First Hover Flight Test of X-50A Dragonfly

kbielefe writes "On Wednesday, flight testing began on the X-50A dragonfly canard rotor wing unmanned aircraft. For those of you not familiar with the dragonfly, its rotors work like a helicopter for takeoff, hovering, and slow-speed manouvering, and then lock into place like a fixed-wing aircraft for cruising. The X-50A's reaction drive makes it "much lighter, simpler and more affordable to operate and support than traditional rotorcraft." And the technology is scalable to larger, manned vehicles. Truly a revolutionary aircraft, with a multitude of potential military and commercial applications." There are some more photos and artwork.

Comments

That was fast

[teklob]

The poll predicted flying cars within our lifetime.
That sure was fast...

Deathtrap?

[The Snowman]

So far, our attempts at bridging the gaps between helicopters and fixed wing aircraft have met with disaster. Take the Osprey, for example. I don't know who it was but he said that it took the worst features of both types of aircraft and mashed them together with poor engineering. Hopefully this new aircraft does not suffer the fate of the Osprey... and her pilots.

Re:Deathtrap?

[bellers]

Incidentally, the Osprey program this week just surpassed 1000 flight hours for the program. It's racked up lots more flight time since the grounding and reengineering interval from 18 months ago.

Did you know that in the 50's the Army almost decided not to use helicopters at all after about a hundred soldiers were killed during trials of the Piasecki helicopters? There were people in the Army who were screaming that it was criminal to keep putting men into helicopters.

While I think that the Osprey getting grounded for a year and a half while they fixed the safety-critical problems was appropriate and justified, I'm glad that it's back in the air, and I think that it can really change the face of airmobile combat.

Re:Deathtrap?

[Smidge204]

Here's a hint:

There are (thousands?) of Harriers in service, and surprizingly few incidents compared to the number in use (and how they are used - eg in an actual conflict).

They built 10 Osprey V-22 aircraft for testing. In April of 2000, one V-22 crashed during a test flight and killed 19 marines. That alone is nearly two people dead for every craft ever built. (Note: Check date, might be wrong!)

Which do you suppose is the safer technology?
=Smidge=

Re:Deathtrap?

[sllim]

Can I assume you are a 19 year old AMERICAN college Sophmore?

Yeah, actually I do think you should at least have heard of this.

The Osprey is supposed to be a replacement for the very aged Chinook helicopters.
If ever the military had a vehicle that outlived its usefulness it was the Chinook.
My father was in 'Nam and he tells me that he couldn't get out of those things fast enough. They were flying bullseyes as far as he was concerned.

The Osprey has the range and speed of a propeller aircraft but the VTOL capability, and the hover ability of a helicpoter.
This is acomplished by putting extremely large propeller (turboprop) engines on the end of the wings. The largest damn propellers you are ever going to see. The ends of the wings actually rotate 90 degrees to facilitate take off and landings.

When they first started testing this thing they found a lot of flaws. Some where engineering problems, but there is one nasty one they have been working on.

The engines can create an unusual vortex that has never really been seen before. When this vortex happens they loose lift and control of the aircraft and it crashes.

Is it a bad aircraft that we need to give up on?

I don't really know.

John Glenn seems to think the Shuttle's are flying death traps and we were better off putting capsules on top of rockets.

The Hubble was a real mess when it was first put in orbit as well. There was an enormous public outcry after the press labeled it 'a failure'.
Hmmmm some failure.

The B-1 bomber also suffered a number of crashes in testing.

Aviation is HARD and DANGEROUS. Someone else already said it for me, it is about time we took the 'pilot' out of test pilot. I can only imagine what the difference in public perception would be if the Osprey had gone through an unmanned testing phase.

The Osprey does hold tremendous promise though. If we can iron out the problems in it, it really would be a new category of aircraft. Something that can economicaly provide city to city air service, something that can bridge the gap between helicopter and airplane.

While I am not yet convinced that they can get a grip on the vortex problem, I am very far away from saying they need to give up.

Re:Deathtrap?

[afidel]

I guess you never heard of Viatnam where helicopters saved so many lives that they literally can't be counted. Just because a handfull of helo's have been taken down by barages of light arms fire doesn't mean the tech should be abandoned. Heck fewer people probably died from crashes then from a single convoy trying to escape by road vs similar circumstances.

Re:Deathtrap?

[Wyatt Earp]

The Harrier has a high rate of failure.

http://www.latimes.com/news/specials/harrier/la- ha rrier-day1.story

"Over the last three decades, it has amassed the highest rate of major accidents of any Air Force, Navy, Army or Marine plane now in service. Forty-five Marines have died in 143 noncombat accidents since the corps bought the so-called jump jet from the British in 1971. More than a third of the fleet has been lost to accidents."

