Israel Has 2Nd Thoughts about V-22 Acquisition

V-22s Range Advantage has a Cost

Israel seemed poised to purchase the tilt-rotor V-22 Osprey, and now they have put this on hold.

I am not particularly surprised.

The V-22 is a maintenance hog, and cost a fair amount to operate.

While the Osprey is about 100 kts faster, has a longer range, it can only carry about 1/3 of the payload, even though it has 2/3 of the installed power.

Additionally, unlike a conventional helicopter, the V-22 does not have a meaningful auto-rotation capability, and its performance with external loads is pathetic.

Israel simply does not have the need for the additional capabilities offered by the tilt-rotor:

The Israeli air force has frozen its evaluation of the Bell Boeing V-22 Osprey, with a senior defence source indicating that the tiltrotor is unable to perform some missions currently conducted using its Sikorsky CH-53 transport helicopters.

In January 2014, the US Department of Defense notified Congress about its intention to sell six V-22s to Israel. This followed an evaluation conducted by air force personnel, which led to the service seeking a rapid acquisition to support special operations. The proposed purchase met with opposition from elsewhere within Israel's defence ministry, however.

Other potential candidates to replace the Israeli air force's aged CH-53s by around 2025 include Sikorsky's new CH-53K and the Boeing CH-47 Chinook.

Simply put, the IDF does not have the requirements, such as amphibious landings from extreme distance, that have driven the V-22, and as such, it does not make sense.

Have Some Helicopter Pr0n

I present to you the Sikorsky S-97 Raider:


I favor this over a tilt-rotor.

I want my rotor craft to auto-rotate in the event of an engine failure.

Sikorsky S-97 Raider Takes Flight

Click any image for popup slide show

---

Flight


Taxiing


Tethered Tests


Rendering showing rotor and hub fairings

Sikorsky's S-97 Raider advancing blade helicopter prototype has
taken flight at their test center in Florida:

Sikorsky’s “big bet” on the future of rotorcraft took a sizable step forward on May 22, when the S-97 Raider high-speed helicopter made its first flight, almost eight decades after founder Igor Sikorsky set the mold for the helicopter by flying the VS-300.

With its single main rotor and anti-torque tail rotor, the VS-300 solidified a configuration that has come to dominate the rotorcraft market, but also set a speed limit of around 150 kt. that has not changed significantly for 30 years.

With its rigid coaxial rotors and pusher propulsor, Sikorsky believes the Raider and subsequent designs can change the vertical-lift market by offering twice the cruise speed while retaining the low-speed attributes of conventional helicopters, but with higher hot-and-high performance, efficiency and maneuverability, and lower noise, vibration and pilot workload.

The aircraft flown on May 22 is the first of two prototypes of the Raider light tactical helicopter being built under a $200 million industry effort funded by Sikorsky and its supplier partners. This follows on from the $50 million company-funded X2 Technology Demonstrator, which flew 23 times from 2008-11 and exceeded its speed goal of 250 kt.

On its first flight at Sikorsky’s development flight center in West Palm Beach, Florida, the Raider flew for an hour, versus the 30 min. planned, says Mark Miller, vice president of research and engineering, completing three takeoffs and landings, and forward, rearward and sideward flight. The aircraft was flown by Raider chief pilot Bill Fell, with X2 test pilot Kevin Bredenbeck as co-pilot.

Where the 6,000-lb.-gross-weight X2 proved the physics of the rigid coaxial-rotor compound helicopter, Miller says, the production-representative 11,400-lb. Raiders are intended to show their operational effectiveness through customer demonstrations. They will also reduce risk for the 30,000-lb. SB-1 Defiant Sikorsky is building with Boeing for the U.S. Army’s Joint Multi Role technology demonstration.

Rolled out in October, the first Raider had completed 36 hr. of shakedown ground runs since February. This culminated in an untethered ground run on May 20, clearing the aircraft for flight. On the hour-long first sortie, which was limited only by fuel, all 97 points on an “aggressive” test card were completed, including piloted frequency sweeps in all axes, something normally too risky for a first flight, says Fell.

Initially, the Raider is flying with its triplex fly-by-wire flight control system in back-up degraded mode to reduce complexity and focus on basic airworthiness in the low-speed regime. “There is phenomenal control power with the rigid rotors,” he says. “You can make an input in roll or pitch and the aircraft responds immediately. And with no tail rotor, you do not have to manage the pedals.”

