From: owner-skunk-works-digest@netwrx1.com (skunk-works-digest) To: skunk-works-digest@netwrx1.com Subject: skunk-works-digest V9 #58 Reply-To: skunk-works@netwrx1.com Sender: owner-skunk-works-digest@netwrx1.com Errors-To: owner-skunk-works-digest@netwrx1.com Precedence: bulk skunk-works-digest Thursday, August 3 2000 Volume 09 : Number 058 Index of this digest by subject: *************************************************** Re: AIM-9 / F-22 question McDonnell Douglas F-15 EAGLE McDonnell Douglas F/A-18A HORNET McDonnell Douglas/BAe AV-8B HARRIER II Re: AIM-9 / F-22 Question Re: JSF and the future of aircraft manufacturers New Website: Designation Systems and Listings Re: JSF and the future of aircraft manufacturers Re: AIM-9 / F-22 Question X-Sender: jfd4288@imap RE: AIM-9 / F-22 Question SR-71 Pics Re: Meteor PR19 helicopter(technology) *************************************************** ---------------------------------------------------------------------- Date: Sun, 30 Jul 2000 20:12:02 -0700 From: "T.Toth" Subject: Re: AIM-9 / F-22 question Dan Zinngrabe wrote: > Actually, I recall seeing material that indicated that the 77 had a > much better field of view than other modern radars, extending into > the rearward aspect. > > >Although apparently provision has been made to add two extra > >antennas (if deemed > >necessary), on the sides to increase the FOV to approx. 270 deg. > >Potentially there is no limit, one could imagine having a few > >'modules' on the back, > >for 360 deg FOV greatly enhanced situation awareness, missile > >warning, jamming > >etc... ah well one can always dream I guess. > > It's been done before, and it's done on the F-22. The tail contains a > number of electronic modules. There have been test aircraft that use > almost their entire fuselage as an antenna array. > > Dan Are you talking of the F-22 when you speak of radar modules in the tail. Is this speculation, or have you seen (unclassified of course) material about this? Timothy ------------------------------ Date: Mon, 31 Jul 2000 17:57:03 -0700 From: "Terry W. Colvin" Subject: McDonnell Douglas F-15 EAGLE A new air superiority mount The F-15 was designed to succeed the same manufacturer's F-4 Phantom II, and first flew in July 1972 as a substantial twin-engined machine with advanced avionics, including a fly-by-wire control system and the very capable APG-63 radar. The type revealed phenomenal climb performance during trials, and began to enter service during January 1976. Continued development Work was already under way on an updated version with the improved APG-70 radar, a number of other electronic enhancements (including attachments for externally mounted sensor packages) and provision for FAST (Fuel and Sensor Tactical) packs. These can be attached snugly in the angle between the engine trunks and the under surfaces of the wing for considerably greater fuel capacity and additional weapon attachment points without any significant drag penalty. Production of more than 1,500 Eagles is expected. Principal versions F-15A (initial single-seat model), F-15B (initial two-seat model used for conversion and proficiency training but retaining full combat capability), F-15C (improved single-seat model with features such as more capable electronic counter-measures and provision for the new AIM-120 AMRAAM air-to-air missiles), and F-15D (improved two-seat model). Principal users Israel, Japan, Saudi Arabia, and USA. Technical data Type: McDonnell Douglas F-15C Eagle single-seat air superiority fighter with attack capability. Engines: two 23,950-lb (10,864-kg) reheated thrust Pratt & Whitney F100-P-100 turbofans. Performance: maximum speed 1,650+ mph (2,655+ km/h) or Mach 2.5+ at 36,000 ft (10,975 m); climb to 40,000 ft (12,190 m) in 1 minute 0 seconds; service ceiling 60,000 ft (18,290 m); range 2,878 miles (4,631 km) without FAST packs. Weights: empty 27,000 lb (12,247 kg); maximum take-off 68,000 lb (30,845 kg). Dimensions: span 42 ft 9.75 in (13.05 m); length 63 ft 9 in (19.43 m); height 18 ft 5.5 in (5.63 m); wing area 608.0 sq ft (56.50 m^2). Armament: one 20-mm multi-barrel cannon and up to 23,600 lb (10,705 kg) of disposable stores. - -- Terry W. Colvin, Sierra Vista, Arizona (USA) < fortean1@frontiernet.net > Home Page: < http://www.geocities.com/Area51/Stargate/8958/index.html > Sites: Fortean Times * Northwest Mysteries * Mystic's Cyberpage * TLCB * U.S. Message Text Formatting (USMTF) Program - ------------ Member: Thailand-Laos-Cambodia Brotherhood (TLCB) Mailing List TLCB Web Site: < http://www.tlc-brotherhood.org >[Allies, CIA/NSA, and Vietnam veterans welcome] Southeast Asia (SEA) service: Vietnam - Theater