Bell/Boeing V22 Osprey & consorts

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

Vi, absolument.
Mais bon, ils mettent bien des B-52 alors

Tuckson a écrit

Question : quelles sont les dimensions d'un ascenseur de PA ? C'est bien plus petit, non ?

Honte à toi, Grand Commandeur Suprême !

http://www.avions-militaires.net/dossiers/bateaux/cvn-71-roosevelt.php

Bah alors, c'est quoi ça ?

Des ascenseurs ? Oups désolé…

Regarde en bas, tu as les "mensurations" des ascenseurs. Ceux des Américains supportent 40 T (à cause du Tom' )…

http://fr.wikipedia.org/wiki/Clemenceau_(porte-avions)

Tuckson a écrit

Le V-22 fait 5.61 m de haut avec les rotors en position horizontale soit 3 cm de plus qu'un E-2, et pas moins de 25.55 m d'envergure (soit 1 m de plus qu'un E-2 qui peut replier ses ailes) : là, par contre, c'est énorme.

Question : quelles sont les dimensions d'un ascenseur de PA ? C'est bien plus petit, non ?

EUH SOnny

Le V-22 est egalement repliable

==> VOIR PHOTO

Heureusement, nous partisans du V-22, avons paré à tout

http://www.navair.navy.mil/v22/?fuseaction=gallery.main

Plein d'images, dont celle-là :
http://www.navair.navy.mil/v22/img/gallery/image.ashx?image=USS%20Bataan%20Overhead%201_4-sm.jpg&width=550 et celle-là http://www.navair.navy.mil/v22/img/gallery/image.ashx?image=v22_088.jpg&width=550

En gros, ils n'iraient pas en soute mais alors du coup, ils ne peuvent plus utiliser le porte-avions pour les autres appareils (ou alors, il faut faire décoller les Osprey pour faire décoller les autres )

Ca a d'la gueule

pilou a écrit

En gros, ils n'iraient pas en soute mais alors du coup, ils ne peuvent plus utiliser le porte-avions pour les autres appareils (ou alors, il faut faire décoller les Osprey pour faire décoller les autres )

Ca, c'est pas grave car c'est un porte-helico (USS Bataan LHD5) et pas un porte avion. Je sais il est aussi grand que le Charles de Gaulle

Bizarre, car il y a effectivement plusieurs photos d'une version "compacte" :
http://en.wikipedia.org/wiki/V-22_Osprey
http://en.wikipedia.org/wiki/Image:V-22_Osprey_wing_rotated.jpg
Légende de la photo : "First production Osprey to join the V-22 Navy flight test program since resumption of flight evaluations in May of 2002. Aircraft is shown in compact storage configuration."

On remarquera cependant la mention Marines. ET je pense que c'est l'explication. Les V-22 sont destinés à être embarqués sur les futurs porte hélicoptères américains (qui possèderont des JSF d'ailleurs, où est la notion de porte hélicoptères là-dedans ).
Source : Ici
Donc peut être sont-ils destinés à rester sur le pont d'envol ? Etant donné que ce sera du matériel estampillé US MARINES, ils ne seront pas assimilés à du matériel US NAVY et seront dès lors laissés sur le pont, les capacités VSTOL des JSF (US MARINES) résolvant le problème ?

Ou alors, ils vont arranger les ascenseurs, etc, pour permettre leur stockage.
D'autres infos :
http://www.boeing.com/rotorcraft/military/v22/docs/V-22_overview.pdf

Vi. Surprenant d'ailleurs. Toutefois, je serai bien intéressé de voir les futures versions embarquées, dans le sens réel du terme : pas sur le pont d'envol et faire un embouteillage monstre
En plus, je vous raconte pas le soucis en cas de vagues scélérates (z'avez vu la transition vers un sujet hautement intéressant fait par votre serviteur ).

la classe de navire amphibie comme leTARAWA ou WAPS seront remplaçé par le futur LHA, spécialement conçue pour accueillir le F-35 et le V-22.

les dimensions seront donc étudiées pour accueillir les futurs appareils, notament au niveau des ascenseurs je pense.

c'est northrop grumman qui a remporté le contrat et a lance les études prélémianaire pour un coût de 108.9 millions de dollars

futur LHA (R)

autre projet de LHA:
http://www.exwar.org/Htm/5000PopD3.htm

Quelques news ===> (2 textes)

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1) une réponse point par point aux prétendues carences du V-22 Osprey, avec l'étalement de ses capacités (long mais très intéressant).