………

The Raider will be flown to 140-150 kt. in pure helicopter mode, says Miller. Toward the end of Phase 1, software will be upgraded to Block 2, bringing in the variable-pitch propulsor and articulating tail to increase speed and enable the full flight envelope. Hub and inter-rotor fairings will be fitted to reduce drag.

Phases 1 and 2 will demo the hover KPP carrying the equivalent of six troops and two crew, as well as an endurance objective. Phase 2 will focus on demonstrating—and likely exceeding—the speed objective when fitted with stub wings carrying weapons. “Raider is a balanced design optimized for more than 220 kt. fully weaponized, but the inherent speed of the configuration is more than 250 kt.,” says Miller. “That’s 100 kt. faster than anything else.”

Phase 3 will demo the maneuverability potential of the rigid coaxial rotor and propulsor. In addition to enabling level-attitude acceleration and deceleration and pushing the helicopter to higher forward speeds, the variable-pitch propeller can be used to produce reverse thrust, enabling the Raider to “hang on the prop” to point sensors and weapons toward the ground.

………

The Raider will be flown to 140-150 kt. in pure helicopter mode, says Miller. Toward the end of Phase 1, software will be upgraded to Block 2, bringing in the variable-pitch propulsor and articulating tail to increase speed and enable the full flight envelope. Hub and inter-rotor fairings will be fitted to reduce drag.

[Aircraft 1 is instrumented for envelope expansion, Hub and inter-rotor “sail” fairings for high speed are not yet fitted. Credit: Sikorsky]
Aircraft 1 is instrumented for envelope expansion, Hub and inter-rotor “sail” fairings for high speed are not yet fitted. Credit: Sikorsky

Phases 1 and 2 will demo the hover KPP carrying the equivalent of six troops and two crew, as well as an endurance objective. Phase 2 will focus on demonstrating—and likely exceeding—the speed objective when fitted with stub wings carrying weapons. “Raider is a balanced design optimized for more than 220 kt. fully weaponized, but the inherent speed of the configuration is more than 250 kt.,” says Miller. “That’s 100 kt. faster than anything else.”

Phase 3 will demo the maneuverability potential of the rigid coaxial rotor and propulsor. In addition to enabling level-attitude acceleration and deceleration and pushing the helicopter to higher forward speeds, the variable-pitch propeller can be used to produce reverse thrust, enabling the Raider to “hang on the prop” to point sensors and weapons toward the ground.

The early tests will involve low, conventional helicopter, speed.  As the test moves to higher speeds, fairings will apply to the mast and rotor hubs.

Right now, there are two competing technologies for high speed vertical lift for the US military,  advancing blade, and tilt rotor.

Tilt rotor appears to offer superior performance in horizontal flight, at the cost of increased down wash issues, less capable low speed handling, and a larger ground envelope.

I'm inclined to go with the advancing blade.  I think that it is an inherently safer technology (autorotation), and the implementation seems to involve a lot less "bleeding edge" technology.  (The V-22's high pressure hydraulic system, necessary to keep weight down, has been a maintenance nightmare).

We are Halfway to Boots on the Ground in Iraq

We are now deploying attack helicopters to Iraq:

The United States sent attack helicopters into combat against Islamic State targets west of Baghdad on Sunday, the first time low-flying Army aircraft have been committed to fighting in an engagement that the Obama administration has promised would not include “boots on the ground.”

The U.S. Central Command, in a statement about U.S. activities against the Islamic State in Iraq and Syria, provided few specifics about the helicopters. But they were likely AH-64 Apache attack helicopters, which were deployed to Baghdad International Airport in June to provide protection for U.S. military and diplomatic facilities.

Until Sunday, U.S. airstrikes in Iraq have been limited to fast-moving Air Force and Navy fighter aircraft and drones. But the use of the relatively slow-flying helicopters represents an escalation of American military involvement and is a sign that the security situation in Iraq’s Anbar province is deteriorating. Last week, the Islamic State militants overran numerous Iraqi bases and towns and were becoming a widespread presence in Abu Ghraib, the last major town outside of Baghdad’s western suburbs.

Jeffrey White, a former senior Defense Intelligence Agency analyst who closely follows developments in Iraq, said the use of helicopter gunships by the United States means that U.S. troops effectively are now directly involved in ground battles.

