But I just HAD to be the first person to choose the black helicopter :)

Bahhhh, ba-ba-ba-bahhhh, BA-BA-BA-BAHHHH, BA-BA-BA-BAHHHH, BAHHHH BA-BAHHHH BAHHHH bahh ba-bahh ba-bahhhh!

VAV

...the pink phallus-shaped one please......

Cocks away!!!

Mines the one with the Sicocksky branding on it....

I won't have it

... at something to know it's wrong.

Even if it was whisper quiet and could do 400 Knotts whilst sipping gently at a non-organic fuel, people still wouldn't use it simply because it just doesn't look right.

What would be so wrong with a good old fashioned jet turbine, mounted just below the rotor disc, with harrier-style nozzles to aid VTOL ?

Mine is the one with the oil stains.

To be really cool, you could use a turbojet, maybe?

Mine's the "airwolf" flying jacket.

There is a rotor-plane that can fly at mu=1, i.e trailing blade is stationary. The Carter-Copter (www.cartercopters.com) can take off vertically and land near vertically but fly at 450kts, so they claim. I want one NOW!

http://en.wikipedia.org/wiki/Kamov_Ka-50

still waiting for the model with turbo boost .

"Wasn't there a design where two lots of rotors intermeshed?"

Do you mean tandem rotors, one on each end and a body slung between? These are more common than you realise. They have feature in designs dating from the late 40s.

They're used in heavy lifting helos like the CH-47 Chinook (aka the Prince Willy taxi).

Jobs cos that's not a halo, they're supersonic rotor tips!

Well, at least for me, a pretty good explanation of the engineering problems. Useful reading.

For those who commented about the 'coolness' of jets, be they turbojets or turbofans compared with a turboprop, two main factors.

1. The pusher prop is driven off the main engine, i.e. it doesn't require an additional powerplant for the forward propulsion. This saves weight and hence fuel while allowing greating lift capacity and greater range.

2. Turboprops are more fuel efficient at these sort of speeds than either turbojets or turbofans. Fuel savings again giving rise to increased range and lift capacity.

As for comparisons with the V-22, hmm. It's taken over two decades effort by Boeing and the aircraft still isn't performing correctly. The V-22 is big, horrendously complicated and uses all manner of technology to perform certain tasks, e.g. auto-rotation, that have been solved perfectly well in the previous fifty years. The X-2, on the other hand, uses some very clever engineering *where it is needed* and in all other respects it is as simple as can be.

Now that's good engineering in my book.

Don't let 'em get you down MrPage, even if you did report on Sikorsky having developed a hyperdrive, I'm sure somebody would still be whinging about it one way or another.

Just wanted to add that I enjoyed reading this article, it was interesting, ta.

"Just out of interest, what would be news".

Well I supose fast trains and econmical cars would be news in the US.

Nice article however, so never mind funny comments.

can a coaxial rotorcraft autorotate? My CX2 can't autorotate, but it's admittedly a toy.

The control linkages for a real aircraft, with variable speed rotors, means each rotor needs separate collective and cyclic control linkages or acutators..is this all driven by electronic actuators? because mechanical linkages on two spinning shafts would be a nightmare. Toy coaxials only do the cyclic on the lower rotor and I haven't seen one that does collective on any rotor.

As far as transmission difficulties, this has a slightly less difficult design (tho the Osprey's power sharing transmission is unique not in implementation but dealing with the horsepower and being lightweight) but it's control implementation may provide some serious challenges. If it's all electronic it's easier but then you have absolutely no control if your electrical power is lost. Six of one, half-dozen of the other.

War is dangerous, and high performance aircraft for war use are even more so. Been that way forever, and isn;t going to change no matter what contractor is supplying hardware.

BTW, excellent article, LP!

Yes, you are thinking of the Kaman Huskie from the 50's-60's

http://www.h43-huskie.info/

(Mod., we need a propeller beanie or some other icon to denote mastery of trivial BS like antique aircraft/cars, etc)

Lewis, haven't you realised yet that The Reg comments sections are only EVER used by the glass-half-empty brigade?

Paris: I bet she's emptied enough glasses in her time.

In 1939 Flettner designed the first helicopters with counterrotating intermeshing rotors (the FL265 prototype). This was later developed into the FL282 Kolibri. See

http://www.fiddlersgreen.net/AC/aircraft/Flettner-282/flettner.php

for details

There was another design where there were two main rotor disks that intersected each other at a 90 degree angle. Each rotor hub was angled outboard, away from the fuselage, at a 45 degree angle.

It's name escapes me.

Mine's the one with the pilot wings drawn in with Crayola because it makes my passengers make funny faces.

Looks like a maintenance nightmare with all those enclosed and open shafts and numerous other vibration hazard points , all in all probably more trouble then it is really worth ! Might be a goer if the main blades are redesigned to take into account a concept that was solved by nature aeons ago though and only just rediscovered by man recently !

One should also not forget the current bulk of RAF aircraft are down and out due to either overtime on the frames , lack of decent spare parts or being flown by many pilots who can't even hit the broadside of a barn at even 100 paces , all thanks to Tony B Liar and his assorted boot licking take a bribe friends being too cheap to fund the real cost of his "Follow the DC Chimp's in your posterior adventures"

because she contra-rotates all the time..........

Journalism strikes again. Unless this is a direct quote. How can anything be four times less? Four times more, yes. A quarter, yes. But the illogical Americanism where more is less. Ouch!

Mine is the one with the lexicon in the pocket.

Grumpy Old Git

I thought the main reason heli's are not in common use in urban environments is more to do with the cost of running and maintaining them. That and the rotors tend to be a safety concern (something the X2 doesn't really address) needing quite a large safety exclusion zone for takeoff and landing. I would think the noise levels would be only a minor issue by comparison.