"If the Harrier had been decisive many times in battle, we would all still regret horribly the tragedies of the pilots who have been killed, but at least you'd be able to say that the Harrier made a difference," said Philip E. Coyle, the Pentagon's chief weapons tester from 1994 to 2001.

"What makes this situation so difficult is that we just don't have that kind of battlefield record to support the accidental deaths."

In the Persian Gulf War in 1991, the hot thrust-producing nozzles in the heart of the fuselage -- the devices that allow the Harrier to rise and balance in the air -- made the plane a magnet for heat-seeking missiles. Its loss rate was more than double that of the war's other leading U.S. combat jets. Five Harriers were shot down and two pilots died.

"It's the most vulnerable plane that's in service now," said Franklin C. "Chuck" Spinney, who evaluates tactical aircraft for the Pentagon. "You can't hit that thing without hitting something important."

http://www.nationaldefensemagazine.org/article.c fm ?Id=303

"The AV-8B Harrier--a single-engine attack jet that can take off vertically and hover--has a mishap rate of 12 per 100,000 flight hours, among the highest in the U.S. military aviation community. But only one-third of Harrier mishaps are caused by human error, Dirren said. "Two-thirds [of the mishaps] are related to the aircraft failures."

http://www.globalsecurity.org/military/systems/a ir craft/av-8-variants.htm
"In 1982, after eleven years of AV-8A operational flying, including 55 peacetime aircraft losses, the Commandant of the time (Gen Robert Barrow) asked the Harrier community to address the serious problem of flight safety. The impetus for his concern was "a high mishap rate within the AV-8A community... anticipated continuing turbulence... and a pressing requirement to reduce the mishap rate in order to provide the assets needed for successful transition to the AV-8B." At the time, the community had a cumulative Class A rate of 39 per 100,000 flight hours."

"By 1998, USMC Harrier operations (including Naval Air Systems Command) had resulted in 17 fatalities, one permanent disability and 68 AV-8B aircraft lost. With a cumulative Class A mishap rate of 12.1 per 100,000 flight hours, the AV-8B has consistently outpaced all USMC aircraft types in this statistic."

The FAS website estimates 815 Harriers built in all models all the way from the Kestrel and P.1127 test planes
http://www.faqs.org/docs/air/avav83.html

Re:Deathtrap?

[Moofie]

Uh, so how many Marines can you deliver into hostile territory with an A-10?

I'm pretty sure the number is awfully close to zero.

There are NO armored airborne personnel carrying vehicles. Zero. That means, if you're flying in a C-130 or a Sea Stallion, that there is pretty well nothing between you and fiery death at the hands of bad guys.

It's a problem that is solved by tactics. The Osprey permits a larger variety of tactics (because it's faster and longer-ranged than other heavy lift helicopters).

Being in the Army is dangerous. That's what soldiers sign up for. It's up to the engineers (that's me) to provide them with the best possible hardware to complete their missions, but there is no such thing as a "safe" combat insertion vehicle.

Re:Deathtrap?

[bbaskin]

The biggest problem here was a question of tactics. Army doctrine (now being adjusted) still called for coming to a hover before firing weapons. This obviously exposes the aircraft to high risk small arms fire. Marine doctrine on the other hand has helo pilots firing on the run, not slowing below 60 knots in combat. This difference accounts for much of the combat robustness of the Cobra over the Apache. In fact, before the war, I believe the Marines upped their minimum combat speed.

That said, landing involves stopping, and is always risky. The V-22 has the ability to enter and egress an LZ faster and quiter than any other current rotary wing aircraft. I doubt many on /. have seen/heard a V-22 approach an LZ at 100 feet AGL in airplane mode. It is nearly silent until a 100 or so yards away. Transition can be quick (15s) land, dump cargo, and transition to forward flight again. Because of this reduced exposure/announcement time, the V-22 is more survivable than an old CH-47 or CH-46.

Damn those Aerospace Engineers

[MikeDawg]

I'm must be technically challeneged when it comes to understanding aerospace terms. But can somone please explain to me why this thing doesn't need an anti-torque mechanism (tail rotor). The advanced terms Boeing uses on the website make no sense to me.

By using a unique reaction-drive rotor system, the CRW concept eliminates the need for a heavier and more complex mechanical drive train and transmission, as well as the need for an anti-torque system.

Does this actually mean something, or is it just a bunch of big words to confuse the general public?