Telecommunications Center/HHC, 1st Aviation Brigade (Jan 71 - Aug 72) Thailand/Laos - Telecommunications Center/U.S. Army Support Thailand (USARSUPTHAI), Camp Samae San (Jan 73 - Aug 73) - Special Security/Strategic Communications - Thailand (STRATCOM - Thailand), Phu Mu (Pig Mountain) Signal Site (Aug 73 - Jan 74) ------------------------------ Date: Mon, 31 Jul 2000 18:08:58 -0700 From: "Terry W. Colvin" Subject: McDonnell Douglas F/A-18A HORNET Low-cost solution After its YF-17 had lost to the General Dynamics YF-16 in the U.S. Air Force's Light-Weight Fighter competition, Northrop teamed with McDonnel Douglas to produce a considerably revised machine designed to meet an ambitious naval requirement. This envisaged a single type to replace the McDonnell Douglas F-4 and Vought A-7 in the multi-role fighter and attack roles respectively. Changed production leadership The first example flew in November 1978 and was considerably different from the YF-17 in size, configuration and, most importantly of all, the very advanced electronics providing capability in the two apparently conflicting roles merely by software alterations. With McDonnell Douglas as prime contractor, deliveries began in 1980 for service from 1983 after a protracted development phase. Deliveries for the U.S. Navy and U.S. Marine Corps totalled 410 including two-seaters. Principal versions F/A-18A (initial dual-role fighter), F/A-18B (two seat conversion and continuation trainer retaining full combat capability), AF-18A and ATF-18A (75 land based single and two-seat models for Australia), CF-18A and CF-18B (138 land based single- and two-seat models for Canada), and EF-18A and EF-18B (75 land based single- and two-seat models for Spain). Principal users Australia, Canada, Spain, and USA. Technical data Type: McDonnell Douglas F/A-18A Hornet single-seat carrierborne and land based fighter and attack warplane. Engines: two 16,000-lb (7,257-kg) reheated thrust General Electric F404-GE-400 turbofans. Performance: maximum speed 1,188+ mph (1,912+ km/h) or Mach 1.8+ at 40,000 ft (12,190 m); initial climb rate 45,000 ft (13,715 m) per minute; service ceiling 50,000+ ft (15,240+ m) per minute; radius 662 miles (1,965 km) on a typical attack mission. Weights: empty 23,050 lb (10,455 kg); maximum take-off 49,224 lb (22,328 kg). Dimensions: span 37 ft 6 in (11.43 m); length 56 ft 0 in (17.07 m); height 15 ft 3.5 in (4.66 m); wing area 400.0 sq ft (37.16 m^2). Armament: one 20-mm multi-barrel cannon and up to 17,000 lb (7,711 kg) of disposable stores. - -- Terry W. Colvin, Sierra Vista, Arizona (USA) < fortean1@frontiernet.net > Home Page: < http://www.geocities.com/Area51/Stargate/8958/index.html > Sites: Fortean Times * Northwest Mysteries * Mystic's Cyberpage * TLCB * U.S. Message Text Formatting (USMTF) Program - ------------ Member: Thailand-Laos-Cambodia Brotherhood (TLCB) Mailing List TLCB Web Site: < http://www.tlc-brotherhood.org >[Allies, CIA/NSA, and Vietnam veterans welcome] Southeast Asia (SEA) service: Vietnam - Theater Telecommunications Center/HHC, 1st Aviation Brigade (Jan 71 - Aug 72) Thailand/Laos - Telecommunications Center/U.S. Army Support Thailand (USARSUPTHAI), Camp Samae San (Jan 73 - Aug 73) - Special Security/Strategic Communications - Thailand (STRATCOM - Thailand), Phu Mu (Pig Mountain) Signal Site (Aug 73 - Jan 74) ------------------------------ Date: Mon, 31 Jul 2000 18:21:26 -0700 From: "Terry W. Colvin" Subject: McDonnell Douglas/BAe AV-8B HARRIER II Fruitful cooperation After undertaking parallel studies for a successor to the similar Harrier GR.Mk 3 and AV-8A in service with the Royal Air Force and U.S. Marine Corps. McDonnell Douglas and British Aerospace decided to join forces for the design of an advanced version of the Harrier, and the resulting YAV-8B prototype first flew in November 1978. Much enhanced Harrier The AV-8B Harrier II entered USMC service in October 1983. By comparison with the basic Harrier, it has a more powerful engine aspirated via larger inlets, a revised fuselage with a fighter-type cockpit, a completely new and larger wing of supercritical section and graphite epoxy construction (with larger flaps, drooping ailerons, and leading-edge root extensions for improved maneuverability), better underfuselage life-improvement devices, and seven hardpoints for weapon carriage. From 1989 new aircraft have had improved night attack capability through provision of night vision goggles, a moving map display, and a head-up display accommodating FLIR imaging. Principal versions AV-8B Harrier II (production model, of which the USMC needs 328), and TAV-8B Harrier II (two-seat version with full combat