mabieThat’s one HUGE pod!
mabieArent they thinking about a new Surveilance unmanned aircraft ??
Maybe something based on hydrogen fuel and a 10-day endurance?
Boeing working on new large UAV
By Bill Sweetman IDR Aerospace and Technology Editor
Minneapolis
Boeing and a team of partners have been working for more than two years on a large, hydrogen-fuelled, high-altitude, long-endurance (HALE) unmanned aerial vehicle (UAV), according to George Muellner, president of advanced systems for the company’s Integrated Defense Systems unit.
“We are almost ready to build a full-scale prototype and could take a decision in the next six months,” he said.
The major thrusts of the new programme have been to develop lightweight insulated liquid hydrogen (LH2) tankage – work that Boeing has been carrying out under contract to the US Air Force Research Laboratory – and an LH2-fuelled propulsion system.
The new UAV would have a 10-day endurance, which Muellner said will “gain the majority of benefits in fleet size”. The 10-day endurance makes it possible to maintain non-stop coverage at a substantial range with two vehicles. It would be similar in size to Boeing’s 61 m-span Condor UAV, built in the 1980s.
mabieThe Europeans see a definite value to a reduced RCS.. it appears though that they are unwilling to spend the necessary billions and years of R&D time to achieve the miniscule RCS levels attained by the US. Thus combining a reduced RCS supplemented by electronics is a cost-effective compromise in their minds. Bit I don’t doubt for a minute that if the costs were more affordable, they’d emulate the Americans.
mabieThe termination of the Tier 3- ACTD had more to do with fundamental design issues (primarily aerodynamic instability and inadequate performance), plus cost and schedule overruns. The program was already going heavily over-budget — primarily due to overoptimistic assumptions over the ability to use the FCS software from the Tier 3 program — when the crash of the first prototype resulted in further redesign costs and delays.
It’s probably fair to say that the RQ-1/MQ-9 have exceeded their initial expectations, but the Predator platform is still very much limited to operations in low and moderate risk environments.
Thanks, good info to know. i was curious why they didn’t just scale up DS to get a similar range and payload as GH but apparently they had good reason to terminate the program.
This does seem to leave a gap in recon capabilities over hostile territory.
mabieTier 2 (Global Hawk) and tier 3 (Darkstar) had different design requirements and are not comparable.
Tier 2 is intended to be an extremely long duration (24+ hour), high flier to collect strategic intelligence. The idea is to fly near the enemy’s borders and use extreme altitude to look deep into his territory. A high degree of stealth is not required since Tier 2 never penetrates enemy airspace. A long range SAM or interceptor would be bad news for a Global Hawk because it doesn’t have the situational awareness, ECM, speed or altitude to escape.
Tier 3 was intended to be a medium duration (<12 hour), medium altitude flier to collect battlefield intelligence. The idea was to overfly the battlefield. This sortie profile requires stealth to avoid the attention of enemy SAM batteries.
So is it more accurate to compare DarkStar with Predator? Did Predator make DS redundant?
mabieI’d sign a mutual deffense treaty with a couple of the big democracies as my first step. This will buy me the time needed to set up my defenses. O like the idea of buying a plug and play SAM system as one of the first steps.
mabieErrr… this isn’t new, and is implimented on the F-16 as well as the new Su-35KUB.
It is simply changing the shape of the wing with control surfaces. Think of a trail edge flap that is lowered to increase the curve of the wing and therefore increase both lift and drag. Put another flap on the front of the wing and you can change from a thin flat low drag low lift surface to a high lift high drag surface. There is no wing morphing involved.
The MAW concept did away completely with control surfaces. The wing could flex in lieu of having flaps and slats.
mabieThe original MAW concept, as flown on the F-111, was about infinitely variable airfoil chamber from high lift/high chamber to high speed/no chamber. Trade studies have not found MAW to have sugnificant benefits over tradtional leading edge flap/trailing edge flap airfoils.
Yes, the LMA approach is definitely different from Boeings’s original concept.
mabieComparable in terms of what?? It could just be that it is comparable in purpose,specs,mission or something other then capability.
