International Aerospace Discussion

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deejay
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Re: International Aerospace Discussion

Postby deejay » 10 Feb 2015 09:23

^^^@Lisa great video. Thanx.

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Re: International Aerospace Discussion

Postby member_20067 » 10 Feb 2015 23:08



first flight of Embraer KC- 390 freighter------ the level of marketing spend on visual, production is quite impressive--- and our DRDO folks need to learn a lot from these guys on how to market a product--- our product brochure and videos still feel like from 80s

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Re: International Aerospace Discussion

Postby srai » 11 Feb 2015 04:23

^^^

Where is the Indo-Russian MTA???

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Re: International Aerospace Discussion

Postby Leo.Davidson » 11 Feb 2015 08:12

The MTA is being designed and built at Severodvinsk along the lines of the INS Vikramaditya delivery.

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Re: International Aerospace Discussion

Postby Austin » 11 Feb 2015 10:54

Iran unveils indigenous supersonic fighter jet

Image
Iran's Defense Ministry has unveiled a new domestically-built advanced supersonic trainer fighter jet, named Saeqeh 2 (Thunderbolt 2).

The double-cockpit supersonic Saeqeh 2 fighter jet has been designed and manufactured by experts and engineers of Defense Ministry's Aerospace Industries Organization and in cooperation with the Islamic Republic of Iran Air Force (IRIAF), Iran's Deputy Defense Minister Brigadier General Amir Hatami said on Monday.

The fighter jet will do close-range cover and backup tactical missions as well as advanced pilot training missions, he added.

The commander noted that the new jet is the second generation of Saeqeh model which has been manufactured with enhanced combat capabilities.

The aircraft has been equipped with Electro Avionics systems and advanced weapons to enhance the training of pilots.

Hatami added that the plane is capable of engaging in intense aerial missions.

The unveiling ceremony comes on the 8th day of the ten-day celebrations commemorating the 36th anniversary of the victory of the Islamic Revolution in 1979.

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Re: International Aerospace Discussion

Postby Shreeman » 11 Feb 2015 10:59

^^^ There are pictures of a squadron or two of saeq-1 and 2 on the net. admirable achievement for iran.

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Re: International Aerospace Discussion

Postby brar_w » 11 Feb 2015 23:31

Seoul forced to re-tender KFX bidding



Seoul has been forced to re-tender its bid for a developmental contract related to the country’s KFX fighter aircraft programme.


Since only one bidder, Korea Aerospace Industries (KAI), showed up to submit a bid on Monday 9 February, procurement laws have forced a retendering of the programme, says a report by state news agency Yonhap.

On 10 February, the country’s Defence Acquisition Procurement Agency (DAPA) posted the new tender for the KRW8.5 trillion ($8.3 billion) programme, which is to run from 2015 to 2025. The deadline for bidding has been pushed back to 24 February 2015.

The KFX is envisaged as a two-engined fighter that is more advanced than the Lockheed Martin F-16, but not up to the standard of types such as the F-35 Lightning II. It will replace obsolescent types in the Korean air force’s inventory, namely the McDonnell Douglas F-4 Phantom and Northrop F-5.

KAI would partner with Lockheed Martin on the project, in which the Indonesian government has a 20% share. Seoul is expected to order 120 examples of the KFX, and Indonesia 80. Media reports indicate that the other likely bidder will be Korean Air through a partnership with Airbus Defence & Space. Although Airbus is primarily concerned with larger types such as the A400M tactical transport and A330 multi-role tanker transport (MRTT), it has a 46% shareholding in the Eurofighter Consortium.

The Eurofighter Typhoon was a failed bidder for Seoul’s F-X III competition, which was ultimately won by the F-35 in late 2013. The other failed bidder was Boeing’s F-15 Silent Eagle.

A hallmark of the intense – and often acrimonious - F-X III competition was the degree of industrial cooperation rival bidders were willing to offer in relation to KFX.

Both KAI and Korean Air have strong defence backgrounds, but KAI has more experience in developing and manufacturing fighter aircraft. Apart from collaborating with Lockheed to develop the T-50 family of trainer/light attack jets, it also produces the forward fuselage of the F-15, and has been involved in the manufacturing and re-manufacturing of other military types.

Korean Air, for its part, provides extensive MRO services for military aircraft at its Pusan facility.

In late 2014, Indonesia’s defence ministry said that Jakarta had signed an agreement with Seoul that set the stage for KFX to move into the “engineering and manufacturing phase” – the second of the programme’s three phases.

The statement said the first phase, which covered technology development, was completed in December 2012. The third and final phase of the programme covers the development of production capabilities.

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Re: International Aerospace Discussion

Postby member_23370 » 11 Feb 2015 23:52

Shreeman wrote:^^^ There are pictures of a squadron or two of saeq-1 and 2 on the net. admirable achievement for iran.


Well luckily for them they don't have to deal with IAF, who would have asked for photon torpedo's and cloaking capabilities on it. :(( :lol:

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Re: International Aerospace Discussion

Postby Khalsa » 12 Feb 2015 00:21

Bheeshma wrote:
Shreeman wrote:^^^ There are pictures of a squadron or two of saeq-1 and 2 on the net. admirable achievement for iran.


Well luckily for them they don't have to deal with IAF, who would have asked for photon torpedo's and cloaking capabilities on it. :(( :lol:


Engineering .... divert all power to the front deflector shield
:rotfl: :rotfl: :rotfl:

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Re: International Aerospace Discussion

Postby member_28756 » 12 Feb 2015 21:52

http://aviationweek.com/commercial-avia ... n-underway

Russo-Chinese Widebody Concept Design Underway
Full-scale development of a Russo-Chinese widebody may begin next year
Feb 11, 2015 Maxim Pyadushkin and Bradley Perrett | Aviation Week & Space Technology

Widebody Duo

Russia’s United Aircraft Corp. (UAC) and China’s Comac have begun preliminary design of their proposed joint 250-280-seat widebody airliner, which Moscow now expects to enter service in 2025. This phase should be completed by July, says UAC President Yury Slyusar, while Industry and Trade Minister Denis Manturov suggests that full-scale development will begin next year.

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Re: International Aerospace Discussion

Postby brar_w » 13 Feb 2015 02:46

Lockheed Martin debuted a new pod today at the AFA Air Warfare Symposium. The Legion pod is meant for legacy fighters and combines the IRST-21 (a follow up to the F-14D IRST system, with inputs from the classified F-22 IRST R&D) with new waveforms that allow the legacy jets to share Situational Awareness data among each other outside of the Link-16 chain. This is most likely a competitor to the Talon Hate pod developed by Boeing that is meant to link F-15's, F-16's to F-22's for a SA picture transfer.

Image
Image

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Re: International Aerospace Discussion

Postby Cosmo_R » 13 Feb 2015 02:51

@Khalsa ^^^ Scotty to Kirk: " I'll do my best suuur, but the the dilithium crrrystaals are breakin' aparrrrt Capn'

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Re: International Aerospace Discussion

Postby Cosmo_R » 13 Feb 2015 02:55

Iran and the saeq-1 and 2. They sure look like reworked F5Es with twin tails. Iran got a lot of the F5Es

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Re: International Aerospace Discussion

Postby Cosmo_R » 13 Feb 2015 03:07

Re Embraer ^^^ privatized in 1994 but the Brazilian government retains interest through possession of golden shares, which allow it veto power.

http://en.wikipedia.org/wiki/Embraer

I made this point about Class A/B shares vs looking at percentage ownership. Mark Zuckerberg's shares have a 10x voting right so unless he has less than 10% of shares outstanding, he has total veto power. In our context, we can have defence FDI of 90% but with golden or Class B shares, we have voting control.