capability). Principal user Spain and USA Technical data Type: McDonnell Douglas/British Aerospace AV-8B Harrier II single-seat STOVL close support warplane. Engine: one 21,450-lb (9,730-kg) thrust Rolls-Royce F402-RR-406A or from 1990 25,000-lb (11,340-kg) thrust F402-RR-408 vectored-thrust turbofan. Performance: maximum speed 661 mph (1,065 km/h) at sea level; initial climb rate 14,715 ft (4,485 m) per minute; service ceiling 50,000+ ft (15,240+ m); radius 103 miles (167 km) on a lo-lo-lo [sic] mission with a one-hour loiter. Weights: empty 13,086 lb (5,936 kg); maximum take-off 31,000 lb (14,061 kg). Dimensions: span 30 ft 4 in (9.25 m); length 46 ft 4 in (14.12 m); height 11 ft 7.75 in (3.55 m); wing area 238.7 sq ft (22.18 m^2). Armament: one 25-mm multi-barrel cannon, and up to 17,000+ lb (7,711+ kg) of disposable stores. - -- Terry W. Colvin, Sierra Vista, Arizona (USA) < fortean1@frontiernet.net > Home Page: < http://www.geocities.com/Area51/Stargate/8958/index.html > Sites: Fortean Times * Northwest Mysteries * Mystic's Cyberpage * TLCB * U.S. Message Text Formatting (USMTF) Program - ------------ Member: Thailand-Laos-Cambodia Brotherhood (TLCB) Mailing List TLCB Web Site: < http://www.tlc-brotherhood.org >[Allies, CIA/NSA, and Vietnam veterans welcome] Southeast Asia (SEA) service: Vietnam - Theater Telecommunications Center/HHC, 1st Aviation Brigade (Jan 71 - Aug 72) Thailand/Laos - Telecommunications Center/U.S. Army Support Thailand (USARSUPTHAI), Camp Samae San (Jan 73 - Aug 73) - Special Security/Strategic Communications - Thailand (STRATCOM - Thailand), Phu Mu (Pig Mountain) Signal Site (Aug 73 - Jan 74) ------------------------------ Date: Tue, 01 Aug 100 05:41:58 GMT From: betnal@ns.net Subject: Re: AIM-9 / F-22 Question On 7/30/00 7:18PM, in message <3984E1FA.D359D7F6@primus.ca>, "T.Toth" wrote: > How does the Sidewinder 'poke' it's head out? Is it lowered at an angle? or > is the > complete missile lowered out of the bay? My understanding is that the bay opens part way for the seeker head to emerge, and the missile sticks out at a slight angle. When triggered, the bay snaps open, the rail extends, the missile launches and everything closes. This happens very fast. > Of course what you say about the F-22 being in the way for acquisition by the > seeker further enhances the impression that either the missile has to have > substential 'outside' data before launch, or else it's chances of acquiring a > target are pretty small. In addition to its own searching capabilities, the AIM-9X's seeker can be cued by the radar or the HMS. However, its seeker must see the target in order to guide. > I can't imagine that the pilot would have to manoeuvre the > aircraft so that the, extended out of the bay, missile can acquire the target > by > itself, with such a limited FOV. Keep in mind there will be one -9 on each side of the aircraft, so combined, they'll have a full field of view. Also, as Sam said, USAF doesn't believe they'll ever use them. They aren't that fond of close-in or IR missiles, and could still pull out of AIM-9X, announcing they're going to buy a missile of their own. It's my understanding that the production F-23 would have carried more IR missiles than the F-22, but that didn't seem to cut any weight with USAF. Art ------------------------------ Date: Tue, 01 Aug 100 05:51:58 GMT From: betnal@ns.net Subject: Re: JSF and the future of aircraft manufacturers On 7/30/00 8:04PM, in message <3984ECD7.4E9910E6@primus.ca>, "T.Toth" wrote: > Considering the recent 'winner takes all' decision for the JSF, don't you > think that > Lockmart is at a disadvantage? After all, aren't the higher ups and > politicians > likely to decide that if they give the contract to Lockmart the future of > Boeing as > a major military manufacturer / designer is at risk, and thus all future > competition > (Lockmart already has the F-22) and no new major programs are on the horizon. > Timothy > > Boeing is a big player on the F-22, and the "plan" (of the week) is that the winner will have to provide a lot of work to the loser, although neither team has enthusiastically agreed to that. DoD keeps saying that the two teams are "neck and neck", but that shouldn't be taken as more than hype. They'll always say that. It's worthy of note that Lockheed has run into trouble with their STOVL version and needs more time. Interestingly the timeframe for the competition has been restructured for "further risk reduction" to coincide with that need. Keep in mind that on the ATF, Northrop was well ahead of Lockheed in getting their aircraft ready for first flight, when the program was suddenly slowed enough to allow Lockheed to catch