(emphasis mine)

Note that, notwithstanding their design for damage resistance, Apaches have been taken down by small arms fire.

Add a few ZSUs (self propelled anti-aircraft artillery) to the mix, and we are going be have helicopters shot down, and either a very risky rescue mission or US troops held prisoner.

We are going to be back in ground combat sooner rather than later.

Barack Obama now owns the "stupid war" that he opposed in 2003.

JMR Demonstrators Downselected

Valor


Defiant

Bell's Tilt Rotor and the Sikorsky/Boeing coaxial rotor helo have been selected to produce the two Joint Multi Role technology demonstration (JMR TD) vehicles:

Bell Helicopter and Sikorsky/Boeing have been selected to build high-speed rotorcraft technology demonstrators for the U.S. Army. Both aircraft are scheduled to fly in 2017.

Bell will build the 280-kt. V-280 Valor tiltrotor and Sikorsky/Boeing the 230 kt.-plus SB.1 Defiant rigid coaxial-rotor compound helicopter under the $217 million first phase of the Joint Multi Role technology demonstration (JMR TD).

JMR TD is the precursor to the Army’s planned Future Vertical Lift Medium (FVL-M) program to replace the Sikorsky UH-60 Black Hawk utility helicopter from the mid-2030s onward. Later an attack derivative could replace the Boeing AH-64 Apache and a marinized version of the Navy’s MH-60 Seahawk.

The two other competitors for JMR TD Phase 1, small companies AVX Aircraft and Karem Aircraft, are expected to receive Army contracts for some level of continued technology development. AVX was proposing a 230-kt. coaxial-rotor compound and Karem a variable-speed tiltrotor.

Both demonstrators have about the same installed HP, around 3300 KW, which is about double that of the Black Hawk helicopter which they are slated to replace, though to be fair, the gross weight is about is about 35% more than the Black Hawk.

I'm inclined to go with the helicopter over the tilt rotor, because I like the idea of being able to autorotate if things go bad, and because the history of tilt-rotors is one of high costs, low reliability, and a large footprint, while coaxial helicopters have been in deployment (albeit Soviet/Russian deployment) for over 40 years.

Here is a Bit of Neat Tiny Aviation Tech

AugustaWestland is looking at variable geometry rotors using a miniscule (1-2% of chord) trailing edge flap which can be extended of retracted under different conditions:

Dan Gurney, American racing car driver and constructor, is providing inspiration to European helicopter manufacturers, with AgustaWestland planning in 2015 to fly an active rotor incorporating the aerodynamic device that carries his name.

The Gurney flap (see diagram) is a small tab set perpendicular to the flow at the trailing edge of a wing. It has the effect of increasing lift with minimal impact on drag. In the early 1970s, he first used the eponymous device on the rear wing of a racing car to increase downforce.

In the interest of accuracy, the Gurney flap, also known as a wickerbill, was actually independently invented by a number of people as far back as 1931

Fixed Gurney flaps are used extensively on helicopters to increase the effectiveness of horizontal and vertical stabilizers over a wide angle-of-attack range. Now, with funding from Europe's Clean Sky research program, AgustaWestland is to use active Gurney flaps to increase the performance of helicopter rotor blades.

Rotor design is a compromise between hover and forward-flight requirements, and the ability to squeeze more performance from conventional blades is reaching its limits. “In the 1980s and '90s we saw big gains. Now they are smaller. We have more powerful computational tools, but are only getting incremental gains,” says Simon Spurway, AgustaWestland principal engineer. “The next step is active rotors.”

Under Clean Sky's Green Rotorcraft program, Airbus Helicopters is leading work to see how much further a conventional blade can be passively optimized. The manufacturer also is heading a project to develop active blade twist, which Spurway says poses fail-safe design challenges. AgustaWestland, meanwhile, is in charge of the active Gurney flap project.

Projecting from the lower surface close to the trailing edge, and just 1-2% of blade chord in height, the flap produces counter-rotating vortices that increase pressure on the lower, pressure side of the airfoil and decrease pressure on the upper, suction side. The vortices help the boundary stay attached to the trailing edge and increase the maximum lift coefficient for only a small penalty in drag coefficient.

In forward flight, rotor blades experience different conditions as they rotate. On the advancing side, forward speed adds to rotational speed and increases lift. On the retreating side, forward speed subtracts from rotational speed, and blade pitch must be increased to maintain lift. As airspeed rises, the retreating blade begins to stall and the pilot must add power to overcome the rising drag.