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The Right Perspective

by Maj Jeffrey P. Hogan JANUARY 2007

Departing the tanker with full fuel tanks, the MV–22 from Marine Medium Tiltrotor Squadron 162 (Reinforced) throttles back to maximum endurance airspeed. At 14,500 feet above sea level the aircraft is high above the threat and burning fuel ever so slowly—slow enough to remain on station for another 31/2 hours without additional refueling. Line-of-sight communications is crisp at this altitude, complementing the integrated satellite communications capability. The relative calm of this casualty evacuation (CasEvac) platform relaxing at altitude (the engines are operating at a mere 38 percent of capacity) is in sharp contrast to the situation below.

When the call comes in the crew knows the seriousness of the situation without asking. As the fastest evacuation platform in theater, most of the CasEvac missions they receive are focused on patients who have no time to spare. Immediately plotting the evacuation site on the digital map, the crew slews the forwardlooking infrared sensor to the landing site near the point of injury. Even from this altitude the thermal signature of a burning coalition vehicle is easy to break out of the scene. With the copilot still copying the CasEvac brief, the flying pilot begins the descent and turns inbound to the landing zone (LZ) at 300 miles per hour. Although the aircraft can range any zone within 70,000 square miles in less than 30 minutes, this will be a relatively short trip of only 75 miles—15 minutes for the Osprey.

Continuing the descent at maximum speed, the crew confirms the configuration of the aircraft survivability equipment and checks the readiness of the ramp-mounted M240. Based on the threat, the crew opts for a low-level ingress and levels off about 10 miles from the LZ at 200 feet above ground level. In an effort to reduce exposure, the crew maintains 220 knots until just 2 nautical miles from the zone. As they throttle back to prepare for landing, the reduction in engine thermal signature makes engagement by heat seeking missiles even more difficult for the enemy.

Half a mile from the zone, the aircraft receives fire from a nearby building. The components in the left nacelle, which have been hardened to withstand direct hits from 12.7mm ammunition, continue to function normally. Nearby hydraulic lines do not fair as well and are compromised during the engagement. Instantaneously and without crew action, the triple redundant flight control computers and vehicle management systems isolate the leak and reroute hydraulic power to critical flight controls. The crew, feeling a slight transient, notes the failure and decides to continue for the landing.

As the casualty is loaded, the crew confirms the status of the aircraft using the cockpit management system and prepares for takeoff. In order to expedite their departure, the crew rotates the nacelles forward before lift-off to maximize acceleration after becoming airborne. Passing through 30 knots the aircraft again receives fire from a nearby rooftop—this time in the form of a salvo of rocket propelled grenades. While two of the rockets pass under and behind the aircraft, the third strikes the right nacelle just forward of the engine compartment. Consequently the engine fails when it ingests debris from the shattered intake. The cockpit crew executes its procedures as the crew chief engages with the ramp gun. Fortunately, the aircraft needs little more than 40 to 50 knots of forward speed at this altitude to fly away on a single engine. The left engine, now required to drive the entire rotor system, feeds torque to the failed engine’s rotor through a backup cross-shaft connecting the two transmissions. As the nacelles rotate forward, the burden on the good engine decreases considerably as more of the aircraft’s weight is borne by the wing.

Up and away from the threat, the aircraft turns not for the battalion aid station but directly for the Level 3 treatment facility 50 miles farther away. Even with the failed engine the Osprey can cover the distance in nearly half the time of a conventional (undamaged) helicopter. After completing a slight rolling landing to the treatment facility, the crew relays a safe on deck call to its base via another squadron aircraft that has just arrived on the tanker to pick up CasEvac standby for the remainder of the night.

While an elegant depiction of the Osprey’s future worth in combat, the narrative above has a hollow ring to it. Somewhere in the reader’s subconscious the scenario is being compared to the distant echo of all of the others contrived over the years to make the case for the MV–22. It’s a standard recipe; get the audience to buy your scenario and then plug the system you advocate into it for maximum effect. Of course, in some far-off parallel universe the crew is not as sharp, the enemy is luckier or better equipped, or maybe the Osprey just doesn’t live up to expectations. Scenarios are informative, but none are definitive. For each one that proves a concept, another can easily be constructed to immediately disprove it. Scenario models also tend to be intellectually confining, inviting us to fight the last war rather than the next. Ask yourself, were you thinking about Iraq when you read the CasEvac example above?

A better way to think about the potential of tiltrotor technology is to first separate fact from myth. People are entitled to their own opinions, but they are not entitled to their own facts. The discussions below are intended to arm the reader with some ground truth about this aircraft. However, there are simply not enough pages in this magazine to clarify every bit of bad information orbiting the V–22 program. Questions will remain. Anxiety will continue. But healthy skepticism, based on reality and truth, is far preferable to cynicism founded on rumor and myth.