up. When the final selection is made, the relative merits of the aircraft will not be that much of a deciding factor, just as they weren't with the ATF. There won't be a "Flyoff" any more than there was with the ATF. I'm not trying to reopen that or second guess the decision. This was acknowledged by the ATF organization at the time. Art ------------------------------ Date: Tue, 01 Aug 2000 09:35:52 +0200 From: Andreas Parsch Subject: New Website: Designation Systems and Listings Hi all! Ok, I KNOW that this is technically SPAM, but PLEASE read on (and see NOTE below) ... I have started a website about designations for items related to military aviation (other than aircraft), like missiles, engines, etc., at "http://www.andreas-parsch.online.de". The site is not yet complete, but available are articles about: - - Early Missiles and Drones ("http://www.andreas-parsch.online.de/old-missiles.html") - - Current Unmanned Aerospace Vehicles ("http://www.andreas-parsch.online.de/missiles.html") - - Aero Engines ("http://www.andreas-parsch.online.de/engines.html") - - Electronic Equipment ("http://www.andreas-parsch.online.de/electronics.html") NOTE: I fully realize, that this is not on-topic for the 'Skunk Works' mailing list. But because this list is read by aviation enthusiasts _only_, some of you might be interested in my website. I apologize for wasting the time and bandwidth of the others. There will be no more messages of this kind from me. Andreas Parsch Munich, Germany ------------------------------ Date: Tue, 01 Aug 2000 07:50:06 -0700 From: "T.Toth" Subject: Re: JSF and the future of aircraft manufacturers I think that politically Lockmart has an advantage because it is well represented in most allied countries, and may seem to a lot to be the normal path to follow for replacing F-16's for e.g.. This has it's importance because foreign sales would drive the price down, and there is a need to keep as much 'contact' ('influence', might seem offending to certain) with these countries a possible after all a lot of allies have had a tendency to 'wander around' lately. Off course this may not seem very objective, but I do think the Lockmart design looks much better. Timothy betnal@ns.net wrote: > On 7/30/00 8:04PM, in message <3984ECD7.4E9910E6@primus.ca>, "T.Toth" > wrote: > > > Considering the recent 'winner takes all' decision for the JSF, don't you > > think that > > Lockmart is at a disadvantage? After all, aren't the higher ups and > > politicians > > likely to decide that if they give the contract to Lockmart the future of > > Boeing as > > a major military manufacturer / designer is at risk, and thus all future > > competition > > (Lockmart already has the F-22) and no new major programs are on the horizon. > > Timothy > > > > > > Boeing is a big player on the F-22, and the "plan" (of the week) is that > the winner will have to provide a lot of work to the loser, although neither > team has enthusiastically agreed to that. DoD keeps saying that the two teams > are "neck and neck", but that shouldn't be taken as more than hype. They'll > always say that. > > It's worthy of note that Lockheed has run into trouble with their STOVL > version and needs more time. Interestingly the timeframe for the competition > has been restructured for "further risk reduction" to coincide with that need. > Keep in mind that on the ATF, Northrop was well ahead of Lockheed in getting > their aircraft ready for first flight, when the program was suddenly slowed > enough to allow Lockheed to catch up. > > When the final selection is made, the relative merits of the aircraft will > not be that much of a deciding factor, just as they weren't with the ATF. There > won't be a "Flyoff" any more than there was with the ATF. I'm not trying to > reopen that or second guess the decision. This was acknowledged by the ATF > organization at the time. > > Art ------------------------------ Date: Tue, 01 Aug 2000 08:09:21 -0700 From: "T.Toth" Subject: Re: AIM-9 / F-22 Question The fact that they purposefully neglect close-in fighting, is interesting, the UK Eurofighter team seem to have come to the same conclusion (removal of gun on UK Typhoon's to save on weight and costs). On the other hand the Russians seem to be going for a Super agile close-in fighter with their next generation design. (No-body, not even them seem to have decided yet if the S-37 is supposed to be JUST a test bed for new technology or a proof of concept design.) Even tough they have put in it all stealth they can (internal weapons, some effort on the shape/ engine inlets , RAM, etc...). And they have good long range missiles, and even better missiles waiting to be