I am still surprised how slow the Modi govt have been on the uptake on this. At 90% ownership, Boeing, LM, Raytheon, NG will all be breaking down the door to get in. Profit sharing and voting rights can be two different things.

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Re: International Aerospace Discussion

Postby brar_w » 13 Feb 2015 03:44

GE Graphic from ADVENT to AETD transition. ADVENT has finished, AETD would continue till 2016 at which time the two engines would be tested and then the USAF would transition into yet another program (AETP).

Image

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Re: International Aerospace Discussion

Postby Singha » 13 Feb 2015 07:29

the legion pod thing + link16 + network warfare concepts sounds something similar the Saab Wiscom thing

http://aviationweek.com/awin/saab-takes ... evelopment

Saab has unveiled its concept of “wide spectrum combat” (Wiscom) to exploit the potential of the next-generation JAS 39E/F and C/D Plus, the latter being a C/D retrofitted with E/F avionics and sensors.

One part of the Wiscom concept is the idea of a “flexible antenna pool” in which all aircraft in a flight share sensor and target data automatically. Another is “silent swarm ingress” where a flight enters combat in a widely dispersed pattern, with primary sensors being infrared search and track (IRST), active, electronically scanned array (AESA) radars operating in passive mode, and electronic surveillance measures (ESM).

Under Wiscom, AESA transmissions are restricted and “random”—that is, the aircraft in a flight will transmit at different times, making it difficult to track them by emissions. Swedish engineers have noted that data-linked radars can share plots—not just tracks—and take simultaneous range-rate measurements, allowing two radars to determine a target's velocity almost instantly. Finally, Saab envisages the use of the high-energy MBDA Meteor air-to-air missile to engage from side and rear aspects where targets are less likely to detect the threat.

For air-to-surface missions, Saab is studying an improved RBS 15ER (extended range) version of its own cruise missile with improved land-attack capability. In maritime attack, Wiscom tactics would allow a flight of Gripens to assess the target formation and launch up to two missiles each from different directions with simultaneous arrival times, saturating the target's ability to defend itself.

While other fighter programs claim the ability to use real-time networked tactics, Wiscom is not entirely new, but an extension of Swedish technology developed since the 1960s, when data links were introduced secretly to bypass Soviet communications jamming. The first two-way aircraft-to-aircraft fighter link was deployed on the JA 37 Viggen in the 1980s. It was disclosed after the Viggen was retired in 2005 that it was capable of a “silent” AIM-120 Advanced Medium Range Air-to-Air Missile attack, performed by two aircraft using their PS 46/A radars in passive mode.

The original Tactical Information Data Link System (Tidls) fitted to the JAS 39A/B was designed to display the position, bearing and speed of all four aircraft in a formation, including basic status information such as fuel and weapons status. Tidls information, along with radar, EW and mapping data, appears on the central multi-function display. Detailed symbols distinguish between friendlies, hostiles and unidentified targets and show which member of the flight has targeted each hostile. Wiscom blends this capability with AESA, IRST and improved electronic support measures.

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Re: International Aerospace Discussion

Postby Singha » 13 Feb 2015 07:30

Massa's east pacific plans of sending F22s ahead in passive mode and using big aperture APG63vX type F-15 radars and E-3s in the back to provide silent targeting data to the raptors is something similar. in due course UvLO supersonic Ucavs armed with 6-8 AAMs might be the only "shooters" in an area, with the surveillance platforms deep in the rear and acting as pointer dogs towards targets. reduces risk to pilots considerably and permits much higher-G loads on the ucavs.

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Re: International Aerospace Discussion

Postby brar_w » 13 Feb 2015 08:24

Its called a Combat Cloud :)


The concept dates back to ATF days (which really means late 70's to early 80's, when air superiority was being discussed and the initial ground work was being laid for the concept that would eventually evolve into the Advanced Tactical fighter program). Ever since the ACC got a hold of the F-22 (Early 2000's) they have been promoting the concept that the F-22 be the " last shooter in offensive enterprise (use target and find capability), and be the first shooter in defensive mode. This was laid out during General Jumper's time and was re-stated by the now retired Secretary Wynn who was at the helm at different key positions during some of these programs. The reason is simple, the F-22 is stealthy and can penetrate deeper into the adversaries defenses then any other fast jet platform at the USAF's disposal. Therefore, they advocated that the F-22 stay there while providing the SA to all the forces behind the " Forward Edge of Battle-space". The distributed sensor approach is the corner stone of the F-35 and JSF avionics and systems approach and something that has taken painstakingly long to execute. The USN's tactics emerging even at the nascent stage of it "exploring the possibilities" of the F-35C point to the weapon being a distributed sensor in the offensive role, much like the F-22 is to the USAF in that scenario.

See: http://news.usni.org/2013/12/31/f-35c-w ... ears-fleet

Distributed sensors was also the basic underlying concept of the F-22/ATF. The ATF had two-mission sets. One was the European mission where you had a relatively known radius and you knew the threat and what assets would require to cooperate. For the stealth fleet it was the F-117, F-22 and B-2. No other cooperation was required because it at the time would have compromised EMCON. SA was built up through the distributed network while exercising the maximum signature restrain (RF emissions or EMCON). In the Pacific they were to counter subsonic soviet bombers therefore required the assets to be spread out, high up in intercept mode. Here they wanted the 120+60 degrees RF radar with 120 degrees through the nose (side lobes as the PAKFA is doing now) and the other from X-Band AESA TR Modules embedded in the wings. Originally the plan was to have 180 IRST coverage with 2 distinct sensors in the wings (later changed to the nose). These features were dropped from the ATF post SU collapse because the bomber threat from the Pacific was no longer a major concern and the high end European threat warranted Emission restraint and not blasting away RF emissions all around the aircraft. You can also not make everything LPI especially if you cannot control the directionality or are emitting in all directions. Therefore distributed SA became the cornerstone of strategy going forward (into the F-35 program and beyond).

The concept of multiple waveforms (you cannot communicate with just the L-16 for many reasons, unlike the Gripen that is not required to operate along-side stealthy assets and strategic bombers for whom EMCON is of the utmost importance) also originated over a decade back and was known as the Tower of Babel Concept where an appropriate waveform is provided to an appropriate assets. For example, the F-22 talks to other F-22's using the IFDL, talks to other F-35's using the MADL (Now dropped) or by using the L-Band sensors that the two aircraft share (the current plan). The F-22 listens to the F-15's, F-16's, and F-18's using Link-16 and eventually communicates to them using a different waveform that takes the IFDL and converts it into L-16. This capability was recently tested by Boeing under project Talon Hate - the aim being to translate an LPI/LPD waveform to a less survivable waveform as you move back from the forward-edge of battle-space. Talon Hate is going to be operational with ACC's F-15C's in June of this year. Lockheed had also demo'd its solution for 4th to 5th and 5th to 5th, under Project Missouri... and this is obviously one product that spun off and would eventually compete with the Boeing pod that itself uses Lockheed's IRST. The USAF has been engaged in stealth for decades. There is a reason why the now Retired General Hostage, head of ACC at the time was adamant that he does not want a Growler anywhere near his F-35 fleet. Stealth assets cannot rely on RCS alone for if you are broadcasting/emitting or being accompanied by an asset that is, your millions spent on reducing signature are a waste. These aircraft employ other means to achieve EW/EA and defeat air-defenses.