Folklore Management
Myth. The V–22 has poor survivability characteristics.
Fact. Survivability consists of susceptibility, vulnerability, and crashworthiness. Put another way, your chance of survival depends on not getting hit, being able to fly if you do get hit, and (if you get hit badly enough) controlling and surviving the crash.

The V–22’s range and speed increase the crew’s ability to avoid threat areas entirely and still accomplish the mission. Even in a threat area, the susceptibility of a V–22 flying at 240 knots and 200 feet above the ground is far less than a helicopter flying half as fast. For an enemy to engage an aircraft he must detect, identify, track, fire, and (in some cases) control a weapon in flight. The increased speed of the V–22 reduces the time available for the enemy to get a weapon into the air before the aircraft leaves the engagement envelope. Even in multiship formations, the V–22 can maintain this high speed until just a few miles from the LZ. From this point the Osprey is a little over 1 minute from landing—a narrow window for the enemy to engage even though the aircraft is slowing down. The integrated suite of aircraft survivability equipment is able to automatically detect missile launches and dispense countermeasures while the crew maneuvers. Combined with the low infrared signature of the V–22, these countermeasures are particularly effective in defeating shoulder-fired heat seeking missiles.

But what if the aircraft is hit by enemy fire? How vulnerable is it? The MV–22 has undergone an extensive live fire test and evaluation (LFT&E) program consisting of no less than 60 test events and totaling more than 592 ballistic test firings (more than any aircraft in Department of Defense history). All flight control actuators were proven to be resistant to light antiaircraft artillery armor piercing incendiary (API) at 90 percent muzzle velocity. During tests of the wing structure, multiple 23mm (API and high-explosive incendiary (HEI)) shots failed to compromise the load carrying integrity of the wing. Portions of the structure were actually determined to be invulnerable to all API and HEI projectiles up to and including 23mm. Overall the LFT&E effort determined that the probability of an aircraft kill (given a hit) was significantly less than that of existing helicopters.

What about failures subsequent to the initial ballistic impact? The use of nitrogen inerting in the fuel tanks reduces the probability of fires and explosions. A fire suppression system in the wing is capable of extinguishing a fire automatically and within microseconds. The vehicle management system can isolate a hydraulic leak within a few tenths of a second to reduce the amount of fluid that might feed a fire to approximately one quart. Engine tests have shown that the AE1107C Liberty engine can run for as long as 5 or 6 minutes without engine oil. The emergency lubrication system is capable of providing oil to the transmissions for 30 minutes in the event the primary system fails. The wide separation between the two engines on a V–22 reduces the possibility that a single shot could damage both engines. The single engine capability of the aircraft is also considerable, and the V–22’s unique ability to transition to airplane mode reduces the load on the good engine significantly.

Okay, all of that stuff didn’t work. We got hit and the damage is so severe we can’t continue flying. What now? The design of the V–22 places the mass of the major components (engines, transmissions, coolers) at the wing tips as opposed to right over the passenger compartment as in conventional helicopters. The wing box is designed to shear the wing (and the high mass components) away on impact and protect the cabin section. The composite blades are designed to “broomstraw” after contact with the ground to further reduce any possibility of cabin intrusion. Passengers are seated with a five-point harness a stroking seat designed to absorb a 13.5 G (gravitational acceleration) impact. The use of suction pumps to transfer fuel up to the wing tanks means that there are no pressurized fuel lines in the cabin to spray on passengers following impact. The self-sealing fuel cells have been drop tested and contain breakaway fittings to reduce the possibility of a postimpact fire. The bottom line is that your chances of surviving an enemy engagement are far better in a V–22 than in any conventional helicopter in the Marine Corps.

Myth. The V–22’s size and down wash limit the number and type of feasible LZs.
Fact. There seems to be some confusion about the size of the V–22 relative to the CH–46. The CH–46 is 84.33 feet long by 51 feet wide. The Osprey is 84.58 feet wide and 57.33 feet long. It’s bigger but only marginally. Additionally, it should be selfevident that the increased range and speed of the V–22 greatly increases the number of feasible LZs. This issue of fewer zones isn’t just a myth; it’s completely inverted from reality.

Another often cited concern is the down wash of the V–22 and the ability to land in dusty zones. To be sure, the down wash of a V–22 is greater than that of a CH–46. (The Osprey weighs more than twice as much and has only 58 percent of the rotor disk area.) But does this mean that the aircraft can’t land in the dust? No. Anyone who has ever landed a helicopter in the dust can testify to the skill required to do it safely and consistently. In most cases, visual reference with the ground is lost at some point prior to touchdown. The generic technique is to set a landing attitude (with deceleration and rate of descent under control) prior to losing visual contact with the ground and letting the aircraft land. This technique also works in a V–22, although visual reference is normally lost at a higher altitude.

