Hybride d'helicoptère et d'avion

[Arka_Voltchek]

Intéressant comme concept, ça peut poser moins de problème que de basculer totalement les rotor. Basculer partiellement une aile est quelque chose de bien mieux maitrisé. Reste à étudier les perturbations aérodynamique que ça causera.

@+, Arka

[BPCs]

http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a22567a02-9a59-4e2a-8553-07e369cb2829

Encore un helo bizarre ... birotor transversal ... avec tilt wing mais pas pas tilt rotor ...

Finalement ce projet pourrait faire une mécanique plus simple, sans les soucis de vortex généré par la balance complète du rotor à 90° comme dans le tilt rotor...???

Il semble que la bascule des ailes permette d'incilner les rotor un peut plus qu'a la normale accroissant leur role de propulsion ... et reléguant la sustentation aux ailes.

Aux allure plus faible les aile se redresse et les rotor reviennent "a plat" fonctionnant comme un helo classique avec juste un petit peut de portance des ailes braquées.

Sur la photo, le Rotor semble clairement fixe

Donc quand l'aile se redresse, le plan des pâles se retrouve parallèle au sol donc max de poussée verticale à laquelle se surajoute l'effet lié à l'inclinaison de l'aile qui modifie l'angle d'attaque pour faciliter le décollage.

En vol, l'aile redevient horizontale d'où bascule du rotor vers l'avant avec de ce fait effet propulsif

L'apport des ailes est alors comme dans les modèles hybrides sans doute de permettre de dépasser le problème de la limitation de la vitesse de pale ?

Mais il y avait eu par le passé au moins des tilt wing parfois à réaction (projet allemand) mais jamais clairement sur un mode rotor d'hélico à ma connaissance :

ainsi le projet X-18 :

[Marcus]

Mais il y avait eu par le passé au moins des tilt wing parfois à réaction (projet allemand) mais jamais clairement sur un mode rotor d'hélico à ma connaissance :

ainsi le projet X-18 :

De nombreux pays ont testé cette formule dans les années 60. Les prototypes de cette époque n'ont pas convaincus.

J'étais tombé sur un article expliquant que le défaut de la formule tilt wing basique de cette époque est qu'au décollage, l'aile est verticale ce qui gène la prise de vitesse. Le passage en mode avion est donc ralenti. La solution consiste à augmenter grandement la puissance ce qui fait perdre de l'intérêt à la formule.

C'est l'une des raisons qui font que le V22 a une aile horizontale fixe. Même si cette position n'est pas idéale à cause de la perte de puissance au décollage.

Si on suit cette logique jusqu'au bout, un bon convertible devrait avoir :

- des ailes basculantes,

- des moteurs basculants.

Les deux de maniére complétement indépendante.

Un tel système est probablement réalisable mais risque d'être couteux et dangereux.

Je pense que c'est pour cela que l'on voit apparaitre des solution de compromis comme :

- le Karem que tu présentait

- Le Bell que g4lly a trouvé.

A regarder

[BPCs]

"Ka-90

The most radical concept is the Ka-90, described as a “high-speed vehicle of rotorcraft type”. Kamov general designer Sergey Mikheyev says the Ka-90 has been a “long evolving” concept of “helicopter at take-off/landing, and airplane in cruise flight”. In essence, the Ka-90 is a “variable-geometry” air vehicle with two separate propulsion systems, one for cruise and one for take-off/landing.

Proposed in 1985, it was shelved after the collapse of the Soviet Union. Now dusted off, it is back under work. A scale model revealed at the HeliRussia 2008 show in May provided evidence of the Ka-90 having a turbojet in the rear fuselage for high-speed level flight and retractable rotor for take-off and landing. Presumably, the lift in cruise flight will be generated by a “wing”, in this case a huge, specially shaped container above the fuselage to which the rotor blades are retracted after being folded. According to Mikheyev, the Ka-90 is intended to have a cruise speed of 378kt.

[Philippe Top-Force]

Ton Ka 92 est aussi superbe, tu as des infos dessus.

[BPCs]

Y aussi cela mais j'ai qq problèmes (pour le moment à tout comprendre)!

http://www.avia-n-aero.ru/photo.php?category_id=596&parent_id=564&photo_id=4916&countdisplay=&start=0

et qq data sur secretprojects :

http://www.secretprojects.co.uk/forum/index.php/topic,2766.30.html

Ka-92 - 227-243 kts cruising speed

[BPCs]

2009/02/23

High speed rotorcraft / Derschmidt rotor system

.