Throughout the ATF lockheed was given tens of millions of dollars to develop the F-22's IRST, and they collaborated with partners such as General Electric to advance IRST research. Meanwhile, they secured USN funding to develop a modern IRST for the F-14 that they were considering that eventually lost to the F-18E/F. Lockheed also had tremendous work developing algorithms for the EOTS and have spun that into the IRST-21 product line that they are now marketing. The IRST-21 was used by Boeing, put on a centerline tank and will soon enter LRIP for the USN's F-18E/F. This current pod uses the same IRST-21 but is a different concept given the function demanded.

The reason why this is mentioned less in articles in the media is that the ACC has the authority to execute these sort of things on their own without going through the regular routine project. So the ACC (Air-Combat-Command) can ask Boeing and Lockheed to quietly come into Langley, and develop a pod that does this. There is no outright competition that the media can latch on to because they have liberty to do this without making too much noise. All the development is present in the DOD budget, under line items and some in the media that "know their stuff" have latched on to this and reported it from time to time. Stephen Trimble comes to mind straight away. Some paid/subscription articles form Janes have also done a fine job.

Another area that gets less attention is that of Air-2-Air missiles. Prima facie it would appear that USAF and Raytheon are quietly surrendering the market to Europe and the Meteor. This however is hardly true. The Triple target terminator was quietly testing 2 brand new clean sheet missile designs in 2013 (check the appropriate thread on secret-projects website) both involving a solid fueled variable ducted ramjet that Aerojet was the first in the world to operationalize (Coyote missile). In addition to this DARPA has an active program under SACM initiative of which Lockheed has already shown the CUDA concept. This is quietly being funded but much like the current X-Plane program for 6th generation fighter - the line items are kept classified in the DARPA budget (under Air dominance Initiative). In WEST 2014 the F-35C pilot was asked about the AMRAAM by reporters to which he quietly replied that he is at no liberty to talk about what activities are happening in that area. That wasn't reported, what was reported by the media was the lockheed's test pilot's claims that a new longer ranged missile is required (talk about cherry picking quotes).

The problem with SAAB's approach is that VLO fighters (at least the F-22 and F-35) exercise extreme EMCON, and have had decades of R&D and operational experience behind them in being quiet and exercising restraint as far as broadcasting their position by emitting. Both these also employ LPI/LPD directional data-links. If you do not know where the heck a VLO asset is you would literally be a kid with a flash-light in the dark looking around. You can do all the zig-zag flying, and intermittent emission but you need to broadcast and the EW suites here are no slouches..The F-22 has 30 Embedded antennas and the F-35 around a dozen. Moreover you are not looking for a one off F-35 or F-22 flying somewhere in the open sky but are looking at multiple ones that can quietly share their EW/EA data and geolocate emitting threats. Throw in the F-35 to the mix and you can cover the IR dommain as well. There is a reason why the F-35 has forced the competition going forward to adopt stealth, internal weapons bays etc into designs. The capability has to proliferate because the asymmetrical advantage is significant especially if this comes at a cost that is not too dissimilar to advanced 4.5 generation aircraft. The SA' generating ability of the F-22 and F-35 has forced the USAF to change Red-Flag and move it towards the Live-Virtual construct because of the range limitations and how hard it is in real-life to fool the sensor-fusion with threats. Simply put these sensors can see for heck of a long distance passively, and since the fusion is being done by the ICP, its tough to confuse, overwhelm or deceive it in a live setting unlike the legacy pilot and WSO where you can throw in wrenches into the SA by flooding the sky with emissions, ad other threats that they'd have to put together and prioritize.

Two white papers of relevance :

http://www.sldinfo.com/the-next-phase-o ... bat-cloud/

http://www.sldinfo.com/training-for-the ... ing-range/
Last edited by brar_w on 13 Feb 2015 20:30, edited 7 times in total.

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Re: International Aerospace Discussion

Postby Karan M » 13 Feb 2015 09:59

brar_w wrote:Lockheed Martin debuted a new pod today at the AFA Air Warfare Symposium. The Legion pod is meant for legacy fighters and combines the IRST-21 (a follow up to the F-14D IRST system, with inputs from the classified F-22 IRST R&D) with new waveforms that allow the legacy jets to share Situational Awareness data among each other outside of the Link-16 chain. This is most likely a competitor to the Talon Hate pod developed by Boeing that is meant to link F-15's, F-16's to F-22's for a SA picture transfer.

Image
Image


Pretty much shows that with DRFM & SSTx tech available in a pricey market, radars plus IRST is the way forward.

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Re: International Aerospace Discussion

Postby brar_w » 13 Feb 2015 10:06

IRST has a role but unfortunately the role from F-15 and F-16's would be limited due to the computing power and a lack of integrated avionics. The F-22 can get an IRST but that would most likely be post alignment of its mission systems and ICP's with the F-35 which would take a while. The sensor tech is less of an issue with IRST's in general (especially the advanced ones). The real deal is in computing, algorithms and how a collective group of integrated sensors can be used together to manage false alarms. Furthermore advances in both EODAS and IRST type sensors are often limited by computing power and algorithms and software footprint and not by sensor quality. The reason why these sensors won't be changed as often as new technology is available (think higher resolution) is because the limiting factor would be the computing and sensor-fusion engine (and possibly packaging) and not the quality of the sensor itself. Lockheed has already hinted at some unique GMT applications of its IRST sensor on the F-35, but that is based on a trajectory of growth in the mission computers that get upgraded every other block.

Radar is still the king but it hasnt performed independently for a while now. The EA/EW suite, coupled with a powerful Integrated SA suite that combines data from various platforms is ultimately the enabler of high quality SA. Not to mention that it is damn hard to deny compared to a sole radar operating in a bubble. Looking into the future all weapons development is concentrating on updated RF seekers as well be it the Japanese-UK Meteor development or the Lockheed Martin CUDA (RF seeker) or the Russian weapons. Even multi-mode seekers would have the RF seeker as the dominant feature. The commodity is "information" and that is what is driving modern combat designs and ultimately the cost. For 4th gen more than 70% of the cost was made up of Airframe and Propulsion with 10% going into testing and evaluation. For the Fifth gen Avionics consume around 40% of the development cost and this would likely go up with 6th generation products.

The current Legion pod being developed (should fly by March-April according to defetnsenews) can switch between the IRST-21 sensor upfront or a specialized RF sensor. This opens the door for various cross-domain tasks. Strap on an emitting waveform upfront and you can at a short notice send USAF F_15C's, E's and F-16's to enter the USN's NIFC-CA network to assist them. Also you could potentially take elements from the EA-18G passive RF suite and provide a sensor for targeting radiating threats and develop a very low cost DEAD platform. What the back end of this pod allows users to do is mix the sensor load. No need for a one to one procurement of the IRST sensor version of the pod. You could send a four ship with 2 aircraft with the IRST mounted Legion and perhaps the other two with some other sensor. Because the processing and SA sharing takes place from within the pod (not through expensive retrofits and upgrades to the user aircraft) each aircraft that carries the waveform back end gets the tactical picture updated through each other's pods. This has significant export potential and I see the IDF jumping all over this in the relative near term. The open architecture allows them to be easily configured. So if an operator buys 2 dozen, they can rapidly and on the fly shift them from tactical fighter platforms to something that has a longer loiter time or TOS (such as a UAV for example, or a Battle management aircraft) without seeking a new version of the pod for that application. Clearly the design of this system has been driven by airmen over at ACC that take the lead in charting " wish to have" systems to the industry. A neat, low cost solution to a host of challenges that tactical and strategic forces are likely to encounter.
Last edited by brar_w on 14 Feb 2015 00:01, edited 2 times in total.

