Next Generation Rotorcraft

[Dave_Jackson]

The article Manufacturers: Technology Will Make Rotorcraft Faster, Safer
(http://www.nationaldefensemagazine.org/archive/2011/May/Pages/ManufacturersTechnologyWillMakeRotorcraftFaster,Safer.aspx)a nd the linked [Related Content] contain interesting opinions on the future of rotorcraft.


Dave

[riff_raff]

Dave,

Thanks for the link.

Although I don't know how much safer "new technology" will really make rotorcraft. Much of the problem has to do with the way rotorcraft are typically operated versus fixed wing aircraft, and not so much a lack of technology. As for faster rotorcraft, compounds and tiltrotors will definitely be faster than conventional rotor systems. But they are also somewhat more complex drivetrains, which usually means less reliable.

As for which technology the US military will adopt for their new generation of rotorcraft (ie. JMR), that will depend on how they finally decide to use the aircraft. Tiltrotor is probably better for long, high and fast. Compounds may be better for short and low, and present less development risk.

Sikorsky is smart by using their own money to build and fly an S-97 right away. They'll be flying their JMR TD while the other competitors are still doing trade studies.

[skadi]

what? The X3 has also an coaxial rotor? So it must be a stealth one :E:E

skadi

[Rigga]

Surely the question is: What do future operators want a future rotorcraft to do?

Is it all about speed and lift capability? or comfort and safety...?


Rememeber that Edison used to announce his next invention - then try to meet his declaration!

[Dave_Jackson]

The following excerpt is intriguing. Particularly since Sikorsky has 11 patents related to a Variable Diameter Tiltrotor (http://www.unicopter.com/1621.html).

"Sikorsky officials also plan to investigate what it may be able to do with tilt-rotor technology.

We are looking at a very broad set of options,” Van Buiten said. “They range from the lowest risk, lowest cost and significant enhancements to what they already have all the way up to new stuff like X-2.” Tilt-rotors may be a better fit for certain missions, he acknowledged."

Perhaps they are again realizing the limitations of the ABC concept that are presented by the reverse velocity region at high speed.

Dave

[riff_raff]

Dave-

I doubt we'll ever see a useful VDT. Designing a practical and reliable extend/retract system for the blades is a very difficult problem, and I would imagine the problem gets exponentially worse as the blades get larger. Looking through those Sikorsky patents, it's obvious they never came up with a good solution. That's likely why they abandoned the idea a few years back.

Their X2 coaxial configuration also has some things they need to work on. As the blades get longer and the speeds get higher, I would imagine that at some point the vertical separation needed between the advancing and retreating blades may become excessive.

[Dave_Jackson]

riff_raff,

Yes. It must be difficult for today's CEOs to put current profits into long-term research and development when neocapitalism demands that companies keep the value of their stock up.

Dave

[Flyt3est]

It must be difficult for today's CEOs to put current profits into long-term research and development when neocapitalism demands that companies keep the value of their stock up

Everybody wants value for money, governments are under pressure to maximize the bang / buck equation on behalf of the tax payer, defense contractors are being squeezed to tight profit margins and 2nd / 3rd / 4th tier suppliers everywhere are cutting each other's throats to stay in business.. Couple that with DoD development programs hitting the public eye for huge cost over-runs and all of a sudden you have all of the factors which make R & D work ever more difficult to justify.. Sad but true.

FT