Helicopters have a problem; they're slow.

We wouldn't accept that problem if there wasn't one strength; the ability to take-off and land vertically (VTOL) and to hover.

The practical limit for dominant layout helicopters is 300 km/h, and decades of experiments didn't really change that.

The V-22 Osprey tilt-rotor is slightly faster, but its cruise speed is still below 500 km/h and it's extremely complex and expensive. It's pretty much a niche design that cannot beat comparably complex and expensive heavy-lift helicopters in practical transport capability.

The helicopter's problem is an extension of the problem that almost doomed propeller aircraft. The propellers of WW2 aircraft had a small radius, but many revolutions per minute - the tips approached Mach 1 and that caused such great aerodynamic troubles that propellers were and are impractical for aircraft faster than 800km/h.

The V-22's rotors have less revolutions per minute but bigger radius, thus limiting its speed as well - even below 700-800 km/h because of the requirement for good lift at take-off and landing. Today's propeller aircraft aren't much faster than 600 km/h anyway.

The helicopter with its horizontal rotor that tilts only slightly to produce forward thrust has an additional problem; its indicated air speed needs to be added to the relative rotor tip speed because the rotor tip moves forward half of the time.

Some of the proposed solutions for the problem had the rotor turned into vertical (tilt-wing, tilt-rotor, tail-sitter) while others reduced the rotor to a take-off and landing component; the most extreme proposals had pusher propellers and stub wings and had the rotor folded in flight to reduce drag.

All these proposals weren't exactly a good solution to the problem, but VTOL is still considered to be extremely desirable and thus we keep researching for solutions.

There's one quite obvious solution left that gets usually little attention in English-language writings about the subject; a third most obvious approach:

Do the same as with the wings; swept wing geometry solved the Mach problem for wings, and it can theoretically do the same for rotors.

I don't know exactly why we don't simply use sickle-shaped rotors, but there's another approach that lends from another solution used by fighters; variable geometry. Variable geometry wings were very fashionable in the 60's and solved some requirement conflicts for aircraft like the Panavia MRCA Tornado.

The corresponding helicopter rotor design was the Derschmidt rotor.

The Derschmidt rotor system was tested in 1964-1966 in the experimental helicopter Bölkow Bo 46 and this system uses rotor angles of up to +/- 40°.

Estimated speed potential of the Bo 46 was 500 km/h, it was tested with up to 615 km/h in a wind tunnel and total potential with additional thrust and wings was estimated at 700 km/h.

A helicopter with such a rotor system might today have the same speed range as a V-22 due to the forward thrust of the gas turbines and retractable landing gear.

The lesson was pretty much that the technology of the 60's couldn't handle the challenge. Both control and materials challenges were too great.

It's a recurring topic in German aviation literature that today's or future technology might be up to the challenge and create a high-speed helicopter.

The present helicopter research is more oriented towards ongoing military helicopter programs and near-term solutions for Eurocopter's success, though.

The political interest in renewed research seems to be small.

Nevertheless, it deserves some attention next to the usual suspects that are being preferred by the Americans like Piasecki's compound helicopters, tilt-rotors, ABC rotors and alike.

Sven Ortmann "

[BPCs]

encore un !

"Rotor-heads, enjoy!

This is Lockheed Martin's latest patent filing for a new aircraft, and it completely stumps me. The patent document [see below] explains the "wings are directly driven by engines located at the wing tips. The aircraft incorporates large-span, high aspect ratio blades or wings that are joined at their outermost tips to improve the structural characteristics of the wings. ... The design enables vertical takeoff and landing capabilities, thus simplifying launch and recovery operations for the aircraft.

Interestingly, the publication of this patent filing on May 21 came only two weeks after a senior Bell Helicopter executive told me thinks Lockheed wants to jump back into the helicopter market (remember the Cheyenne?).

[g4lly]

encore un !

"Rotor-heads, enjoy!

Un mix des modele ejectant les gaz en bout de rotor et de contrarotatif ... c'est quoi l'interet? la motorisation sur le rotor assur e déjà l'anti couple nan?

[BPCs]

Un mix des modele ejectant les gaz en bout de rotor et de contrarotatif ... c'est quoi l'interet? la motorisation sur le rotor assur e déjà l'anti couple nan?