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Re: International Aerospace Discussion

Postby brar_w » 13 Feb 2015 21:56

Implications for All F414 users, and for all those considering an NG version of this engine for future products (IAF, ROKAF, Turkish Air Force etc)

GE Successfully Tests World’s First Rotating Ceramic Matrix Composite Material for Next-Gen Combat Engine

CINCINNATI, OH – February 10, 2015 – GE Aviation successfully tested the world’s first non-static set of light-weight, ceramic matrix composite (CMC) parts by running rotating low-pressure turbine blades in a F414 turbofan demonstrator engine designed to further validate the heat-resistant material for high-stress operation in GE’s next-generation Adaptive Engine Technology Demonstrator (AETD) program currently in development with the United States Air Force Research Lab (AFRL).

The introduction of rotating CMC components into the hottest and hardest-working sections of jet engines represents a significant technology breakthrough for GE and the jet propulsion industry. Prior to the F414 CMC demonstrator, successful CMC applications were limited to static parts, like the high pressure turbine shroud that will be installed on the best-selling LEAP engine, by CFM International, a joint company of GE and Snecma (SAFRAN) of France, in development for the Airbus 320neo, Boeing 737 MAX and the COMAC (CHINA) C919 aircraft.

The F414 CMC test -- which endured 500 grueling cycles – validated the unprecedented temperature and durability capabilities of turbine blades made from lightweight, heat-resistant CMCs, allowing for expansive deployment of the advanced manufacturing material in GE’s adaptive cycle combat engine and next-gen commercial engines.

Because the rotating turbine blades made from CMCs are one-third the weight of conventional nickel alloys used in the high-stress turbine, they allow GE to reduce the size and weight of the metal disks to which the CMCs system is connected. “Going from nickel alloys to rotating ceramics inside the engine is the really big jump. But this is pure mechanics,” said Jonathan Blank, general manager of CMC and advanced polymer matrix composite research at GE Aviation. “The lighter blades generate smaller centrifugal force, which means that you can slim down the disk, bearings and other parts. CMCs allow for a revolutionary change in jet engine design.”

GE’s adaptive cycle architecture – the first in which static and rotating CMCs will be deployed -- is revolutionary in its own right. In 2014, GE completed testing the world’s only adaptive three-stream technology demonstrator, called the Adaptive Versatile Engine Technology (ADVENT) engine. The ADVENT engine is the first in aviation history to combine the CMC material technology with an architecture that transitions from a powerful high-pressure, low-bypass ratio fighter jet engine to a fuel-efficient low-pressure, high-bypass ratio commercial engine.

The combination of ADVENT’s revolutionary architectural and material innovations resulted in record-breaking temperature and fuel burn achievements. GE’s AETD program will build on these unprecedented propulsion capabilities to deliver a 25% reduction in specific fuel consumption, 30+ % improvement in range and 10% higher maximum thrust compared to today’s most advanced fifth-generation aircraft.

“One of the key challenges in transitioning CMC to rotating components from static components is the stress field in which they must live. The progression of F414 CMC testing has provided key learnings in making this transition happen for our adaptive cycle engine,” said Dan McCormick, general manager of GE Aviation’s Advanced Combat Engine program. “The CMC low-pressure turbine blade is about one-third the weight of the metal blade it replaces, and at the second stage, the CMC doesn’t have to be air-cooled. The airfoil can now be more aerodynamically efficient because it does not need all that cooling air pumping through the middle of it.”

“More heat means more cooling air, which reduces overall engine performance and efficiency,” Blank said. “By reducing the need for cooling components, our engine becomes aerodynamically more efficient and also more fuel efficient.”

GE’s adaptive cycle engine will be much more durable than conventional engines because the CMC’s material temperature capability is hundreds of degrees higher than legacy nickel-based alloys currently in service in both commercial and military engines.

Since it began developing the technology in the early 1990s, GE Aviation has invested more than $1 billion in CMCs, which are made of silicon carbide ceramic fibers and ceramic resin, manufactured by GE facilities in Delaware and North Carolina through a highly sophisticated process and further enhanced with proprietary coatings. GE’s small-scale CMC production facility in Newark, Delaware, built the turbine components for the F414 test. GE’s mass production facility in Asheville, North Carolina, will produce static parts for the LEAP engine.


Image

Quite an advance for GE. They had the first variable cycle turbofan ever to take flight (YF120) and now they are at the forefront of VC engines with ADVENT. P&W is holding its cards close to chest since they ran their core through IRAD so have no obligation to report progress.

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Re: International Aerospace Discussion

Postby brar_w » 19 Feb 2015 07:29

Deleted

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Re: International Aerospace Discussion

Postby brar_w » 19 Feb 2015 19:57



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Re: International Aerospace Discussion

Postby Singha » 21 Feb 2015 08:16

the stealth model of the MH60 used in osama bin laden kill raid was never seen in public before or thereafter.
a vanilla global hawk is not VLO to be orbiting over his house and relaying imagery and stuff without the pakis radars YLC2 and TPS77 detecting it clearly even at 60,000ft.

so I am sure america has some VLO model of global hawk or entire another HALE uav that is not known to the public under some X program.

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Re: International Aerospace Discussion

Postby brar_w » 21 Feb 2015 17:07

Singha wrote:the stealth model of the MH60 used in osama bin laden kill raid was never seen in public before or thereafter.
a vanilla global hawk is not VLO to be orbiting over his house and relaying imagery and stuff without the pakis radars YLC2 and TPS77 detecting it clearly even at 60,000ft.

so I am sure america has some VLO model of global hawk or entire another HALE uav that is not known to the public under some X program.


The existence of the RQ-180 has been acknowledged by the pentagon. The black budget for the Pentagon is upwards of 50 Billion dollars per year out of which between 15-20 Billion goes to just the USAF . General Atomics just disclosed that they have been supplying one Avenger every 7 months to an undisclosed customer. Given that it is a known Low Observable vehicle the only real reason for the CIA/USAF to keep it in the dark (acquisition) is most likely due to it carrying a payload of sensors or weapons that have not been fully disclosed.

Interestingly, there was a push by the Lockheed Martin Corporation to open up the Skunk works to the media and have it more accessible (also allow many of its scientists to to publish unrestricted papers) and it was revealed a couple of years ago that around 2/3 of what that division does is classified. They threw out this statistics because the media (and to some extent the larger institutional investors in LMC) started asking what tangible activity has happened since they designed the X-35 family. Just a couple of days ago in an interview to Stephen Trimble (interview is going to be published in a few days) the new boss at the skunk works " cited U-2, SR-71 & F-117.... then....: "We have the same kind of initiatives underway today"..Its also an interesting yet futile to find academic papers published by the upper technical leaders in some of these divisions. Some months ago, I was researching advances in composites and materials tech in general and wanted to see what the Skunk Works boss at the time had worked upon, given that he is considered somewhat of a "materials-guru" in the aerospace community. To my surprise I couldn't find a single technical paper published by him pertaining to materials :). A lot of the very high end work is not published even though skunk works usually takes 2 -3 dozen papers every year at AIAA scitech and other such prestigious aerospace conferences.

