Another first from the "don't apply if your resume doesn't say MIT on it" department. The Eurocopter may have been the first to summit Everest, Alan Szebo Sr/Jr may rule the 3D kingdom, but the Hummingbird's got the endurance record now.http://www.darpa.mil/body/news/2008/A160DARPAReleasev4.pdfNow if only the Hummingbird could repeat these stunts without crashing.
"I think fixed wing is better suited to UAV roles than helis."
Depends on the mission - in tight quarters or close to ground, you need a stable hover. However, with the availability of gimballed camera mounts for fixed wing craft and adequate image processing to maintain a visual lock from altitude, I'd likewise agree that the ability to hover thousands of feet above ground level would seem to have limited utility and questionable economics.
I think fixed wing is better suited to UAV roles than helis.
Faster delivery to area of opertation,remember helis have a terminal forward speed.
More fuel effience and longer staying on post.
i dont really see a need for a vertical UAV.
Small UAVS can be hand launch and recover with a net.
The only reason would be takeoff & landing in high altitudes like Afghanistan or Mt. Everest but then the question is why anyone would bother climbing to such a high place.
I dont see the reason for hover at high alt out of ground effect.
Other than making landing and take off vertical and some winching pax or cargo which with our larger helis is in ground effect.
The biggest problem faced by helis is endurance.
The A160T is at first glance a fairly ordinary helicopter, apart from lacking a pilot. But it does have some other special sauce - its variable-speed rotors. Most helicopters now flying spin their blades at a constant rate, which is set for best performance at a given speed, height and load. This keeps the complexity of the transmission and rotor hub down, but sacrifices fuel efficiency and quietness.
The A160T, by contrast, is designed to constantly adjust its rotors to the optimum revs. This is what has let it achieve such a long endurance, and it also - according to Boeing - makes the Hummingbird "four times as quiet" as a normal helicopter in the hover.
Boeing also believe that the A160T will be especially good at hovering high in the air - so-called Hover Out of Ground Effect, or HOGE performance. In thinner high-altitude air, many current helicopters can't actually hover unless they are "in ground effect" - that is, almost touching the ground. (In Afghanistan this is especially common.) Boeing are chuffed to reveal that the A160T has also lately demonstrated HOGE to altitudes of 20,000 feet - though they don't say how much payload it had on board, nor how much fuel. It surely won't have been as much as on the endurance flight - Boeing do specify that the HOGE trial lasted only 2.9 hours, with just 7 minutes of hovering. Even so, the Chinook - one of the most capable manned helicopters currently available, very popular in Afghanistan - struggles to hover OGE at 20,000 feet with anything on board at all.
Comments
Depends on the mission - in tight quarters or close to ground, you need a stable hover. However, with the availability of gimballed camera mounts for fixed wing craft and adequate image processing to maintain a visual lock from altitude, I'd likewise agree that the ability to hover thousands of feet above ground level would seem to have limited utility and questionable economics.
Faster delivery to area of opertation,remember helis have a terminal forward speed.
More fuel effience and longer staying on post.
i dont really see a need for a vertical UAV.
Small UAVS can be hand launch and recover with a net.
Other than making landing and take off vertical and some winching pax or cargo which with our larger helis is in ground effect.
The biggest problem faced by helis is endurance.
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The A160T is at first glance a fairly ordinary helicopter, apart from lacking a pilot. But it does have some other special sauce - its variable-speed rotors. Most helicopters now flying spin their blades at a constant rate, which is set for best performance at a given speed, height and load. This keeps the complexity of the transmission and rotor hub down, but sacrifices fuel efficiency and quietness.
The A160T, by contrast, is designed to constantly adjust its rotors to the optimum revs. This is what has let it achieve such a long endurance, and it also - according to Boeing - makes the Hummingbird "four times as quiet" as a normal helicopter in the hover.
Boeing also believe that the A160T will be especially good at hovering high in the air - so-called Hover Out of Ground Effect, or HOGE performance. In thinner high-altitude air, many current helicopters can't actually hover unless they are "in ground effect" - that is, almost touching the ground. (In Afghanistan this is especially common.) Boeing are chuffed to reveal that the A160T has also lately demonstrated HOGE to altitudes of 20,000 feet - though they don't say how much payload it had on board, nor how much fuel. It surely won't have been as much as on the endurance flight - Boeing do specify that the HOGE trial lasted only 2.9 hours, with just 7 minutes of hovering. Even so, the Chinook - one of the most capable manned helicopters currently available, very popular in Afghanistan - struggles to hover OGE at 20,000 feet with anything on board at all.
I wonder what the swash plate looks like under the covers.
I think endurance is more important than altitude.