Je trouve que cela fait usine à gaz (même éjecté en bout de rotor :lol:)

Quand on pense au crash avec abandon de programme à la clé du X-50 voire du TR-918, on se dit qu'on est pas près de le voir sur le pont d'un LHD celui-là (on note au passage mon ton zabsoluement pas provoc, alors que zuzuellement je l'aurais posé sur mon BPC préféré ;))

J'ai l'impression que la baston va être entre le X2 de Sikorsky et le Piasecki avec le X3 d'Eads et le pseudo X2 des russes en outsider plus tardifs...

[BPCs]

D'ailleurs j'ai trouvé cela sur ARES :

"Helo Speed Freaks Speak Out

Posted by Graham Warwick at 6/8/2009 9:00 AM CDT 

At the American Helicopter Society's Forum 65 gathering in Grapevine, Texas a week or so back, several of the speakers talked about the need for speed. This is coming out of operations in Iraq and Afghanistan, for two reasons.

First, the V-22 tiltrotor has set a new standard for speed around the battlefield. Secondly, as its rotor has to produce lift and thrust, a helicopter struggling to lift its load in a hot day at high altitude does not have much oomph left to go fast. The Black Hawk is not a 150kt helicopter in Afghanistan.

A need for speed came out of the Vietnam War also, and resulted in the US Army's 212kt Lockheed AH-56 Cheyenne compound helicopter. But development difficulties, cost overruns and a roles and missions dispute with the US Air Force led to its cancellation. The Army ended up with the AH-64 Apache, and helicopter speeds stayed pretty much unchanged.

(Photo: 1000aircraftphotos.com, Jan Visschedijk Collection)

Now the call for speed is being heard again, and the problem is how to respond. There are no new helicopter programs on the books, or even on the horizon until beyond 2025. Some, like Sikorsky with its X2 Technology, argue it needs a new design to take full advantage of speed and are willing to wait. Others, like Piasecki with its X-49 SpeedHawk, believe today's helicopters can be upgraded and want to get on with it.

Speed is high on the list of needs coming out of the Pentagon's Future Vertical Lift capabilities-based assessment (FVL CBA), which is intended to draw up a science and technology investment plan to support the Pentagon's future rotorcraft. Increased speed is a big piece of two "relatively certain" requirements identified by the study - high-speed VTOL insertion/extraction and multirole ISR/attack.

The problem with the FVL CBA for some in the industry is it's only looking beyond 2020. This is deliberate, to avoid being sidelined by efforts to protect existing helicopter production programs, which run out to about 2018. But with the Army planning block upgrades that will keep the AH-64D and UH-60M in service well past 2025, there seems little opportunity to insert new technology.

Sikorsky, which hopes to fly its company-funded X2 coaxial-rotor demonstrator to 250kt by year-end, says it could deliver a new high-speed helicopter by around 2018 at the earliest. Piasecki says it could compound the Black Hawk sooner and cheaper, but is struggling to get the funding needed to prove its X-49 demonstrator can safely fly beyond 200kt.

[BPCs]

"Warrior Part 2 of 2 from PEO Soldier on Vimeo.

-- Christian

June 3, 2009 07:42 AM | Video Lounge | Discuss (1 comments)

Excalibur Prepping for Test Flight

A prototype for an unmanned aerial vehicle that may one day insert special operators, kill bad guys or fly a wounded Soldier from the battlefield to a base hospital gets a try-out sometime over the next several weeks.

The Excalibur will be tested in a proof of principal flight at Aberdeen Proving Grounds in Maryland under contract from the Army's Aviation Applied Technology Directorate at Fort Eustis, Va. Don't expect the robot plane to be carrying anyone -- at just around 700 pounds the prototype is intended only to give the Army a demonstration of its vertical take-off and landing capabilities.

Patti Woodside, a spokeswoman for the company, told Military.com that Excalibur-maker Aurora Flight Sciences of Manassas, Va., "will be looking for customers and funding" to continue the UAV's development.

She believes the test flight probably will happen in early July, but after July Fourth.

The test version will only be about 13 feet long, have a wingspan of 10 feet and weigh in at just about 700 pounds. The company envisions an operational Excalibur to be 23 feet long, with a wingspan of 21 feet and weigh 2,900 pounds. Though Excalibur's dimension's would be shorter than the RQ-1 Predator, it would weigh more than twice as much.