HALE UAV's existence has been kept in the dark until a couple of years ago when it was revealed to Aviation Week and subsequently to all the media by the head of USAF ISR at the Air Force Association session. They have not revealed anything other then its existence and according to AvWeek its in Low Rate Initial Production..It is considered a strategic ISR assets so not exactly a Global Hawk replacement but a different mission set.

In the black-program-dommain a decision has to be taken whether to disclose the existence of the program around the time its production ramps up. The costs associated with a totally black program are significantly higher at this stage since you have to restrict all program activity at 1 or 2 bases and then you cannot fly at all times etc etc. Basically there has to be a damn good reason to keep a thing secret once you have dozens flying around. The F-117 was a case where a decision was made to hold onto to the announcement for quite a while but even then they were chasing around commercial pilots who radio'd in seeing strange vehicles flying around...One off programs (2-3 vehicles for example) can be kept in the dark indefinitely.

You may want to read -

Secret New UAS Shows Stealth, Efficiency Advances


http://aviationweek.com/defense/secret- ... y-advances

If one is to read up and follow the academic debate and direction with stealth, what led to it, investments made historically and then overlap the programs that have existed since the collapse of the SU ( with what we see today as far as production is concerned - one can realize why the USAF or the pentagon in general is not jumping up and down when the media brings up things like VHF/UHF/L band radars and what not. The first radar-prototype created to test the stealth designs (outside of the radars at the ranges) was a VHF radar created by lockheed martin to test the Have Blue prototypes. There were radar range upgrades performed during the ATF and subsequently the JSF programs, and the largest such upgrade is happening now when the B-3 bomber contracts are expected to be released. They have also covered the radar ranges to some extent so its not entirely possible to use satellite images to see what sort of kit they have at the moment although Sean O Connor has been able to pick up everything from VHF, UHF apertures to S-300 systems at the Groom Lake radar ranges.

http://geimint.blogspot.com/2007/08/us- ... sites.html

You can see in the picture down below, that Lockheed has covered up the mounts and poles at Helendale
and whatever else they have down below and it appears to be a underground facility with a retractable roof that houses the equipment for testing. A large upgrade was performed a couple of years ago as per some reports and there is absolutely no known program that lockheed skunk works is working on for which this could be used. The last known aircraft they developed were the X-35 prototypes and the Polecat.

http://bp2.blogger.com/_0HCJq6B1wZA/Rsg ... ENDALE.jpg



http://www.otherhand.org/home-page/area ... -facility/

At first glance, that fact that it is only a single range with just three target positions, might make one think this is a relatively simple installation. Quite the contrary is true. This is truly a remarkable facility with superbly clever engineering. We’ll start our “tour” of the facility at the south end with the operations center, and proceed downrange (northward) from there.

The Operations Complex is the large cluster of buildings at the very south border of the property. Located here are the office and administrative areas, control rooms, data measurement facilities, hangars for model storage and maintenance (totaling 75,000 square feet), and a 150,000 gallon emergency water reservoir.

On the north side of the Operations Complex is the Antenna Array. This 70′ high tower holds a number of different radar antennas, covering a wide range of frequencies. Hydraulic elevators on the tower move the antennas up or down, to place them in optimum positions for any given test. According to the most recently released public information, the antennas are fed by a 1 kilowatt System Planning Corporation (SPC) MK III radar unit. However the SPC MK III is no longer a “state of the art” unit, now superceded by the SPC MK IV, which is currently the most widely used radar cross section measurement radar in the country. It’s reasonable to assume the Helendale facility has upgraded to a MK IV unit by now. (The MK V radar unit, which will use a Windows (!) control system, is about to enter prototype stage.)

Extending north from the Antenna Array is the range itself. It is a 300′ wide asphalt surface 3″ thick, extending for the next 7,500′ The surface is absolutely flat, with even the curvature of the earth removed. At least initially after construction, the surface was dusted with sand so that pilots wouldn’t mistake it for a landing strip, and also to reduce radio wave distortion from heat shimmers.

Rather than trying to defeat the ground plane effect inherent in ground plane type radar ranges, this range has been designed to take advantage of the multipath bounce of the radar beam off the asphalted surface. This increases sensitivity by about 12 db.

Moving 1,400′ downrange from the Antenna Array, we come to Antenna Pit 1. At this location, test objects can be placed upon four different mounts. The support may be either a 14′ long metal or composite pylon, a foam column, or an inflated air column. The targets mounted at Pit 1 may be up to 14′ in length and weigh up to 1,600 pounds. The targets here are placed upon the mount using either a crane or forklift.

Immediately uprange of Pit 1, visible on the surface of the range, is a long white metal cover. Under this cover is a hinged calibration pylon. Prior to testing a model at Pit 1, the calibration pylon is extended with a known, measured shape mounted on it. The technicians at the operations complex can then adjust and calibrate their equipment on the basis of a known shape. The calibration pylon is then retracted and an actual model measured.

Moving next to a point 5,000′ from the antenna array, we come to Pit 2. This 80′ deep pit is covered by hinged white doors on the surface and contains a pylon extended by means of a hydraulic ram. Just beneath these doors, and above the retracted pylon is a small workroom in which models up to 50′ in length and weighing up to 6,000 pounds may be mounted to the pylon. Immediately adjacent and uprange to Pit 2 is a much smaller pit containing a calibration shape mounted on a hinged pylon. It functions in the same manner as the calibration pit for Pit 1.


The jewel of the facility is found at the 7,500′ point. This curious structure, in the depression at the far end of the range, is known as the “Upper Chamber” (or Area 30 during construction). Although it appears to be built of solid concrete, it is actually composed of concrete blocks. On the side of the structure with the vertical face, there is a large, side-sliding hangar door in the 40′ high face of the structure. It is through this door that models are brought into the Upper Chamber.

Careful inspection of the Upper Chamber’s roof reveals what appears to be a square cover, 80′ on a side, with a split along a diagonal. This cover retracts on two sides, separating along the diagonal, exposing an 80′ square opening into the Upper Chamber below. When closed, an air bag arrangement seals the diagonal seam.

Surprisingly, the useable area within the Upper Chamber is less than it appears when viewed from outside. Actual level floor space is only about 130′ by 110′, about 14,000 square feet. Most of the area apparently covered in concrete surrounding the Upper Chamber is actually covered slope. At the time of construction this area was not utilized and left as covered, but bare slope.

The area within the Upper Chamber is primarily a workroom and staging area. There is a large overhead traveling bridge hoist for the movement and manipulation of RCS models. There is also a diesel generator, a control room, restrooms and a small winch room off to one end. There are no office areas. The right rear portion of the Upper Chamber is dominated by the Silo and its cover.

Image





Some other very interesting pictures of this facility that is fully owned and operated by Lockheed Martin are in the detailed write up from the link posted above. Other facilities owned by other OEMs also exist and there are other dedicated and more secretive facilities owned by the USAF, jointly operated by the USAF and CIA and owned by the USN. From my readings on the matter both Boeing and Northrop rely on Lockheed to provide them with bulk RCS measurement for their products even when they compete with Lockheed.

An interesting Anecdote that Ben Rich shared in his excellent book on the history of his organization was from the time when the stealth research was only getting started (practical phase of actually mounting stuff at the range)..The contract to develop very high end Poles for precise RCS measurement went to Lockheed and when they debuted their pole its RCS figures prompted one of the engineers from Northrop to comment " Damn, if they can hit those numbers with a pole, what can they do with an aircraft".