However, the V–22 also has equipment and features to assist during reduced visibility landings that no other Marine Corps helicopter has. For instance, each of the three inertial navigation systems contains a highly accurate ring laser gyroscope to resolve velocities down to fractions of a knot. These precise velocities support the current hover coupled capability that can be used to automatically hold the aircraft over a point (hands off ) or land on that same point without visual reference to the ground. Even for a hand-flown landing, the hover page in the V–22 gives the crew a situational awareness about drift and position over the ground that is unprecedented in our history.

Myth. The V–22 lacks a defensive weapons system.
Fact. The first MV–22 deployments will be made with an M240 ramp-mounted weapons system. This system has the capability to fire both on the ground and while airborne with a 180-degree field of fire. Work continues within the program to procure a permanent defensive weapons system to either replace or complement this interim solution. The goal, based on the Capabilities Production Document for Block B, is to field a system capable of firing into all quadrants (a significantly improved field of fire compared to legacy helicopters).

Myth. The V–22 is not maneuverable at low airspeeds. (Specifically, it cannot descend as fast as a helicopter.) Fact. Figure 1 depicts the allowable rate of descent at given airspeeds for the V–22 versus other Marine Corps helicopters. While helicopters must restrict rate of descent to 800 feet per minute at 40 knots, the V–22 is capable of 1,700 feet per minute at the same speed. Additionally, only the V–22 has a warning system to alert the crew of a high rate of descent situation at low forward airspeed. Testing has also shown that tiltrotors are able to recover from a high rate of descent situation as fast (if not faster) than conventional helicopters. Low speed, high rate of descent profiles have been (and will remain) a hazard to rotorcraft. Contrary to popular mythology, the associated risks will actually decrease once the V–22 is fully fielded.

Technology Doesn’t Win Wars, Marines Do

Nothing stated above guarantees anything. No test, regardless of scope or complexity, can perfectly simulate today’s battlefield (or tomorrow’s). Ultimately, the enemy gets a vote. And of course, not all of the news is universally good. Almost no one is satisfied with the ramp-mounted weapons system as anything more than an interim solution on the way to something better. The lack of weather radar reduces the V–22’s potential significantly. The current coupled approach to a hover terminates at 50 feet, which most believe is too high. The electronic warfare suite could be better integrated into the cockpit controls and displays. More expendables would be a welcome improvement. Such is life. More importantly, such is life in every other weapons program. These issues and others are getting attention at the appropriate levels, and improvements are (slowly) making their way to the Operating Forces.

In the meantime, what should be the source of confidence in the V–22? The answer is simple—people. Marines should rest assured that people just like them, those who share their concerns, values, and experiences, work hard every day to make sure the V–22 will be at the right place, at the right time, with the right tactics, to get the job done. The CH–46, CH–53, UH–1, and AH–1 are not successful because they are great aircraft. They do not post phenomenal readiness rates because they are inherently well designed. They do it because people work incredibly hard to keep the aircraft ready to fly. These communities do not keep combat losses low because of perfect systems but, rather, because of great flight leaders and crews who know how to exploit the strengths and guard the weaknesses of their aircraft.

The V–22 will be no different. The people in this program, the ones who identify and solve problems every day, are people just like you. They are Operations DESERT SHIELD/DESERT STORM, Operations ENDURING FREEDOM/IRAQI FREEDOM, and Horn of Africa veterans—many highly decorated for their actions in combat. They are experts in their legacy aircraft—most are weapons and tactics instructors. They are graduates of the resident and nonresident schools of our own and sister Services. They include Air Force personnel with impeccable credentials in special operations. They are professionals all and profoundly committed to their mission.

What Is Past Is Prologue

This program is controversial. The skepticism harbored by many Marines toward the V–22 is understandable and not entirely unhealthy. But in our zeal to explore every issue and identify every challenge, too much of our energy has been spent sitting in judgment of the past. The time to argue whether tiltrotor technology is worthy of our investment is over. The time to conjecture over the value of alternatives like the H–60 or a service-life extension for the CH–46 is long past. Spirited deliberation and debate can be constructive. But deliberation and debate without end is pernicious. In the case of the MV–22, we often end up arguing about how the aircraft got here rather than where we’re going to take it. It’s time to face reality. It is here.