Retracted on the advancing side, the active Gurney flap is deployed on the retreating side to delay the stall. Covering the middle section of the blade, the flap locally improves lift and allows the outer section of the retreating blade to be offloaded. This reduces the power required to maintain airspeed and lowers fuel consumption and emissions, an overall goal of Clean Sky.

Flaps on rotors are not new. Kaman's helos have been using servo flaps as alternative to hub based actuators for years, but the application of Gurney flaps, along with their use to handle issues of the different lift modes and retreating blade stall, is new.

It's Nice to Know that Someone Has a More F%$#ed Up Defense Procurement Process than the United States Does

I am referring, of course, to the Republic of India, which has a long history of incompetent weapons development programs (Arjun tank, Kaveri engine, etc.) and corrupt foreign purchases.

We have one of the latter right now, with the India Ministry of Defense cancelling a helicopter purchase in response to a bribery scandal:

India has reacted to the scandal surrounding its purchase of 12 VVIP-roled AgustaWestland AW101 helicopters with the apparent cancellation of the €556 million ($776 million) deal.

In a statement posted late on 1 January on the Indian ministry of defence website, it says it has "terminated with immediate effect the agreement that was signed with AgustaWestland on 8 February 2010 for the supply of 12 VVIP/VIP helicopters on grounds of breach of the pre-contract integrity pact”.

Although the Anglo-Italian manufacturer had been pressing for arbitration talks to resolve the stalled deal, New Delhi has seemingly rejected this.

“Based on the opinion received earlier from the attorney general of India, it has been the view of the government that integrity-related issues are not subject to arbitration,” it says.

Nonetheless, there appears to be some ambiguity about its position until the country's attorney general offers a fresh opinion. "However, [AgustaWestland] has since pressed for arbitration and appointed an arbitrator from its side. In view of this [the ministry of defence] sought afresh the opinion of the attorney general. With a view to safeguard the interests of the Government, [it has] nominated Mr Justice BP Jeevan Reddy as its arbitrator."

………

A total of €51 million is alleged to have been paid as kickbacks by AgustaWestland to secure the order, an accusation strenuously denied by the company.

I have no clue why much smaller nations, like Israel and Sweden, manage to create sophisticated and effective weapons systems.

The Triumph of Wicked Stupid Ideas

It appears that the US Marines are to replace the C-2 carrier onboard delivery (COD) aircraft with the V-22, because increased orders should lower the unit price of the V-22 and allow the Marines more of the expensive, crash prone, and maintenance intensive dog.

The Marines have been very good at lobbying for really bad ideas lately, the EFV,^* adding STOVL to the JSF, and now, this:

“The C-2 makes us so much more flexible that we could support three separated groups, if necessary,” boasted Rear Adm. Marshall White, commanding air forces in the Western Pacific.

Faster-flying, longer-ranged and more capacious than the predecessor C-1 cargo plane, the ungainly C-2s and their crews were the unheralded heroes of the naval crises of 1968 and countless incidents since. Produced in a second batch in the 1980s and since upgraded, today a force of 35 C-2s based in key locations allows America’s 10 carriers to range the globe, waging aerial war and responding to diplomatic crises without planners having to worry about stranding the vessels beyond range of aerial resupply.

Rarely have so few airplanes of a single—and relatively unsophisticated—type been so vitally important to the conduct of a superpower’s global affairs. “The C-2A allows carriers and the fleet to maintain a ready position by supporting the vital supply line,” says Brian Scolpino, who oversees the C-2 force for the Navy.

But the Navy could end up retiring the C-2s and replacing them with a far inferior plane—one that’s not really a plane at all, but a controversial hybrid craft. The Bell-Boeing V-22 Osprey can take off vertically and cruise like an airplane thanks to its rotating wingtip engines, but lacks the C-2's far-flying efficiency and its ease of use rooted in nearly 50 years of institutional experience.

………

The Pentagon is no stranger to pricey, ill-advised weapons development scheme, but even in this wasteful institution the plan to scrap the C-2 stands out as especially self-defeating. America’s world-spanning carrier fleet is one of its key advantages over its enemies. Constraining the flattops’ resupply could force them to stay closer to their home ports, reducing Washington’s options in the event of war and diminishing U.S. influence during peacetime.