The 737 pictured above is a specialty aircraft that takes radar signatures and measures them over time especially pre and post treatments and maintain..Its one of the things that any nation that wishes to maintain a strength of VLO aircraft has to invest in if it wants to fully utilize the capability.
Last edited by brar_w on 22 Feb 2015 03:42, edited 2 times in total.

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Re: International Aerospace Discussion

Postby SaiK » 21 Feb 2015 23:02


brar_w
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Re: International Aerospace Discussion

Postby brar_w » 23 Feb 2015 05:03

F-22A B-Roll Red-Flag-15/1


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Re: International Aerospace Discussion

Postby brar_w » 23 Feb 2015 21:19

kit wrote:As regards both stealth planes and submarines there is a new conundrum that might be taken as disruptive . EM signals in the present day are widely dispersed in say for example cell phone towers and bi static radars ..any object that moves will create interference proportional to the size of the object . Enough computing power., passive EM gear and software can detect stealth planes as well as super quiet subs ( in the same logic ) . .. i think a lot of research is going on especially in China and Russia that could as well make american lead in technology obsolete ..Raw computing power was one factor this hasn't progressed much before but no longer the case .But as usual one has to keep up with current threats too while looking at a future that could very well be stealth robotic planes send in swarms by a flying aircraft carrier .. fiction ? ..not so !


This is obviously assuming that an equally proportional research is not being carried out to not only understand the counter-stealth tactics, technology, and devise strategies to counter them and to further maintain if not extend that lead. Thats a fairly large leap of faith given the size of the Air-Force specific Pentagon Classified budget. Like I said earlier, we usually hear these things 10-12 years later of what unique systems were ordered and even then its usually a glimpse into a very small segement of what is being researched and generally a brief mention (usually one line). Most of the stealth-vs-counter stealth debate has ignited in spurts at times when the western media has had a chance to visit either Russian or Chinese AESA developments at air-shows. The computing power debate was actually (to the best of my knowledge) based from a DOD document highlighting the counter advances sometime in the late 90's when they were developing the Next Gen Bomber precursors. Anyhow, there is absolutely ZERO information on stealth advances following the ATF competitions in the 90's. The only direct media-communicated released for the F-35 has been a brief mention of FiberMat that had been known to exist even during the ATF days as a future enhancements to later block F-22's. The best way therefore for those interested in following the stealth-developments is to look at the importance being placed on stealth for future designs, be it UAV's, Bombers, future fighters, stand off missiles etc etc etc. There is no indication at any DOD released policy, RFI or any other technical document claiming that they are moving away from "stealth is the primary design driver" in vehicles that would be ripe candidates for its adoption. There is more (a lot more) on this in the academia and technical journals but then again, its unlikely to capture the collective imagination of the US (and I assume western) defense media that unfortunately at the moment is just a collection of reporters without any signfiicant technical background who's only real ambitions is to interview and get the first scoop on contract, sequester or other such activities. Gone are the days when you had strong engineering backgrounds int he core media publications that would do a 5000+ word assessment of technical capabilities. You have some now, but the online nature of the content and competition (war is boring type blogs) is forcing them into a different direction.

Anyhow, the shape of things to come would soon be visible, both the B-3 and the Next Gen Advanced Air Dominance initiative are on at the moment, and most in the S&T are not dumb enough to place stealth at the cornerstone of these efforts if someone blogging somewhere could figure out the complete stealth vs counter stealth debate.

As far as the JSF being too big to fail, its been called that in the media (and how does one stop them from doing anything anyhow) but at the Air force and DOD level its too important to fail given the magnitude of the modernization effort planned over the next 2 decades of which the JSF is one important but not exclusive part. The F-16 at a similar time-frame was too big to fail if only that phrase had caught the attention of the popular press at the time when it was crashing all over the place and final configuration was being delayed till post 1000 units production.

As far as advances in computing and bi-statit and other radar enhancements (VHF,UHF aAESA etc) that is and has been a factor in both designing and testing stealth designs for decades..VHF radars have been designed, procured or prototypes of advanced future concepts delivered to the test and development community. Again the pattern goes quiet from around the late 90's so what has happened since then (when the biggest DOLLAR amount R&D into stealth has taken place post 2000 with the JSF, J-UCAS and NGB/LRS-B programs) has not been properly communicated for obvious secrecy reasons. From what is known VHF radars have been delivered, UHF radars are operational and other more secret flying sensors that as per some reports include bi-static aerial sensors (737) have been flying around since the turn of the century. So development of stealth has not occurred in a vacuum especially when the same designers and customers intend to develop and maintain a lead in advanced sensors, computing and other such high-technology areas. Those designing stealth (i expect the IAF to do the same) factor in the technology roadmap and chart out what advantage extends to what time-frame given the trends in S&T development especially if your own initiatives in advanced sensors, testing stealth and counter stealth have been significant over the last 2-3 decades. Ultimately, stealth is one aspect of breaking the kill chain, the EM spectrum is complex and it is planned to (even by those developing advanced stealth aircraft ) be tackled at multiple levels.

Anyhow, the contention of this line of reasoning was that Mort thought I was ridiculing him, which was not the case/intention. All I was saying was given that we only know one number that is the best aspect of the RCS either we use it, or we use no number since there is not even a credible guess flying around of what the all aspect RCS of this particular aircraft is (hence the reference to 1sqm).

The media has done a horrible job with the VHF and UHF vs Stealth debate for example where one has to look at the academia for some credible information and discussion on what has happened and is still happening in that domain. The picture being painted is that the VHF or UHF threat is growing all of a sudden and most working on stealth have been caught off guard, when there is evidence (significant) even in the open "Google" type efforts to prove otherwise. If one digs deeper into various stealth programs one can gain a greater appreciation of efforts to not only test against this threat but also on how to counter it. In the end stealth is one very significant way of tackling the EM spectrum, and possibly the best way to gain a significant tactical and strategic advantage along with other soft and kinetic options. It is not a be all end all of survivability as has been poorly portrayed in the media, yet it is also not something that will get obsolete in a matter of years or even decades, aircraft designed NOW that are to be operational for the next 3-5 decades are having it as a primary design feature (around the world) and some in the blogosphere and the media at large have painted these efforts without any evidence other then a cursory explanation of the evolving threat (Computing, VHF/UHF proliferating AESA - something that was itself mentioned in DOD intel briefs during earlier stealth design efforts) with little to no mention of any tactics, technologies or capabilities being worked on, incorporated or planned for the blue force.

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Re: International Aerospace Discussion

Postby kit » 23 Feb 2015 23:12

brar_w wrote:
kit wrote:As regards both stealth planes and submarines there is a new conundrum that might be taken as disruptive . EM signals in the present day are widely dispersed in say for example cell phone towers and bi static radars ..any object that moves will create interference proportional to the size of the object . Enough computing power., passive EM gear and software can detect stealth planes as well as super quiet subs ( in the same logic ) . .. i think a lot of research is going on especially in China and Russia that could as well make american lead in technology obsolete ..Raw computing power was one factor this hasn't progressed much before but no longer the case .But as usual one has to keep up with current threats too while looking at a future that could very well be stealth robotic planes send in swarms by a flying aircraft carrier .. fiction ? ..not so !