Re:Damn those Aerospace Engineers

[SupaMegaBuffalo]

Does this actually mean something, or is it just a bunch of big words to confuse the general public?

A bit of both.
Conventional helicopters need a tailrotor because main rotor is spun by a mechanism that is fixed to the body of the aircraft which tends to spin the body around too. This thing seems to use a tip-jet mechanism to spin the main rotor, ie the tips of the blades contain little jet nozzles to spin it around and since it isn't mechanically fixed to the body it won't tend to spin the body around too.

Sorry if that didn't as much sense as i wanted it to, i haven't slept in 2 days.

Re:Damn those Aerospace Engineers

[bellers]

It means that the reaction gases generated by the turbine engine are routed out through the rotors and to the rotor tips, making them move.

It means that there's nothing inside the vehicle, cranking the rotor around, so the vehicle never tries to crank itself the other way.

Re:Damn those Aerospace Engineers

[Captain Nitpick]

Doesn't make sense...Newtons law..

Ah, but that's exactly why it does make sense.

In a conventional helicopter, the rotor is spun by a driveshaft coming up into the center of the rotor. This creates a torque on the rotor, spinning it. By Newton's third law, there is an equal but opposite torque applied to the rest of the helicopter, causing it to rotate in the opposite direction. Thus, the tail rotor.

In the Dragonfly, hot gas is exhausted at the rotor tips, in a direction perpendicular to the rotor's axis. Since the gas is travelling down the rotor axis, a force must be applied to cause it to change direction, and Newton's third law again says that a complementary force will exist on the exhaust housing, and thus the rotor tip. This force produces the torque to spin the rotor.

Since no torque is applied to the rotor by the helicopter, no torque is applied to the helicopter by the rotor.

Re:Great technology

[Total_Wimp]

"I love how the pictures just have to include one of these plans shooting a missle. You'd think the atomic bomb would've taught us all a lesson."

Umm.... It's a military project. Maybe it's time we come to grips with the grim fact that military projects sometimes include missles.

TW

Re:Could be good for general aviation...

[transient]

The FCC would never approve this vehicle

Then it's a good thing the FCC has nothing to do with airworthiness certificates. ;-)

Re:Time flys...

[Geno Z Heinlein]

Page is out of date by almost a year.

Wow. They've had a year to correct the typo "f light test" (first paragraph, second sentence)?

Maybe they should switch their proofreading staff to metric. :-)

Fairey Rotodyne

[dubstop]

The Fairey Rotodyne was built nearly fifty years ago. Like the Dragonfly, it used (what was then called) tip-jet rotors, so there was no need for a counter-torque rotor on the tail.

The Rotodyne was advanced technology for its day, but it was killed by the politicians.

Some notes...

[mnemonic_]

"The engines can create an unusual vortex that has never really been seen before. When this vortex happens they loose lift and control of the aircraft and it crashes."

Vortex ring states are common to all rotary-wing aircraft. It involves a toroid-shaped volume of air surrounding the rotor disc, in which air pushed downward is recirculated into the top of the rotor disc, instead of pushing against the ground. All helo pilots are trained in how to avoid them and attempt to recover from them. It is a subject of thorough investigation in aerodynamics, and a problem inherent to every helicopter. What makes its presence in the V-22 significant is that even a mild vortex ring state in one of its rotors can cause a drastically sharp roll movement (due to uneven lift on both sides) that is very difficult to recover from.

"The B-1 bomber also suffered a number of crashes in testing."

The B-1B has also proven to be a hangar queen with tremendous operating costs, going against your point of "here are some aircraft which vindicated themselves in actual usage".

I do agree that tilt-rotor technology is the logical evolution of transport helicopters. This isn't just some novel "hey that's neat" offshoot of helos; this is the next generation of rotary-wing tech, something that will eventually replace Chinooks, Sea Knights, Mi-6's and the like.

they're "flaky"!?

[el_guapo]

whilst it is entirely true that they're FRAGILE (ie: you can shoot most down with a pistol), they are FAR from "flaky". aside from the fragility issue, they are no different from fixed wing aircraft in their "flakiness". they simply trade high speed for the ability to hover, that is ALL. and, incidentally, there is no fix for the speed issue in a conventional chopper, at some "N" speed, the retreating rotor blade stalls and the bird flops over.
most people don't realize that helicopters share EVERY flight characteristic (sans high speed) with a fixed wing aircraft, including the ability to "glide" (they call it autorotation in choppers, the air rushing up through the rotor keeps it spinning, and you flair at the last moment. every helo pilot can do it, and you land without a scratch as long as the surface is apporpriate)