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New Eurocopter

I don't know whether to laugh or cry... :isadizzy:

As I posted over at HC, I'm putting my money on Sikorsky to 'Win'. :icon_lol:


Here's video of the...thing:

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Lionheart said:
... loves the Rotordyne! What a ship...
Click to expand...
+1
But a totally different bird from this Eurocopter!
Presumably the project was killed by the nest of Soviet spies running the British MOD in 1959...there can be no other explanation, really. :icon_eek:
Brilliant concept...Tip jet autogyro (and hence fail-safe performance), no torque rotor, capable of safe single engine performance. High cruise speed, docile handling.
Really, someone should build one with 21st-century control systems and materials.
 
Lionheart said:
Thanks for the heads up RayRey.

Interesting looking helo.

<-- loves the Rotordyne! What a ship...
Click to expand...

...but VERY noisy apparently with its jet tipped blades ....and no doubt very uneconomical to operate commercially even in the early 60s
 
BUT they successfully tested a silenced tip jet in the death throes of the project.
Not sure about the economics - I know there was an issue with seals on the compressed air feed into the rotor, though.
 
I must say this is an interesting project.. Albeit I imagine it is going to be a maitenance nightmare, and not very cost efficient for the operator. Sikorsky had a similar aircraft powered by turbofan engines in the 70's/80's (S-72 http://www.helis.com/70s/h_s72.php ). That Eurocopter looks very stylish in comparison.. Definately like it a lot better than Sikorsky's X-2 though. At least with the X3 you can carry people and do stuff. Just like I said I do not think it will be economical. It has essentially combined a single rotor helicopter disc with some type of system to reduce main rotor RPM at high speeds.. And a driveshaft system that takes power off the MGB to power the outter props. It just seems like when they pulled it up into a hover that it has quite a bit of vibrations in the wings, and in the tail cone section of the bird.. Maybe mostly caused by down-wash from the main rotor, but any type of frame vibes like that will decrease the lifetime of the frame substantially. Would be interested as well to see how the rotor RPM changes the vibe signatures.. Cause on the H-60 as the rotors spin up there are some awful vibrations that occur at RPM's other than the rated 98-103% NR. So they would need some kind of system to account for that as well.
 
Sikorsky's X2 is a test vehicle at this point, it initially was never intended to be put into production, only to test the feasibility of such a design. :salute:
Obviously that design is working well so it may developed into a passenger carrying version.

The X2's rear fan is inline.
Combined with counter-rotating props for stability, if you lose that rear fan, you slow down.

Now look at the X3 whose engines are at the end of a couple polar moment arms on those wings.
I just have to wonder how stable that is going to be if you suddenly lose an engine at high speed combined with the torque from the main rotor.
That dead engine is going to suddenly become a speed brake.

I don't understand how anyone could not like the Sikorsky design.
It's sleek and well thought out.
The X3, in my opinion, looks like a hasty engineering attempt to quickly leap frog Sikorsky's development.
Probably explains all of the 'secrecy' surrounding the X3 project.
Okay, to me it looks like a nightmare.

(But I'm also not an engineer, maintenance person, or licensed pilot.
I'm sure someone here would have come along and felt the need to point that out right away.:icon_lol: )
 
Losing an engine in this aircraft would not matter from what I understood from the video. As the outboard props are driven off of the main gear box through a driveshaft system.. Similar to the V-22 Osprey. If you lose an engine on the V-22 there is a driveshaft system that passes through the wings to transmit engine power from the remaining engine to the dead engines prop. Granted on the X-3 it is taking power off of the main gear box to drive both props, but is similar in concept. Even if you lost 1 engine (or both engines) the main rotor would still drive the outboard props during the autorotation. I just do not know how they counteract the main rotors torque either though. At high speeds the rudder plane would help keep it straight. I would think in a hover that one of those props is putting out more thrust than the other to keep it from yawing uncontrollably. Seems like a control nightmare like the Osprey, but at least this will be able to auto rotate it's way back to the ground without the nasty engine cowl rotation issues.
 
Roadburner440 said:
Losing an engine in this aircraft would not matter from what I understood from the video. As the outboard props are driven off of the main gear box through a driveshaft system.. Similar to the V-22 Osprey. If you lose an engine on the V-22 there is a driveshaft system that passes through the wings to transmit engine power from the remaining engine to the dead engines prop. Granted on the X-3 it is taking power off of the main gear box to drive both props, but is similar in concept. Even if you lost 1 engine (or both engines) the main rotor would still drive the outboard props during the autorotation. I just do not know how they counteract the main rotors torque either though. At high speeds the rudder plane would help keep it straight. I would think in a hover that one of those props is putting out more thrust than the other to keep it from yawing uncontrollably. Seems like a control nightmare like the Osprey, but at least this will be able to auto rotate it's way back to the ground without the nasty engine cowl rotation issues.
Click to expand...

Ah okay.
And just want to add, I like Eurocopter as well as any helicopter manufacturer.
They have had some awesome designs over the years as well, that speak for themselves, i.e. Super Puma, EC-135 and 145, etc.
So no disrespect intended towards them.
I guess this just seems like a real tangent in their design for the X3 as far as my little brain can handle.
 
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