This is obviously assuming that an equally proportional research is not being carried out to not only understand the counter-stealth tactics, technology, and devise strategies to counter them and to further maintain if not extend that lead. Thats a fairly large leap of faith given the size of the Air-Force specific Pentagon Classified budget. Like I said earlier, we usually hear these things 10-12 years later of what unique systems were ordered and even then its usually a glimpse into a very small segement of what is being researched and generally a brief mention (usually one line). Most of the stealth-vs-counter stealth debate has ignited in spurts at times when the western media has had a chance to visit either Russian or Chinese AESA developments at air-shows. The computing power debate was actually (to the best of my knowledge) based from a DOD document highlighting the counter advances sometime in the late 90's when they were developing the Next Gen Bomber precursors. Anyhow, there is absolutely ZERO information on stealth advances following the ATF competitions in the 90's. The only direct media-communicated released for the F-35 has been a brief mention of FiberMat that had been known to exist even during the ATF days as a future enhancements to later block F-22's. The best way therefore for those interested in following the stealth-developments is to look at the importance being placed on stealth for future designs, be it UAV's, Bombers, future fighters, stand off missiles etc etc etc. There is no indication at any DOD released policy, RFI or any other technical document claiming that they are moving away from "stealth is the primary design driver" in vehicles that would be ripe candidates for its adoption. There is more (a lot more) on this in the academia and technical journals but then again, its unlikely to capture the collective imagination of the US (and I assume western) defense media that unfortunately at the moment is just a collection of reporters without any signfiicant technical background who's only real ambitions is to interview and get the first scoop on contract, sequester or other such activities. Gone are the days when you had strong engineering backgrounds int he core media publications that would do a 5000+ word assessment of technical capabilities. You have some now, but the online nature of the content and competition (war is boring type blogs) is forcing them into a different direction.

Anyhow, the shape of things to come would soon be visible, both the B-3 and the Next Gen Advanced Air Dominance initiative are on at the moment, and most in the S&T are not dumb enough to place stealth at the cornerstone of these efforts if someone blogging somewhere could figure out the complete stealth vs counter stealth debate.

As far as the JSF being too big to fail, its been called that in the media (and how does one stop them from doing anything anyhow) but at the Air force and DOD level its too important to fail given the magnitude of the modernization effort planned over the next 2 decades of which the JSF is one important but not exclusive part. The F-16 at a similar time-frame was too big to fail if only that phrase had caught the attention of the popular press at the time when it was crashing all over the place and final configuration was being delayed till post 1000 units production.

As far as advances in computing and bi-statit and other radar enhancements (VHF,UHF aAESA etc) that is and has been a factor in both designing and testing stealth designs for decades..VHF radars have been designed, procured or prototypes of advanced future concepts delivered to the test and development community. Again the pattern goes quiet from around the late 90's so what has happened since then (when the biggest DOLLAR amount R&D into stealth has taken place post 2000 with the JSF, J-UCAS and NGB/LRS-B programs) has not been properly communicated for obvious secrecy reasons. From what is known VHF radars have been delivered, UHF radars are operational and other more secret flying sensors that as per some reports include bi-static aerial sensors (737) have been flying around since the turn of the century. So development of stealth has not occurred in a vacuum especially when the same designers and customers intend to develop and maintain a lead in advanced sensors, computing and other such high-technology areas. Those designing stealth (i expect the IAF to do the same) factor in the technology roadmap and chart out what advantage extends to what time-frame given the trends in S&T development especially if your own initiatives in advanced sensors, testing stealth and counter stealth have been significant over the last 2-3 decades. Ultimately, stealth is one aspect of breaking the kill chain, the EM spectrum is complex and it is planned to (even by those developing advanced stealth aircraft ) be tackled at multiple levels.

Anyhow, the contention of this line of reasoning was that Mort thought I was ridiculing him, which was not the case/intention. All I was saying was given that we only know one number that is the best aspect of the RCS either we use it, or we use no number since there is not even a credible guess flying around of what the all aspect RCS of this particular aircraft is (hence the reference to 1sqm).

The media has done a horrible job with the VHF and UHF vs Stealth debate for example where one has to look at the academia for some credible information and discussion on what has happened and is still happening in that domain. The picture being painted is that the VHF or UHF threat is growing all of a sudden and most working on stealth have been caught off guard, when there is evidence (significant) even in the open "Google" type efforts to prove otherwise. If one digs deeper into various stealth programs one can gain a greater appreciation of efforts to not only test against this threat but also on how to counter it. In the end stealth is one very significant way of tackling the EM spectrum, and possibly the best way to gain a significant tactical and strategic advantage along with other soft and kinetic options. It is not a be all end all of survivability as has been poorly portrayed in the media, yet it is also not something that will get obsolete in a matter of years or even decades, aircraft designed NOW that are to be operational for the next 3-5 decades are having it as a primary design feature (around the world) and some in the blogosphere and the media at large have painted these efforts without any evidence other then a cursory explanation of the evolving threat (Computing, VHF/UHF proliferating AESA - something that was itself mentioned in DOD intel briefs during earlier stealth design efforts) with little to no mention of any tactics, technologies or capabilities being worked on, incorporated or planned for the blue force.


Great write up ! ..thanks ..anyway osit is only so much !

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Re: International Aerospace Discussion

Postby brar_w » 23 Feb 2015 23:38

See this:

In mid-2000 the Lockheed Martin Advanced Prototype Center, part of the Advanced Development Programs' (ADP) organization, handed over its first major deliverable -- a flight-worthy composite structure -- on the center's first design and fabrication contract. The structure, a 19-foot long, 6.2-foot diameter fairing and bulkhead assembly, was delivered to customer DENMAR Inc. The prime contractor Denmar is a company specializing in stealth technology. The "Den" stands for President Denys Overholser, the former Skunk Works engineer credited with devising the shape of the first stealth aircraft. The assembly provides an aerodynamic transition from the existing aft fuselage of a T-43 aircraft, a modified Boeing 737-200, to an oversized radome. The aircraft serves as a Radar Test Bed (RTB) for future Air Force programs. The design, fabrication and machining of the structure's components were all performed at Palmdale. The structure is made of a 90-percent carbon epoxy/honeycomb sandwich material, with machined aluminum parts, and houses an airborne radar assembly. The contract with DENMAR also included the design and fabrication of three radomes for the RTB aircraft. Each radome is more than 6.5 feet in diameter and 9 feet in length. Technical papers from Rome Lab reference a bistatic Advanced Airborne Surveillance system-originally due to be demonstrated in 2000, and a graphic in a Lincoln Lab briefing paper showed a bistatic radar with its transmitter mounted on a 737. The Advanced Radar Test Bed [ARTB] was based on a Lockheed NC-141 (tail number 61-2779).


Image

There have been some very open, fully defense and defense-university (partnership) funded research programs in the bistatic radar domain. The Covin Rest program demonstrated unique SAR image possibilities in the mid 80's by using space based and ground based systems. Of late, MIT, and particularly teams in Michigan have been working on these systems (Multistatic). It would be quite naive to think that on the back of nearly 30 years of research into the matter, they wouldn't have developed (along the way) prototype systems to test out the tremendous investments they have been making at defeating these very systems. One runs into trouble if one believes these systems (stealth aircraft) to be invisible to radar and therefore invincible to integrated air defenses. As I have written in the past, if one were to read up on the B-2 Bomber development, the estimates at that time were that 20% of the fleet of B-2's at the time would be lost to Air Defenses. They had worked out similar numbers for the F-117 (For both consult Ben Rich's book that gives a unique perspective on both competitions). The reason why stealth was and still is so appealing, and why all with the cash and technical capability are diving into it (Russians (PAKFA, PAKDA, SKAT etc), Chinese, India, Japan etc) is because it is still the best way to tilt the odds and penetrate hostile airspace with any remote chance of surviving. to borrow (and rephrase) from In The Loop : And at the end of a war you need some soldiers/aircraft left, really, or else it looks like you've lost...Stealth by no means is a "One trick Pony" and hasn't been designed to be..It works hand in glove with electronic warfare, cyber and kinetic options to overwhelm air-defenses. Its been like that pretty much since the B-2..