produced (ER version of R-77 for e.g.). Yet they are still emphasizing Super agility, is it just to prove a point (Russians can make good aerodynamic designs) or do they think that history will repeat itself (no guns on early F-4s)... So If the US plans not to use these misiles, what else can they put in tose bays that would prove more usefull... Timothy betnal@ns.net wrote: > On 7/30/00 7:18PM, in message <3984E1FA.D359D7F6@primus.ca>, "T.Toth" > wrote: > > > How does the Sidewinder 'poke' it's head out? Is it lowered at an angle? or > > is the > > complete missile lowered out of the bay? > > My understanding is that the bay opens part way for the seeker head to > emerge, and the missile sticks out at a slight angle. When triggered, the bay > snaps open, the rail extends, the missile launches and everything closes. This > happens very fast. > > > Of course what you say about the F-22 being in the way for acquisition by the > > seeker further enhances the impression that either the missile has to have > > substential 'outside' data before launch, or else it's chances of acquiring a > > target are pretty small. > > In addition to its own searching capabilities, the AIM-9X's seeker can be > cued by the radar or the HMS. However, its seeker must see the target in order > to guide. > > > I can't imagine that the pilot would have to manoeuvre the > > aircraft so that the, extended out of the bay, missile can acquire the target > > by > > itself, with such a limited FOV. > > Keep in mind there will be one -9 on each side of the aircraft, so > combined, they'll have a full field of view. > > Also, as Sam said, USAF doesn't believe they'll ever use them. They aren't > that fond of close-in or IR missiles, and could still pull out of AIM-9X, > announcing they're going to buy a missile of their own. It's my understanding > that the production F-23 would have carried more IR missiles than the F-22, but > that didn't seem to cut any weight with USAF. > > Art ------------------------------ Date: Tue, 01 Aug 2000 13:08:18 -0400 From: Joe Donoghue Subject: X-Sender: jfd4288@imap For those who have never heard of the British Meteor PR19 high altitude recce model. http://www.e-zine.co.nz/mmm/Meteor-PR19.HTML Joe Donoghue ------------------------------ Date: Tue, 1 Aug 2000 18:35:53 +0100 From: "Gavin Payne" Subject: RE: AIM-9 / F-22 Question I imagine we're getting to the stage where lasers and particle beam weapons will be replacing the gun. > -----Original Message----- > From: owner-skunk-works@netwrx1.com > [mailto:owner-skunk-works@netwrx1.com]On Behalf Of T.Toth > Sent: 01 August 2000 16:09 > To: skunk-works@netwrx1.com > Subject: Re: AIM-9 / F-22 Question > > > The fact that they purposefully neglect close-in fighting, is > interesting, the UK > Eurofighter team seem to have come to the same conclusion > (removal of gun on UK > Typhoon's to save on weight and costs). On the other hand the > Russians seem to be > going for a Super agile close-in fighter with their next > generation design. > (No-body, not even them seem to have decided yet if the S-37 > is supposed to be JUST > a test bed for new technology or a proof of concept design.) > Even tough they have put in it all stealth they can (internal > weapons, some effort > on the shape/ engine inlets , RAM, etc...). And they have > good long range missiles, > and even better missiles waiting to be produced (ER version > of R-77 for e.g.). Yet > they are still emphasizing Super agility, is it just to prove > a point (Russians can > make good aerodynamic designs) or do they think that history > will repeat itself (no > guns on early F-4s)... > > So If the US plans not to use these misiles, what else can > they put in tose bays > that would prove more usefull... > Timothy > > betnal@ns.net wrote: > > > On 7/30/00 7:18PM, in message > <3984E1FA.D359D7F6@primus.ca>, "T.Toth" > > wrote: > > > > > How does the Sidewinder 'poke' it's head out? Is it > lowered at an angle? or > > > is the > > > complete missile lowered out of the bay? > > > > My understanding is that the bay opens part way for the > seeker head to > > emerge, and the missile sticks out at a slight angle. When > triggered, the bay > > snaps open, the rail extends, the missile launches and > everything closes. This > > happens very fast. > > > > > Of course what you say about the F-22 being in the way > for acquisition by the > > > seeker further enhances the impression that either the > missile has to have > > > substential 'outside' data before launch, or else it's > chances of acquiring a > > > target are pretty small. > > > > In addition to its own searching capabilities, the > AIM-9X's seeker can be > > cued by the radar or the HMS. However, its seeker must see > the target in order > > to guide. > > > > > I can't imagine that the pilot would have to manoeuvre the > > > aircraft so that the, extended out of the bay, missile > can acquire the target > > > by > > > itself, with such a limited FOV. > > > > Keep in mind there will be one -9 on each side of the > aircraft, so > > combined, they'll have a full field of view. > > > > Also, as Sam said, USAF doesn't believe they'll ever > use them. They aren't > > that fond of close-in or IR missiles, and could still pull > out of AIM-9X, > > announcing they're going to buy a missile of their own. > It's my understanding > > that the production F-23 would have carried more IR > missiles than the F-22, but > > that didn't seem to cut any weight with USAF. > > > > Art > > > ------------------------------ Date: Tue, 1 Aug 2000 17:16:31 -0700 (PDT) From: David "L." Lapoff Subject: SR-71 Pics All, Some time ago someone put out a pointer to a site with SR-71 pics. One of those pics was the ramp at Beale prior to dispursing the SR-71's to various museums. I believe that there were 13 or so SR-71's shown side by side. Could someone resend a pointer to that picture. Thanks. Dave ------------------------------ Date: Wed, 02 Aug 2000 11:30:36 -0400 From: Jerry Ennis Subject: Re: Meteor PR19 On Tue, 01 Aug 2000 13:08:18 -0400, Joe Donoghue wrote: >For those who have never heard of the British Meteor PR19 high altitude=20 >recce model. >[URL snipped] The correct URL for the site is http://www.e-zine.co.nz/mmm/Meteor-PR19.HTML ***************************************************** From: Jerry Ennis (jde1@att.net) ------------------------------ Date: Thu, 03 Aug 2000 18:37:57 GMT From: "wayne binkley" Subject: helicopter(technology) from janes 04/07/00 Flights of fancy take shape BILL SWEETMAN Tomorrow's aircraft are poised to break all the rules A remarkable aircraft is being built in Victorville, California, under a contract from the Defense Advanced Research Projects Agency (DARPA). The Frontier Systems A160 unmanned helicopter is intended to demonstrate an endurance of well over 30hrs - some associated with the program are talking 48hrs or more - a service ceiling of 55,000ft (16,760m) and an unrefueled range of 3,700-5,500km. These numbers are so far beyond current helicopter records (by a factor of two or more, in many cases) that they would strain credulity, were it not for the source. The designer of the A160 is Abraham Karem. The Leading Systems Amber, which Karem designed for DARPA in the 1980s, demonstrated 28hrs+ of endurance in a small unmanned aerial vehicle (UAV), together with unparalleled reliability. Amber is the direct ancestor of today's Predator. Frontier Systems' W570 contender for the Tier 2 Plus requirement (which led to the Global Hawk), designed for Loral, was arguably more advanced in concept than the contest winner. The A160 is based on a reappraisal of the basics of helicopter design. Conventional helicopters operate within a very narrow rotor revolutions per minute (RPM) range. Their rotors are articulated to provide control authority and have flexible blades to save weight. These features lead to a complex and dynamic pattern of vibration; traditionally, rotors are designed for smooth and safe operation at a single speed point. They operate around 100% RPM whenever the helicopter is airborne. The operating RPM is usually the highest speed possible, because this reduces the difference between the speed of the advancing blade (which is moving forward into the airstream) and the retreating blade, when the helicopter is in forward flight. The upper limit (450-500rpm on a small helicopter) is set to keep the tip speed of the advancing blade in the subsonic realm - about Mach 0.6 - at the helicopter's design cruising speed. Particularly at less-than-maximum speeds and weights, however, the helicopter rotor operates much faster than necessary. This reduces the lift/drag ratio of the blades and requires more power to turn the rotor. The A160 rotor can be slowed down to as little as 40% of its maximum RPM, operating between 150-350rpm with tip speeds as low as Mach 0.25. The blades are tapered and change in thickness/chord ratio from root to tip to improve their lift/drag ratio. To avoid vibration problems, the rotor blades are light and stiff, and their stiffness in flap, lag and torsion is progressively reduced from root to tip, so that the tips are more flexible than the root. This is made possible by the use of tailored carbon fiber construction. The A160 rotor is hingeless and rigid, and has a larger diameter and lower disc loading than a conventional