………

The Navy is well aware of the Cod’s enduring qualities. “The C-2A has not experienced any limitations as the Cod aircraft,” Scolpino writes. But concerted lobbying by the Marines and Boeing have practically forced the sailing branch to at least consider buying the V-22. If politics triumph and the tiltrotor takes the C-2's place, the fleet could find itself moving backwards in time, to a state of constrained fighting ability not unlike that that preceded the Cod’s arrival in 1966.

………

But the V-22 has less range and less payload than the C-2: Northrop’s prop plane can haul five tons of stuff 1,500 miles, but the V-22's range with the same load could be as little as 50 miles, according to Navy statistics and Bell and Boeing’s own literature. That’s in part because the V-22 has just over a third the internal space of a C-2 and in the case of bulkier supplies would likely need to haul them slung by a rope suspended from the fuselage—a huge source of drag.

………

Extending the tiltrotor’s flying distance would require the constant attention of Air Force aerial tankers, which can cost up to $10,000 per hour to operate. The V-22 is also slightly slower than the C-2, can’t fly as high because it’s unpressurized and costs more: $68 million for a new V-22 compared to an estimated $50 million for a new C-2.

Note that the Marines succeeded in delaying the CH-53K, which had been under budget and ahead of schedule, in order to secure more orders for the V-22 as well.

This is a complete clusterf%$#.

^*Full disclosure, I worked for General Dynamics, the prime contractor, on this vehicle when it was called the AAAV.

Sikorsky S-97, the Proposed Production Application of Advancing Blade Helicopter Technology, Enters Final Assembly

Fuselage is on its way to Sikorsky




3-view images are courtesy of Sikorsky

I've had an affection for this technology since the Advancing Blade Concept in the 1980s.

It's simpler than a tilt rotor and does things like autorotation and a lower disk loading, and I'm looking forward to seeing how it flies:

Sikorsky will begin final assembly of its S-97 Raider helicopter prototype this week, according to company officials.

That puts the helicopter manufacturer — which is competing for the US Army’s Armed Aerial Scout program — on track for a first flight at the end of 2014.

“It’s just a really exciting foundational milestone for us, and it’s great to be leaving the design phase of Raider and getting into the build phase,” Chris Van Buiten, Sikorsky Innovations vice president, said.

The Raider is based on the X-2 technology developed by Sikorsky in the late 2000s, but grows the size and weight significantly. Where the X-2 demonstrator was a one-person, 5,000-pound platform, the Raider will be roughly 11,000 pounds with room for six troops in its combat assault mode. In reconnaissance mode, that space could be used for extra equipment or ammunition.

Despite that growth, Sikorsky executives are confident the design will bring a mix of speed and maneuverability that helicopters have not yet achieved.

“This thing has to fly faster than 220 knots” at cruising speed, Van Buiten said when asked about key performance targets. “It has got to do more than a 3G turn at speed. It has to demonstrate hover at 10,000 feet and 95 degrees. Those are the non-negotiables.”

Hopefully, this will work better than the over priced and under performing bucked of bolts called the V-22 Osprey.

Another Day, Another Failed Military Procurement Program

The US Army has canceled the Boeing Hummingbird:

This month, the Army planned to deploy to Afghanistan an unusual new drone: an unmanned eye-in-the-sky helicopter programmed to use high-tech cameras to monitor vast amounts of territory. But now the drone might be lucky to be deployed at all, as the Army has moved to shut down production — possibly ending the program forever.

That drone would be the A160 Hummingbird, which the Army planned to equip with the powerful Autonomous Real-Time Ground Ubiquitous Surveillance Imaging System, or Argus. But earlier this month, the Army issued a stop-work order — one step away from termination — to the drone’s developer Boeing. The reason? A high “probability of continued technical and schedule delays,” costs and risks that have “increased so significantly that program continuation is no longer in the best interest of the government,” said Donna Hightower, the Army’s acting product manager for unmanned aerial systems modernization.

The A160 was set to be one of the Army’s most radical new drones. The chopper-drone could loiter for 20 hours at up to 15,000 feet, with a range of 2,500 nautical miles. It could observe up to 36 square miles, thanks to its Argus sensors. Also, Argus has a 1.8 gigapixel camera. Viewed through 92 five-megapixel imagers and 65 video windows for zooming in at ultra-high resolution, the the A160 drone would have been well-suited for spying on enemy fighters in vast and remote terrain like in Afghanistan, where three of the drones were scheduled to deploy this month. The A160 has also been sent on special operations workouts.