VHF radars have also been covered by many photographers throughout the last 10-15 years. Some are old, developed in the late 80's - mid 90's and upgraded, yet others following the test ranges have seen increasing activity to cover things up so that a lot of the newer stuff can be hidden. Also keep in mind that Project Palladium was at the time widely believed to be the most successful effort of its kind. It still exists at the moment though a lot of its activity has since been merged into NSA's project Musketeer. Other projects have had successful purchase of export radars and equipment like the S-300 sensors have also emerged with Sean O Conner documenting many S-300 elements at the classified radar test sites. Keep in mind, that if retired-experts can use commercially available google_earth type setups to detect something, then it is most likely not meant to be kept hidden. The most secretive sensors would be the prototype sensors you would develop utilizing the advances in your own electronics and aerospace industry that aim to project / simualte air-defense capabilities 10, 20 years from now. You won't pick them up on google earth unless there is a major screwup somewhere :) Another thing to keep in mind that Iran has indigenous VHF radars for some time and has shown off the NEBU SVU radar quite publicly. Outside of the general diplomatic rumblings no contractual activity has followed to counter these systems..The capability and limitations of both the radars against current known and unknown (to us) systems, as well as the capability and limitations of current known and unknown (to us) systems against these type of things are probably very well understood for the trail (documented trail, covered by publications over time) of using VHF radars against stealth at the ranges has been documented for years (F-117 days).

To end, I'll quote Sherm Mullin from his write up on the F-22 (2nd best resource on the aircraft imho), the skunk who was one of the leads on the F-22 - 'There are many disbelievers in stealth, more than a few of them truly technically ignorant and proud of it
Last edited by brar_w on 24 Feb 2015 09:35, edited 3 times in total.

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Re: International Aerospace Discussion

Postby Mort Walker » 24 Feb 2015 07:34

^^^Your link doesn't work.

What has happened is that conventional pulsed radar has been around since WWII and is a fairly understood technology. It has been incorporated in to air defense networks world wide. Stealth has become important in the last 30 years where detection by older legacy design radars becomes orders of magnitude more difficult. Now that stealth technology is becoming more available world wide, radar system design has to be revisited. Bistatic and multistatic radar is being looked at again when it was in vogue over 70 years ago. In fact, the Chain Home radar system incorporated by Britain in WWII was type of bistatic or multistatic radar.

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Re: International Aerospace Discussion

Postby brar_w » 24 Feb 2015 07:43

Mort Walker wrote:^^^Your link doesn't work.

What has happened is that conventional pulsed radar has been around since WWII and is a fairly understood technology. It has been incorporated in to air defense networks world wide. Stealth has become important in the last 30 years where detection by older legacy design radars becomes orders of magnitude more difficult. Now that stealth technology is becoming more available world wide, radar system design has to be revisited. Bistatic and multistatic radar is being looked at again when it was in vogue over 70 years ago. In fact, the Chain Home radar system incorporated by Britain in WWII was type of bistatic or multistatic radar.


Here you go:

http://www.globalsecurity.org/military/ ... t/t-43.htm

Image


Of course different radar designs are being looked at and their would always a constant development in that area. My point of writing that post was that most of the discussion in the open media has been very heavily focused on pitting current stealthy systems vs a threat with zilch effort to explore whether steps have been taken to understand or design against that level of threat. A lot of the media still equates stealth with invisibility which was never the case to begin with (attrition numbers built into the expectations at the design/concept stage attest to that very fact). An almost 'religious' attention is paid to paint those designing VLO aircraft as being ignorant of radar developments when the investments in understanding the threat have been significant - even based on what is known in the open either in the reports from media itself or published in academia.

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Re: International Aerospace Discussion

Postby Shreeman » 25 Feb 2015 11:47

As long as we are posting ugly:

Image

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Re: International Aerospace Discussion

Postby PratikDas » 27 Feb 2015 07:34

(Realised this probably doesn't belong to the Indian Military Aviation thread)

Dhruv helicopter accident of January 27



Janes, January 27: Ecuador loses another Dhruv helo to crash
The Ecuadorian Air Force (Fuerza Aérea Ecuatoriana: FAE) lost a Hindustan Aeronautics Limited (HAL) Dhruv utility helicopter to a training accident in late January, the second to be lost this month and the fourth since deliveries began in 2009.

Indranil
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Re: International Aerospace Discussion

Postby Indranil » 27 Feb 2015 08:20

That is very interesting. Thanks for sharing. I may be hurried in writing this. But that looks like loss of lift suddenly because of ground effect.

There is a steep fall right where the tarmac ends. The helicopter was traversing close to the ground (less than half a rotor diameter above ground) when it crosses this ledge and also from paved tarmac to grasslands. It seems to lose lift rapidly and plunges. This looks like a loss in lift because of transition from IGE to OGE.

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Re: International Aerospace Discussion

Postby neerajb » 27 Feb 2015 09:13

Why did it turn left before going down? Maybe it was not part of the schedule to go outside of the runway? Trainee tried to correct it by turning left but the momentum carried it beyond that point and IGE to OGE caused it to loose lift rapidly and before the situation could be corrected it crashed.

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Re: International Aerospace Discussion

Postby Indranil » 27 Feb 2015 10:45

I feel that was uncommanded too. With the change in efficiency of the rotors, the torques would have become unbalanced. That transition should be very slow over that ledge or they should go out of ground effect before the transition occurs.

Just goes to show the skills and discipline of the pilots landing and taking off from those shaky ledges during the rescue efforts in the recent Uttarakhand floods.

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Re: International Aerospace Discussion

Postby deejay » 27 Feb 2015 11:52

Indranil, agree with you. This is a table top helipad take off. The 'valley' winds will be different from helipad. The helicopter did a sudden transition from IGE to OGE (That is for sure).

But, I think, this alone will not justify the drop of the helicopter. As a first step let me put a disclaimer before saying anything further - It is best to wait for the official inquiry into the accident. Everything else is speculation, that too with insufficient data and with (most probably) insufficient expertise.

And then lemme share my opinions anyways. IMO (humble onlee) there could be few reasons for the drop:
a) Engine failure (no visible signs)
b) Very strong down draught. (again there is no smoke or flag visible to judge valley winds and the helipad is disturbed by the rotor downwash so we can see the trees around shake vigorously)
c) Control mishandling aggravating a 'delicate' situation.

The turn of the helicopter to the left while going down could be because:
a) Pilot increased collective to increase power but did not counter the increased torque through adequate rudder application.
b) Problems with Tail rotor (mechanical or aerodynamic as in Tail Rotor Vortex kind of thing. The tail rotor vortex mostly happens in landing or vertical descents).

Added Later: Mostly, aircraft accidents have been caused by a chain of events / multiple events and not a single cause)
Last edited by deejay on 27 Feb 2015 18:49, edited 1 time in total.

Indranil
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Re: International Aerospace Discussion

Postby Indranil » 27 Feb 2015 14:05

Agreed in all respects.


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