Comments on: First Flight of Sikorsky X2 Demonstrator

By: Observer

Observer — Tue, 03 Feb 2009 19:25:00 +0000

If the goal is to produce prototypes, it seems like Piasecki has already been here and has a leg up on Sikorski. Last year, Piasecki (originator of the dual rotor system that led to the YH-16, CH-46 and the CH-47) under contract to the ARMY completed their phase-one demonstration of a vectored-thrust compound helicopter using a significantly larger, Sikorski UH-60 airframe. For their design, they retrofitted a ducted fan and wing stubs onto an BlackHawk airframe and proved enhanced speed and vibration performance. As for looks and appearance, this airframe looks much closer to what you would expect from a vertical craft too as opposed to having the dual rotors on top of each others.

By: C. Foskey

C. Foskey — Thu, 04 Sep 2008 18:05:00 +0000

Greg
What makes you think that Comanche tech has not made its way in to X2, S76D, H92, UH60, CH53K etc?
Again, I think a lot of you guys on here keep forgetting that this craft is just a technology demonstrator. It will never be produced in this configuration.

By: Greg

Greg — Wed, 03 Sep 2008 19:10:51 +0000

Why not just make an x2 comanche. Then you have an escort for the JHL. Most of the research for the comanche has been paid for. Why not use it in the next generation attack helicopter?

By: Cole

Cole — Wed, 03 Sep 2008 00:31:50 +0000

Dennis, read the opening line of your link which talks about tilt rotors being around since the 50s. Look at how many tilt rotors have been operational during that time vs. helicopters that originated around the same timeframe.
Look at the 900 lb weight of your air vehicle which increases by 200–400 lbs with pilot(s). Look at the measley 100 hp engine to power the batteries driving the electric motors. Show me an electric car or hybrid that weighs the same as the high performance conventional engine.
Finally, check out the powerpoint that I posted in the UH-60M article above and see how aircraft with equivalent power have much different payloads depending on whether helicopter or tilt rotor. Hint.…the tilt rotor never wins.
Now look at this little X2 gem with 8 blades producing lift in a much smaller rotor diameter allowing enhanced lift in a small LZ with similar to tilt rotor speeds. Methinks that rumors of the demise of helicopters are more than a bit exaggerated.

By: Dennis

Dennis — Tue, 02 Sep 2008 20:08:07 +0000

I appreciate Sikorsy’s efforts; but if you look at this:
http://www.gizmag.com/falx-to-debut-hybrid-electric-tilt-rotor-aircraft-with-inbuilt-solar-c/9234/
You realize that even with it still on the drawing board, this design is going to make helicopters and the Osprey so much overcomplicated / obsolete junk.….
Sikorsky needs to not make the same mistake the railroads did, they are not in the business of railroads, but of transporting things. With this thought in mind you would think the rail barons would have started truck and aircraft companies.
No, most of them just went out of business.…
I think the helicopter is not long for this world

By: C. Foskey

C. Foskey — Mon, 01 Sep 2008 17:29:03 +0000

RE Spencer:
Cartercopter is a joke. They break the mu=1 barrier than destroy their prototype and do nothing in the following 4 years.
You other guys have to realize that this craft is just a technology demonstrator. We created this as a platofrm to study the entire concept to be applied to specific mission profiles. Actually, the army re-funded X2 research for JHL, after they had claimed in 2006 that they were only looking at tilt rotor solutions. The X2 tech package looks promising, and our concepts utilize it in an osprey sized aircraft which, if you may recall, can autorotate…as all X2 based designs can.

By: pedestrian

pedestrian — Sun, 31 Aug 2008 14:58:07 +0000

I believe it will become a cheap version of Ospreys. This does not fly as fast as Ospreys, but cheaper to produce, cheaper to maintain. It would rather fit into the hi-lo mix with the Ospreys. The Ospreys would be the hi (quality approach) and the X-2 offsprings will be the lo (quantity approach). With a high price tag on Ospreys, a less speedy but lower price tag of the X-2 offsprings will provide quantities versus quality of the Ospreys, just like the hi-lo mix of Raptors and Lightning II.
>Now that would be an appropriate Osprey escort.
I had that in mind too. Probably not any other platform would achieve such high speed. It is not fast as Osprey, but faster than any other propelled VTOL excluding Osprey itself. Osprey has difficulties for weapon bays to be added due to the rotor blade being in the way. The X-2 offspring will have more freedom to add on weapon bays just like other helos. Both has advantages and disadvantages. These are not rivals, but something that would cover the weakness of the other.

By: jon spencer

jon spencer — Sun, 31 Aug 2008 11:07:25 +0000

Only one thing to say,
http://www.cartercopters.com/

By: P.M.Lawrence

P.M.Lawrence — Sat, 30 Aug 2008 09:05:07 +0000

You don’t need to bother about having rigid rotors and making them counter-rotate if you go the Fairey Rotodyne route. With that, vertical flight was achieved with tip jets ducted from the main engines to eliminate torque, slow forward flight made the rotor work like an autogyro, and fast forward flight was practical because the wings provided most of the lift and unloaded the rotor enough that the blades didn’t need to adjust so much and the hingeing approach was still good enough. The Rotodyne managed speeds above 200 knots in the 1960s, so a modern development should be competitive even today.

By: Scathsealgaire

Scathsealgaire — Sat, 30 Aug 2008 01:07:57 +0000

@ hex16 “What is the concern about rotor tips going supersonic“
If the the tip goes super-sonic the resulting shockwave would tear(best description for lay person) the tip off, unless the whole thing was designed ALOT HEAVIER.
In the original teasting of supersonic jets they ended up with massive gouges in the air frame, if this happened in the thin and relatively light rotor blades the tips would tear off because extremely high pressure air would blast it’s way through the metal of the blade.
Kind of like sand blasting, in high speed. And through metal.