Aurora says Excalibur would fill a gap between weapon-toting UAVs such as the Predator, which can carry Hellfire missiles, and manned strike aircraft used for tactical air support. The Excalibur would be able to carry any of several types of ordnance, including Hellfire, Advanced Precision Kill Weapon System missiles, Viper Strike laser-guided glide weapons and other small, precision-guided munitions developed or under development by the Pentagon, according to Aurora's Web site.

Company officials at the Air Force Association's symposium in Washington last fall said the UAV also could be used to insert special operators into an area, as well as carry wounded troops out of a combat zone. In addition to its VTOL capabilities, the UAV would be able to take off and land using short runways.

Unlike other UAVs, the Excalibur will not be remotely piloted by someone manning a computer, the company says. The plane will have a high level of autonomy, it says, which means officials can concentrate on mission planning, including finding and designating targets.

The company says Excalibur will reach speeds in excess of 400 knots, but with the ability to loiter at 100 knots.

Bryant Jordan

June 2, 2009 12:26 PM "

[/yhttp://www.youtube.com/watch?v=OTNAfSMF-A0outube]

[Rob1]

A need for speed came out of the Vietnam War also, and resulted in the US Army's 212kt Lockheed AH-56 Cheyenne compound helicopter. But development difficulties, cost overruns and a roles and missions dispute with the US Air Force led to its cancellation. The Army ended up with the AH-64 Apache, and helicopter speeds stayed pretty much unchanged.

Ah, le prétexte des coast overruns... Si je me souviens bien, l'Army a trouvé trop cher de s'équipper de 300 Cheyenne. Elle a fini par prendre des Apache, dont le développement inital coûté l'équivalent de 1200 Cheyenne  :lol:

[g4lly]

Apres le "twin tilt rotor",  le "twin tilt rotor stop/fold" ... "pliant"

http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3aea5a76a7-386c-4a07-9c38-a7c4c6d16d3e

[BPCs]

Et dans la suite de l'article, on voit que cela permet d'envisager ceci :

En fait le problème de ce superbe chasseur ci dessus est alors ceci :

" But while there were aerodynamic and aeroelastic advantages to folding the proprotor, it was decided these were outweighed by the complexity and weight of the stop/fold mechanism and the lack of an engine that could convert from shaft power to jet thrust and back."

car sinon il faut 2 systèmes un pour décoller l'autre pour pousser, une fois le tilt rotor replié

Si on va dans les pages précédentes on voit le proto de Lynx compound qui proposait de convertir une partie de la puissance du rotor en propulsion "jet"

[Invité]

Et dans la suite de l'article, on voit que cela permet d'envisager ceci :

En fait le problème de ce superbe chasseur ci dessus est alors ceci :

" But while there were aerodynamic and aeroelastic advantages to folding the proprotor, it was decided these were outweighed by the complexity and weight of the stop/fold mechanism and the lack of an engine that could convert from shaft power to jet thrust and back."

car sinon il faut 2 systèmes un pour décoller l'autre pour pousser, une fois le tilt rotor replié

Si on va dans les pages précédentes on voit le proto de Lynx compound qui proposait de convertir une partie de la puissance du rotor en propulsion "jet"

l'image date de 1987

[BPCs]

Bah c'est ce qu'ils disent : des concepts qui ont été à la mode puis abandonnés, toujours en attente d'une concrétisation.

Cela est du même registre que les études pour le V-22 Escort :

"In 2003 Bell continued concept development involving attack and escort versions of the tiltrotor for use with both the V-22 and the QTR. These range from reaping the benefits of commonality by mating the V-22 wing and propulsion systems with a different fuselage and cockpit, which would create an attack tiltrotor with A-10 characteristics, to developing a completely new design for a stealthy attack/escort tiltrotor.

