From Wired's DangerRoom site.
On April 30, the Navy awarded Aerovel a second development contract to improve the Flexrotor’s engine and remote controls. The ultimate goal is to develop a version of the ‘bot equipped with sensors and capable of operating from small ships. “With Flexrotor, the two biggest benefits to sailors and Marines would be the ability to do extended maritime surveillance from a ship, and to do so with a small footprint,” said ONR’s John Kinzer.
As depicted in the video above, the Flexrotor takes off vertically like a helicopter, propelled by its roughly five-foot, tip-mounted rotor. Once it climbs high enough, small winglets pop out of the robot’s tail end and it tips over and dives, transferring lift from its rotors to its 10-foot-wide wing mounted in the middle of the tube-shaped body. The rotor becomes a propeller, and Flexrotor cruises along like any conventional airplane. The first drone’s first test transition between copter and plane modes took place in August.
Comments
Take a look at the small propellers at each wingtip.
Huh, I stand corrected! I saw Tad speak at an AUVSI conference and got a good look at the Flexrotor, and at least in person it appeared to be fixed-pitch. He says this will be able to land on a small platform mid-ocean, and I didn't see how that would work without some sort of pitch control....
Look at around 2:53 there is a quick flash of the prop which suggests to me, a quick cyclic flare.
What else explains the increased profile of the blades at that moment?
How do we know the main rotor is fixed?
If that is the case - it would require them to rely on prop speed differential for (yaw) and prop sum for (roll).
I think this is more effectively accomplished with a dual rotor and control surfaces.
I would use split ailerons (ie each aileron is also a brake).
The main rotor/propeller disk is fixed, and large diameter- perhaps they are using gyroscopic precession for control?
Hey Jack, yes I agree the way you described the hover controls seems to be logic and explains the funny propellers at the end of the wing. They could use their tail-actuators for control, however these are retracted!
Have to remember these folks bought us the Scan Eagle they know what they are doing.
There's no pitch control on the main propeller, so landing on a pitching/rolling deck is going to be an interesting feat.
The quadshot is a meld of lots that came before, the clever bit is managing the transition. Containing yaw is a real issue with small platforms. Huge rudders are the order of the day ;-)
I'm pretty sure this uses a full cyclic control on the main rotor for control in launch/land mode.
It's a helicopter at that point.
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