helicopter rotor with the same maximum lift. The result is a dramatic improvement in aerodynamic efficiency at low speeds and weights. This can be combined with a fuel-efficient engine; a key to the performance of Karem's Amber vehicles was their use of high-performance reciprocating engines, specially developed by Leading Systems. (The demonstrator has a 300kW piston engine.) The result is a helicopter with very long range and endurance, and a respectable maximum speed of 140kt. Since noise is closely linked to rotor speed, the A160 will also be exceptionally quiet. The A160 project has been under way since early 1998. Frontier Systems started by modifying a used Robinson R22 light helicopter to test the A160's autonomous flight control system software and hardware. This is designed to allow the A160 to be operated safely under the control of a non-pilot. The demonstrator was lost in an accident in February, but had flown successfully under autonomous control for 215hrs - an enviable achievement for a VTOL (vertical take-off and landing) UAV of any description. The unique A160 rotor system is now being tested on a ground rig at Victorville. The development team is anticipating some vibration problems, but modeling shows that vibration should be confined to discrete bands, leaving a well-defined operating regime which is large enough to provide good performance. The next decade should see the testing of other prototypes which break what were once considered iron-clad limits on aircraft design and performance. These include stealthy, agile aircraft with no conventional flight controls; and efficient supersonic-cruise aircraft with no sonic boom signature. Computing is the most important technology behind this renaissance in the flight sciences. Fly-by-wire (FBW) flight control systems using artificial stability were an early application of compact digital and analogue computers in the 1970s, and made it possible for the designers of the F-16 to relax the standards of natural stability that had governed aircraft design. Today, computer technology has reached the point where aircraft may be highly unstable about all axes, and the FBW system will integrate aerodynamic and propulsion control to fly the aircraft. Computational fluid dynamics Computer technology has also provided the innovative designer with valuable new tools. Computational fluid dynamics (CFD) continues to improve in its ability to model complex airflows and dynamic effects, and in the realism and resolution with which it can account for small-scale phenomena. The platforms needed to run CFD tools are becoming cheaper and more powerful. Wind tunnels and flight tests are still essential, but CFD allows more designs to be explored and developed in detail at far less cost than tunnel testing. When it comes to building prototypes, information technology helps combine speed and low cost with high quality. Computer-aided design and manufacture, as demonstrated by the Boeing Phantom Works in a number of prototype programs (including the X-32 and X-36), makes it possible to proceed quickly on a prototype program without giving it a top-priority status that disrupts other work. Burt Rutan's Scaled Composites operation has also demonstrated the ability to produce aerodynamic demonstrators at short notice. (The newest Scaled prototype, the Adam M309 twin-engined light aircraft, was flown less than 10 months after contract award.) Less expensive unmanned prototypes are also becoming more routine. Information technology provides more efficient datalinks and smarter control systems, often based on cheap commercial hardware. Unmanned prototypes are less expensive to build than piloted vehicles, and can usually be more faithful to the full-scale design. Except in the case of a large aircraft, the need to accommodate a crew station makes it difficult to produce a high-fidelity manned subscale prototype. Rapid communications and integrated product teams (IPTs) have generally led to improved program management. Some of the Pentagon's Advanced Concept Technology Demonstration (ACTD) projects, such as the Global Hawk UAV, have produced positive results. What is equally important is that, where ACTDs have been less successful (as in the case of DarkStar), they have been completed within reasonable time and cost limits. There have been no recent programs comparable to the X-Wing, the X-29 or F-15 STOL/Maneuver Technology Demonstrator, each of which took several years, cost more than US$100 million and demonstrated technologies that the industry was not interested in exploiting. Restrained costs and more consistent results have encouraged customers to fund