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DOD seemed to offer a re-assessment of the capabilities of China’s F-10 fighter……,
Comparable in terms of capabilities.. its a big jump to upgrade the F-10’s capabilities from F-16C blk30 to EF/Rafale class, and I just wanted opinions if this is an accurate assessment or not.
mabieDARPA/DOD are working on a program called MORPHING WING program meant to prove the technology and provide a test bed and a demonstrator of technology which is combat friendly. LMA has come out with a vehicle that demonstrates this capability. A limited capability aircraft will fly late this year.
http://www.afrlhorizons.com/Briefs/Jun05/VAH0502.html
http://www.freerepublic.com/focus/f-news/1427182/posts
http://www.athenati.com/case_studies_videos/case_studies/morphing_uav_2
Thanks, that’s precisely what I wanted to know. The technology has evolved somewhat from the original but its nice to know the MAW concept wasn’t relegated to some dusty filing cabinet.
mabieBut as I said… and apparently you misunderstood… such a wing would be much heavier than a conventional wing structure, thus reducing useable payload.
It would also be (having many moving parts) a significant source of malfunctions, which would reduce its effectiveness in combat and greatly increase maintenance hours (reducing availability and increasing logistics support requirements… more cargo flights).
It would also be much more susceptable to battle damage than a simpler, stronger conventional structure. This would be very bad for a combat aircraft, right?
One more problem… much of a modern fighter’s fuel is carried in its wing structures, and this concept would use up a lot of that volume for the shape-altering equipment… which would significantly reduce the aircraft’s range.
4 very good reasons this is not a good idea for a combat aircraft, and you still think that some kind of conspiracy is involved in keeping this from being used?
Would love to see any sources for your opinions re disadvantages of the MAW. On the surface, what you say appear to make sense. I just want to get something maybe from Boeing who conducted the MAW tests that it wasn’t practical or feasible because all writeup I’ve seen have been positive.
mabiewhile I don’t think anyone could produce a ‘magic’ wing that changes cross-section etc., If I remember correctly, NASA DID work on prototype ‘flex-wings’ on an F/A-18 (and perhaps even an F-8 and F-111) in which the ‘conventional’ control surfaces were eliminated and the entire wing was twisted to induce changes in direction… harkening back to the Wright brothers.
While I believe the tests were successful, one does have to wonder how much use the wings would be for the carriage of ordnance.
Not magic definitely but definitely more efficient and versatile and the concept of a flexible wing was proved to work on a F-111. As I understand it, only the upper surface of the wing was flexed, not the bottom so external carriage would be unaffected, not to mention any weapons carried internally as in the latest generation of stealth fighters.
mabieUmmmmm…. weight? reliability? vulnerability to battle damage?
That’s just it.. either the aviation industry has no intererst or maybe something’s going on behind people’s backs. The only references I’ve seen since then are in a couple of techno-thrillers.. maybe they’re hidden away somewhere in Area-51?
mabieNope, swing wing is variable geometry (movable wings i.e. Su-24, F-111, Mig23/27). Mission adaptive wing does away with slats and flaps and changed the cross-section (leading and trailing edge curvature) of the wing.
This wing had an internal mechanism to flex the outer wing skin and produce a high camber section for subsonic speeds, a supercritical section for transonic speeds, and symmetrical section for supersonic speeds. The surface irregularities from leading edge slates was eliminated and trailing edge flap effects reduced. The use of flexible wing skins to produce a smooth upper surface brought this wing a little closer in concept to that of a bird. A digital flight control system provided automatic changes to the wing geometry. The system had four automatic control modes: (1) Maneuver Camber Control – adjusting camber shape for peak aerodynamic efficiency; (2) Cruise Camber Control – for maximum speed at any altitude and power setting; (3) Maneuver Load Control – providing the highest possible aircraft load factor (4) Maneuver Enhancement Alleviation – in part attempting to reduce the effects of gusts on airplane ride. The AFTI/F-111 MAW system had 59 flights from 1985 through 1988. The flight test data showed a drag reduction of around 7 percent at the wing design cruise point to over 20 percent at an off-design condition. The four automatic modes were tested in flight with satisfactory results….
Based on the above excerpt, the idea seemed to work. Hopefully, it will findits way onto some production aircraft in the future.
mabieI thinkTaiwan has the money and the need for F-22s however there’s always the risk of a ROC pilot defecting to the mainland. South Korea is another possible candidate with the money and a very real threat. But japan is top of the list IMO.
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