It appears that there were problems with the sensor suite, but perhaps more significantly, the aircraft experienced vibration problems during a flight test, and it's innovative variable speed rotor system was supposed to address this, so it puts the basic architecture in question.

Not Safety and Simplicity, Too Many Parts

So someone has decided that it might be a good thing to add even more moving parts to a rotorcraft:

A strange, 16-propeller vertical take-off and landing craft has been awarded the Lindberg Prize for Innovation at the Aero-Friedrichshafen 2012 airshow in Germany. It is an example of the unusual configurations made possible by distributed electric propulsion.

This is true. It is unusual.

It's also completely impractical.

There is not a single multi-engine aircraft that takes off with an engine out, and in this case, there are 16 engines that might fail.

If you lose an engine, you either don't take off, or, if you are in flight, you set down as soon as you can.

While this aircraft may (according to its inventors) be able to land safely with "several props failed", it won't make its destination with even one of the props failing.

Bad Day at the Office

Thankfully, there were no serious injuries.

Hotdogging at high altitude in a helo is not a good idea.

I'm Not Sure if These are Winglets or Stators

Click for full size

---

I Think that it's more of a stator than a winglet

Aviation Week has an article about looking at winglets to increase the performance of the V-22 Osprey (paid subscription required):

The ability of the Bell Boeing V-22 Osprey tiltrotor to fly farther, as well as faster, than helicopters has been a key factor in its fight for survival for more than a decade. But now, with both CV-22B and MV-22B versions recently pressed into service on longer-range, self-deployed combat and rescue missions in Libya and Afghanistan, the hunt is on for greater unrefueled performance.

Squeezing more range out of the V-22 is not easy, however. Constrained from birth by the need to fit on the restricted decks of U.S. Navy amphibious assault ships, the tiltrotor was necessarily limited to smaller-than-optimal wing and rotor dimensions leading to an inevitable impact on range. Without the options of increasing wingspan or rotor diameter available to them, designers are taking a leaf out of the Boeing Commercial Airplanes playbook and studying nacelle-mounted “sails” that work on the same principle as winglets.

Although Bell Boeing declines to comment on the development, Naval Air Systems Command (Navair) confirms it is preparing to flight test a modified MV-22 with the upgrade which could boost range by almost 5%. The concept, which was studied by Boeing for the Special Operation Forces CV-22 version as far back as 1994, harnesses the energy from the vertical upwash around the wing and nacelle. In the case of the V-22, Bell Boeing’s research indicates upwash angles of 10-20 deg. around the nacelles at the nominal cruise pitch attitude of 8 deg. The additional upwash velocity produces a propulsive force by tilting the lift vector forward.

I should note that I am not an aerodynamicist, but it looks to me a lot of the gains from these surfaces are from straightening the rotational wash off the props, much in the same way that stators do in a multi-stage turbine.

Because it increases effective wing area, it would have the effect of reducing longitudinal stability, so the flight test regime will target this concern.

Sikorsky Says X2 Technology Does Not Scale Beyond Medium Lift

Any helo folks out there who can explain this:

Sikorsky's breakthrough X-2 high-speed helicopter likely can't be scaled up to the size of a heavy-lift helo, a Sikorsky executive told reporters Sept. 14.

"There is a question on the scalability on the X-2 technology at the medium class," said Scott Starrett, Sikorsky's vice president for government business development. "When you get to the utility-medium or attack-medium class, it scales nicely." However, with size and weight increases "you starting getting up to that kind of payload and physical size and it gets to be a different challenge for the technology."

Starrett said that the company's CH-53K, which Sikorsky is developing for the U.S. Marine Corps, could fit into the Defense Department's Joint Multi-Role (JMR) requirement for the heavy-lift helicopter.

Certainly, one explanation here is that Sikorsky is big on the CH-53K, which is under budget and ahead of schedule, but under threat from the V-22 mafia, who see it as a threat (it equals or bests the V-22 in everything but speed with less deck space and lower cost), and they don't want this as a distraction.

The other alternative is that coaxial rotors simply do not scale well.