The changing face and pace of conflict is another reality we are confronting at a time when our Armed Forces seem to be shrinking. Distributed operations will continue to move from the theoretical to the absolutely essential. Certainly the MV–22 is not the answer to every tactical problem, but it can increase the raw productivity of an important warfighting function. How do we integrate and exploit such a potentially disruptive technology as our doctrine evolves? The question isn’t how to get an MV–22 to do what helicopters do now, but how to do assault support better across the spectrum of conflict. The question isn’t how to simply subtract the CH–46 from our force structure and add the V–22 in its place, but how to move this function of Marine aviation so far forward that all of the others benefit. Maybe the better question is whether we need toconfine the MV–22 to an assault support “box” at all. We have tackled technology insertion issues like this before (global positioning system, laser guided weapons, and night vision goggles all come to mind), and we will be forced to again in the future (expeditionary fighting vehicle, lightweight howitzer, Joint Strike Fighter). These are the questions that require the attention of the best and brightest in our Corps.

If you are wearing the uniform today you will be part of finding the answers.
Your input will be based on your experiences and rightly so. But you will also be asked to put your own biases, passions, and emotions in perspective—to see the future the way it can be, as opposed to where conventional wisdom would predict. You’ll recognize the importance of avoiding words like “always” and “never” when discussing tactics. You’ll grow beyond the world of the here and now and start thinking about the next generation of Marines who are relying on you to lay the foundation for victory on the battlefields of the future. In the end you might even conclude that the only real problem we face is that we can't find a way to by MV-22s faster.


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2) D'autre part, voici un article relatant l'entraînement d'unités de l'armée U.S avec des V-22 Osprey

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'Osprey' squadron gives Army's 3rd ID a boost

By Cpl. Jonathan A. Tabb, MCAS New River

FORT STEWART, Ga. (Jan. 10, 2007) – In anticipation of their possible deployment for Fall 2007, Marine Medium Tiltrotor Squadron 263 conducted familiarization training with the Army soldiers of the 1st Brigade Combat Team, 3rd Infantry Division Jan. 9.

The Marines offered nearly 100 soldiers from the 5th Squadron, 7th U.S. Cavalry and 1st Battalion, 41st Field Artillery a chance to become familiar with loading and flying in the MV-22 “Osprey,” by breaking into five groups and taking turns flying in the aircraft.

Sgt. Maj. Grant VanOostrom, VMM-263 squadron sergeant major, said he was pleased with the event and its results.

“The joint training with VMM-263 and elements of the First BCT went extremely well,” he said. “It gave us the opportunity to showcase and discuss the MV-22B to other service members within (the Department of Defense). By conducting static displays, discussing egress procedures and participating in familiarization flights, members of First BCT were given the opportunity to become familiar with the Marine Corps’ newest aviation platform.”

Many of the Soldiers expressed apprehension with the idea of riding in an unfamiliar aircraft.

“My concerns were laid to rest when we got off the ground.

It was absolutely awesome,” said Spc. Brent Cossich, Brigade Colonel’s Personal Security Detachment Team combat medic.

According to Capt. Danny J. Cohlmeyer, VMM-263 aviation safety officer, the training was important because soldiers will likely see the aircraft in a combat zone in the near future.

“The ‘Osprey’ is going to become an asset and be used by everyone,” he explained. “They need to know the sounds, smells and the sensations of being inside this aircraft.”

The squadron supplied two MV-22 “Ospreys” for the training evolution which lasted from 1 until approximately 3 p.m.

VanOostrom said he and each of the squadron Marines present appreciated the support his unit received from the soldiers at Fort Stewart.

“The importance of the training between VMM-263 and the First BCT was well supported by the Army, specifically the 5-7 Cav. and 1-41 FA.,” he said. “The First BCT commander, Col. John Charlton, even made time to come out to see the aircraft and participate in a (familiarization) flight.

“Talking with him after his flight I could tell he was already a supporter of the MV-22B and that he recognizes the benefits it will bring to the fight in the Global War on Terrorism.”
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Je suppose qu'ils vont seulement remplacer les Tarawa's directement. Car les WASP's sont assez récent:
Tarawa
http://www.fas.org/man/dod-101/sys/ship/lha-1.htm

WASP
http://www.fas.org/man/dod-101/sys/ship/lhd-1.htm



PS: mauvaise nouvelle pour les Osprey
http://www.flightglobal.com/articles/2007/02/09/212000/us-marine-corps-grounds-all-46-mv-22-osprey-tiltrotors-after-flight-control.html

Ospreys start to fly, but most still grounded

L'informatique embarquée semble avoir quelques problèmes récurrents…

Et si effectivement, il y a des problèmes à certaines températures, très froides, comme le dit l'article; on pourrait raisonnablement penser qu'il puisse y avoir des problèmes à très haute température…

Embêtant en opération.