A more radical design that has already seen some wind-tunnel time is our Stop-Fold TiltRotor (SFTR) concept vehicle. If a tiltrotor combines the best characteristics of a helicopter and a turboprop, this aircraft will combine the best aspects of a tiltrotor and a jet. The SFTR's unique design allows it to take-off and land like either a helicopter or a turbofan jet. At low speeds (up to 150 knots), it operates like a conventional tiltrotor, but above that speed its rotors can be feathered, stopped, and folded along the nacelles, and the turbofans will convert from shaft drive to thrust - giving the aircraft a speed range of zero to its power limit. High subsonic, or even supersonic speeds are possible with this design. The SFTR provides jet performance while "up and away" with the easy maneuverability, reasonable downwash and hover efficiency of a tiltrotor during the takeoff and landing portion of flight. "

http://www.globalsecurity.org/military/systems/aircraft/v-22-escort.htm

Ce qui devient intéressant c'est de voir des projets d'hybrides chez les principaux constructeurs qui auront ainsi tous tendance à se "marquer à la culotte"

avec pour le moment Sikorsky qui tient la corde pour 2017-18

mais où l'on voit que Bell aurait tendance à proposer ce Concept de stop tilt rotor pour le projet de remplacement de la majorité des hélicos moyens US : les années autour de 2020 vont être rock'n roll  dans le marché des hélicos :lol:

[BPCs]

SIKORSKI X2 LTH MOCK-UP

[g4lly]

SIKORSKI X2 LTH MOCK-UP

http-~~-//www.youtube.com/watch?v=hwusQWZBXjg

http-~~-//www.youtube.com/watch?v=hwusQWZBXjg

[youtube=400,300]http-~~-//www.youtube.com/watch?v=hwusQWZBXjg[/youtube]

[BPCs]

X2 Back in Flight

Posted by Graham Warwick at 7/2/2009 4:06 PM CDT

Sikorsky's X2 Technology demonstrator is back in the air, modified and ready to begin high-speed flight testing with the goal of achieving 250kt. Two flights totalling an hour on June 30 included the first full engagement of the tail-mounted propulsor.

Photo: Sikorsky

Driven from the same T800 engine as the rotors, the variable-pitch propulsor is one of the "X2 technologies". The others include the rigid counter-rotating rotors with their low-drag hubs, fly-by-wire flight controls and active vibration control. Sikorsky quotes chief test pilot Kevin Bredenbeck as saying noise and vibration were "very low" on the June 30 flights, which reached 52kt.

Compare with X2 with Sikorsky's XH-59, which used the same advancing-blade rotor concept, and you can see what changes 20 years of technology development have wrought.

Photo: 1000aircraftphotos.com, Johan Visschedijk Collection

The XH-59 was fast, but it was also noisy, shaky, draggy and thirsty. It needed two pilots and four engines to do what the X2 can do with one pilot and one engine. Or promises to. Sikorsky is running a bit behind schedule, but says it still plans to reach 250 kt by year-end.

[Philippe Top-Force]

Le Bluecopter écologique.

[BPCs]

Sikorsky X2 Files With Engaged Propeller

Jul 13, 2009

Kerry Lynch

Sikorsky's X2 Technology demonstrator recently completed two test flights with a fully engaged the propeller for the first time. The helicopter reached speeds of 52 knots in one test and 42 knots with the propeller providing forward thrust in the second flight. The demonstrator is designed to fly at 250 knots, about twice the speed of current helicopters.

The demonstrator has accumulated more than three hours of flight time at the Sikorsky facility in Horseheads, N.Y. The aircraft will be relocated to Sikorsky's Development Flight Center in West Palm Beach, Fla. this month for continued flight-testing that will lead up to the 250-knot design goal.

The X2 Technology demonstrator incorporates a range of new technologies, as well as a counter-rotating coaxial rotor, to achieve record speeds yet retain low-speed handling, efficient hovering and autorotation safety. In addition to the rotor, the demonstrator is equipped with fly-by-wire controls, hub drag reduction, active vibration controls and an integrated auxiliary propulsion system. Sikorsky said it is "maturing the technology" for use in a range of missions such as rapid air medical response, reconnaissance and special operations.

"The program is progressing extremely well both technologically and from a future applicability standpoint," said Mark Miller, vice president of research and engineering at Sikorsky. "Certainly we've got much more to do, but interest continues to grow among both the military and commercial sectors in how this technology might improve current operations and enable new missions that today are simply not possible with the current helicopter flight limitations."

[BPCs]

Un de plus...

http-~~-//www.youtube.com/watch?v=0qU19kmTVJM&feature=related

 

It Attacks. It Lifts. Will it Happen? - Joint Multi Role

Posted by Graham Warwick at 7/22/2009 9:08 AM CDT

It's still a long way in the future, but the US Army has canvassed industry ideas on potential configurations and technologies for the  Joint Multi Role (JMR), a notional common platform to replace AH-64Ds and AH-1Zs, UH-60Ms and UH-1Ys, and MH-60R/Ss in the attack, reconnaissance, utility and cargo missions.