When one looks at large twin main rotor helicopters, the Chinook and the (huge) Mil MV-12, it seems that spaced, rather than coaxial or intermeshing (Kaman) rotors are the architecture of choice.

Sikorsky X2 Makes Final Flight of Program

Considering that it was developed with private money on a shoe string, the program has had some fairly remarkable accomplishments:

• Achieving a cruise speed in level flight of 253 kts, a record.
• Doing so while maintaining the low speed and hover performance of a conventional helicopter. (as compared to the performance of the V-22 in those areas, which is just pitiful)
• Doing so at noise and vibration levels equal to or lower than current helicopters.

Sikorsky will not be moving onto developing the S-97 light attack/scout helo.

Sikorsky X2 Wins Collier Trophy

Click for full size

---

Demonstrator


Commercial variant


Assault and utility


Search and rescue


Attack

The award of what is arguably the most prestigious award in aerospace is well deserved.

They have validated that their advancing blade concept helicopter can work, and work without the workload or vibration issues that bedeviled its predecessor in the 1980s, and they have done so on a relative shoestring.

It appears to have most of the advantages, and none of the disadvantages of tilt-rotor technology.

Another Day, Another VTOL Concept

Click for full size

---

Nice try

It's a fan in wing concept, with 4 fans and 2 thrusters, (Videos at link) better known as a bunch of complex moving equipment that can fail at an inopportune time.

Remember, you don't just have the fans,. you 6 fans, and their associated transmissions, plus shutters and vanes for control in VTOL mode, as well as thick low aspect ration wings which don't have space to carry things like fuel, because they have the fans.

Call me a cynic, but I do not see success here.

Unconventional Helicopter Developments

250 kt record breaking flight, complete with Pr0n film^* music soundtrack


The EADS X3


And their EADS/Eurocopter video


X2 Raider Mockup


The X-2 Raider, blissfully music free

Graham Warwick gives a survey of new technologies that might find their way into the Joint Multi Role (JMR) rotorcraft program, along with the video of the X-2's record breaking flight (top)


Meanwhile, EADS is flight testing its X3 (I wonder where they got that name) compound helo, which uses dual wingtip props, and it provides anti-torque by varying the pitch of the thrusters.

It's far less ambitious than that of the X-2, but their selling point is reduced life cycle cost, which is probably more a shot at the expensive tilt-rotors out there than the X-2 advancing blade concept, which really doesn't seem particularly different in the amount of bits that move.

One interesting twist is that the X3 will slow its rotor at higher speed, reducing drag, though I could see this added to an advancing blade helicopter as well, particularly if the aircraft has a wing.

My quick look at the demonstrator indicates that it is not a particularly useful helicopter.

With two props about a yard from where the entrance to the passenger/cargo area is, both loading and unload, as well as the use of a winch for a rescue mission, would appear to me to be highly problematic.

Of course, the X3 is a demonstrator cobbled together with bits of various existing helicopters, so an operational version would likely address these shortcomings.

Sikorsky is also pitching a replacement for the OH-58D, theS-97 X2 Raider, which is rather similar to the MI-24 Hind or the Augusta/Westland Lynx concepts for an attack helicopter which retains transport capabilities or the ability to carry its own reloads.

^*Not that I'd know what pr0n movies' sound tracks actually sound like.^†
†Not that there is anything wrong with that.

Sikorsky X2 Sets Unofficial Speed Record

The helicopter has reached speeds in excess of 250 kt (460 km/h) in level flight, besting the official record of 217 kts set by a (then Westland) Lynx, and the unofficial record set by its predecessor, the XH-59A demonstrator, of 236 kts.

It also appears that it could achieve a speed of 265 kts with the addition of a "sail fairing" between the two rotors.

It's unclear to me, however how this is a helicopter speed record, and not a compound helicopter speed record, since the tail thruster makes a significant difference in just how power is applied at higher speeds.

I was under the impression that either a wing or a horizontal thruster made it a compound helo, but it appears that the definition being used here is that it's specifically the wing that makes it a compound helicopter.

The Fed Gets Grimmer

Well, the minutes from the Federal Reserve's June meeting of the Federal Open Market Committee (FOMC) have been released, and the already grim predictions that they have made for GDP and employment have become even grimmer.

It's time to crank up the helicopters, and literally begin dropping money out of them.

I've run the numbers for this operation, and it would require fewer than 100 of the whirlybirds to accomplish the task.