) only when hovering or transitioning. In transient flight the rotor autorotated, so the penalty was the small additional weight of a fuel lifting pump & valves, pipes in the blades and the tip air-kerosene rockets themselves (which were tiny) plus some additional rotor drag from the non-operating tip motors. I would guess that this would be substantially less weight than the transmission systems for the single-engine alternative. The compressed air supply to the tip rockets was tapped from the compressors of the turboprop "thrust" motors, so what constitutes an "auxiliary engine" is a matter of definitions.

But as you say, the tip-rocket noise at the hover was completely unacceptable for something that was hoped to find a niche in ferrying between inner-city locations and airport hubs, and that's what killed it!

Of course the Fairey Gyrodyne (the original concept demonstrator) used a single engine to power both the rotor and the "thrust" propeller, while the Jet Gyrodyne that followed it used a single engine to drive the twin thrust propellers and the compressors (three Merlin superchargers, I believe!) that supplied the air feed to the tip-mounted air/kerosene rocket motors, so arguably both of these also used a single engine rather than a separate auxiliary engine. I believe the jet gyrodyne also used differential pitch on the thrust propellers for yaw control, but I could be wrong on that.

PDR

I think what is most humorous about all this "world's fastest" bluster is that neither the X2, nor X3 were ever certified by the FAI...so while both Airbus and Sikorsky turn blue in the face claiming to have the "worlds fastest helicopters", the true record holder is still trusty old G-LYNX

The more practical issue facing the X2 and X3 concepts in the commercial market is are customers willing to pay the higher cost for the increased performance? I think the answer is probably not for most customers. What they would be more interested in is a helicopter that is more fuel efficient, lower maintenance, and more comfortable for its passengers/crew.

ILA Berlin press release
 

I attended ILA in the week and received press release from AH

'Berlin, 1 June 2016 – Airbus Helicopters earlier this year passed an important milestone in the development of the high-speed, compound helicopter demonstrator currently being built as part of the Clean Sky 2 European research programme. A mockup of the breakthrough airframe design has just undergone windtunnel testing in an Airbus facility. The tests proved the viability of the chosen design in terms of efficiency, sustainability and performance, paving the way for a preliminary design review expected end of 2016. Meanwhile, the overall project has passed its first official milestone involving all core partners by reaching the end of its pre-design phase'

Artists concept of the concept in corporate, offshore and EMS config,

cheers



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Can I ask a basic question as someone who doesn't know too much about helicopter technology please.

I understand why a conventional helicopter requires a tail rotor - to counteract the natural tendency of the body of the helicopter to try and rotate in oppositional/sympathy with the overhead rotors. I can understand that having two outboard propellors could achieve the same function of a single tail rotor.

But what would happen of one of the two outboard propellers suffered a fault and stopped turning. It would seem to me this could lead to some difficulty with counteracting the natural turning action of the helicopter body as described above.

I'd be grateful for a simple answer using layman's language. Thank you.

Difficulty would probably less if you lose one of two side rotors, than one of one tail rotor, don't you think?