more demonstration programs. Since 1990, NASA and the USAF (United States Air Force) have assigned more new X-vehicle designations than they did in the previous 30 years, and the Tactical Technology Office of DARPA has also sponsored several prototype programs. NASA, the armed services and DARPA are working together as never before. NASA's alignment with the USAF and National Reconnaissance Office on space research is being replicated in air-vehicle programs, particularly when they have military and commercial applications. The latest batch of NASA Revolutionary Concepts (Revcon) programs include one project which meshes closely with a DARPA effort, and another which is based on an operational vehicle concept devised by the USAF Research Laboratory. Canard Rotor Wing The A160 is one of two DARPA-funded demonstrator programs that are well into the hardware stage and which are aimed at increasing the performance envelope for vertical-take-off aircraft. The DARPA/Boeing Canard Rotor-Wing (CRW) demonstrator is being completed at Mesa, and should fly early next year. The CRW combines two long-standing concepts - the hot-cycle tip-jet helicopter and the stopped-rotor helicopter - with the newer idea of a three-surface fixed-wing aircraft. The 1,100kg-class demonstrator is powered by a low-bypass-ratio Williams International F112 engine (as developed for the AGM-129 Advanced Cruise Missile). For take-off, the exhaust is ducted via titanium pipes to nozzles on the tips of the two-blade rotor. The rotor has a simple gimballed hub, and cyclic and collective blade pitch control. No anti-torque rotor is needed, but small thrust nozzles on the rear fuselage are used for directional control. The CRW accelerates to 60kt like a conventional helicopter, with all the exhaust going through the rotor. Transition takes place between 60kt and 120kt. During transition, the exhaust is switched to a conventional nozzle. Flaperons on the canard and tail surfaces are deflected downwards to lift the vehicle and unload the rotor. The gimbal freedom of the hub is gradually reduced by variable dampers. At 120kt, the rotor is entirely unloaded. The hub and pitch hinges are locked in the flight position and the flaperons move upwards, transferring most of the lift back to the wing. The main advantage of the CRW, compared with earlier stopped-rotor concepts such as the X-Wing, is that it has a simple helicopter configuration (with no tail rotor) and a simple fixed-wing configuration, with the canard- and tail-borne mode to smooth the transition between the two. The rotor is also a pure lifting device - all the thrust is provided by the turbofan exhaust. The CRW is scalable in size and performance, according to Boeing. It is simple enough to be a practical solution for a 2-2.5 tonne UAV. Its speed can be increased into the high-subsonic regime by stopping the rotor-wing in a skewed position. Also, reaction-drive helicopters actually become more attractive at large sizes. The transmission of a normal helicopter is sized by torque - which increases rapidly with rotor size, because the power increases and the rotational speed declines. Boeing has looked at a CRW attack aircraft in the 11 tonne range, as well as at some transport applications. There are some inherent design penalties in the CRW. The disk loading is at the upper end of the helicopter range - around 12-15 lbs/ft2, in the same order as the CH-53E. This could be a problem in operations that require hovering (rescue or ASW with a dipping sonar, for example) although it would not impede operations from unprepared surfaces. The low-bypass-ratio engine cycle is not ideal for subsonic cruise, particularly at low altitude, and the symmetrical aerofoil section is also a compromise, because it must develop lift in either direction. However, the CRW's combination of jet speed and helicopter-like vertical lift efficiency is unique. ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com ------------------------------ End of skunk-works-digest V9 #58 ******************************** To subscribe to skunk-works-digest, send the command: subscribe in the body of a message to "majordomo@netwrx1.com". If you want to subscribe something other than the account the mail is coming from, such as a local redistribution list, then append that address to the "subscribe" command; for example, to subscribe "local-skunk-works": subscribe local-skunk-works@your.domain.net To unsubscribe, send mail to the same address, with the command: unsubscribe in the body. Administrative requests, problems, and other non-list mail can be sent to georgek@netwrx1.com. 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