Companies were invited to to give individual briefings to an Army study team at Ft Rucker last week. Bell, Boeing and Sikorsky were there, as were Lockheed Martin and Northrop Grumman. Also invited to present their ideas were Baldwin Technology, Karem Aircraft and Piasecki Aircraft. By all accounts, the smaller firms were delighted at the chance to pitch their ideas. Baldwin even produced a video of a proposed armed version of its Mono Tiltrotor.

Video: Baldwin Technology

The JMR concept has been around for a while, and it's one of very few potential new programs for a rotorcraft industry increasingly starved of research and development funding. But JMR development is not planned to get under way before 2023 at the earliest, with the initial attack version to replace Block 3 Apaches beginning in 2030 and the utility version to replace M Upgrade Black Hawks after 2038. That's a long time to wait.

The JMR industry "session" was organisation by the Concepts and Requirements Directorate (CRD) of the Army Aviation Center of Excellence at Ft Rucker. The CRD is conducting a three-phase JMR aircraft analysis study. The nine-month first phase, to be completed in September, is evaluating the feasibility of combining multiple missions in a common platform.

In the absence of specific requirements for JMR, the CRD gave industry some advisory targets: vertical takeoff and landing capability from ships and unimproved sites; 6,000ft/95ºF hot-and-high capability; cruise speed exceeding 170kt with full mission payload; 424km mission radius with 2h on station for attack/recon missions and 0.5h for utility/cargo missions; autonomous capability for optionally manned operations; plus all the usual -ilities: survivability, reliability, affordability, etc.

The goal of the CRD's study is not yet clear to me. But a parallel Pentagon-directed future vertical lift capabilities-based assessment is trying to build the case for a significant R&D investment modelled on the Joint Advanced Strike Technology (JAST) effort that preceded the Joint Strike Fighter program. Perhaps the intent here is to create a JAST-like precursor to JMR that can help industry mature the required technologies ahead of a post-2020 development launch.

http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a5d216f18-9399-4cdc-9029-68f7d4be46d9

[g4lly]

C'est un drone mais aussi un convertible ...

http-~~-//www.youtube.com/watch?v=9Lw6eQp8RsU

American drones are already lethal; so far this year, the unmanned aircraft have allegedly killed at least 365 people, in assaults on Pakistan. Now, new video of a hovering combat robo-craft shows the potential for military drones to be faster, more maneuverable - and deadlier.

The Excalibur aircraft, a 13 foot-long, 10 foot-span, half-scale test model, took an inaugural proof-of-concept flight on June 24, Aviation Week reports. Aurora Flight Sciences, the company behind the new drone, is planning a full-sized version that will carry four Hellfire missiles, at speeds of up to 400 knots. The Predator drone, by comparison, carries just two Hellfires, and cruises at just 70 knots. Unlike the Predator, the Excalibur doesn’t need a runway to take off. It just floats into the sky, thanks a titling turbojet and three battery-powered lift fans.

This isn’t the first time Aurora have created innovative models for unmanned military aircraft. For a Darpa project last year, they dreamed up a three-vehicle air machine that could dock in the stratosphere and stay aloft for five years. They’ve also worked with military researchers on micro-drones that mimic the navigational know-how of bats and bugs.

And now Aurora’s got an added boost of Pentagon expertise. Former Darpa director Anthony Tether recently joined the company’s Board of Directors.

But any military deployment is still a ways off: Aurora paid for the first flight themselves, and still plans to do several more test runs. The company’s hoping for funding to build the full-size model.

http://www.wired.com/dangerroom/2009/07/video-hovering-killer-drone-takes-flight/

[Philippe Top-Force]

On va plaisir à notre BPCelou,  :lol: en page 14 de ce dossier EADS innovation, tu découvriras que l'Europe n'est pas en reste.

http://www.ttu.fr/site/francais/frdocpdf/EADSinovation2009.pdf

Voir le projet d'Hyliner avec des rotors à ailes basculantes permettant le décollage et l'atterrissage vertical en mode hélicoptère et le vol de croisière en mode avion.  =)