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KC135 Tanker

Poncho (Admin)
Poncho (Admin)
Whisky Charlie

KC135 Tanker Empty KC135 Tanker

Message par Poncho (Admin) Mer 16 Sep 2009 - 14:23

Bonjour à tous

L'appel d'offre sur les nouveaux tanker s'éternisant... les bon vieux KC135 restent sur le pont

Un long article détaille les challenges...

http://www.aviationweek.com/aw/generic/story.jsp?id=news/TANK091509.xml&headline=USAF Worries About Refueler Repair Costs&channel=defense


USAF Worries About Refueler Repair Costs

Sep 15, 2009

By Amy Butler
Scott AFB, Ill.

The mother of the last KC-135 pilot has probably not yet been born.

So says former Air Mobility Command (AMC) chief Gen. Duncan McNabb, who led the U.S. command that oversees the airlift, refueling tanker and aeromedical evacuation aircraft from 2005-07. He now heads the Transportation Command, which includes ground cargo and sealift.

As a result of a series of bad oversight decisions by the Pentagon and Congress, procurement mismanagement and politicking on the part of would-be tanker contractors and lawmakers eyeing work for their districts, there appears to be no more clarity now on the way forward to modernize the fleet—whose average age is 45 years—than there was in 2001.

Meanwhile, at AMC, planners are wrangling with how to keep the KC-135s flying until as late as 2043. “We have tremendous maintainers and air crews, so I am not concerned in the next few years about how the KC-135 performs,” says Gen. Arthur Lichte, outgoing AMC chief. Lichte points out that maintenance crews sometimes work 7 hr. for every hour of KC-135 flight. Gen. Raymond Johns will replace the retiring Lichte this year.

Refuelers—critical elements of U.S. military strategies—are needed to quickly deploy combat aircraft overseas in the event of war. To sustain such operations as those in Iraq and Afghanistan, tankers enable fighter and intelligence aircraft to fly beyond the limits of their fuel tanks. Additionally, future war plans, especially those addressing threats from North Korea and China, rely heavily on tankers because of what strategists call the “tyranny of distance” in projecting forces across the vast expanse of the Pacific Ocean.

However, without new tankers to replace old ones, anticipated costs to continue the mission are growing dramatically. “Every year we don’t get tankers, it is costing us $55 million right off the top,” Lichte says. “When you get out to about 2018 and 2020, what started out as about $2 billion a year to maintain the KC-135 fleet goes all the way up to $6 billion.”

This spike in maintenance charges has AMC planners worried. U.S. Air Force officials anticipate spending about $3.5 billion per year from its procurement account buying new KC-X tankers for the foreseeable future, and this amounts to 12-18 aircraft per year with an estimated per unit cost of $200 million. This means a significant portion of the Air Force’s budget for the next couple of decades will be designated solely for the refueling mission. Assuming $6 billion in annual maintenance cost for the KC-135 fleet, plus another $3.5 billion to buy KC-Xs, the yearly cost of the refueling mission is projected to exceed the total annual budget of the Missile Defense Agency at its peak during then-President George W. Bush’s administration.

The increase in projected maintenance costs is attributable mostly to planned improvements to keep the fleet safe. Dave Merrill, AMC’s deputy director of strategic plans, programs and requirements, says two areas of concern are behind that estimate. “We know that there will be needed depot-level maintenance actions on fuselage skin and wiring,” he says, noting that this amounts to a “mountain of requirements” late in the next decade.

“Obviously, the biggest fear is a catastrophic failure,” Lichte says. “We want to make sure we prevent that. And, so we continue to do everything we can to make sure don’t have an Aloha Airlines where the skin peels back or a TWA 800 [type incident] where frayed wires cause an explosion in the fuel tank.” Lichte says the “unknowns” of flying a fleet of half-century-old aircraft worry him.

Corrosion management remains a primary focus for the KC-135 fleet. As much as 30-50% of the programmed depot maintenance addresses corrosion issues, AMC officials say. In total, aging-related costs are expected to add at least $17.8 billion to the price of maintaining the KC-135 for 40 years. This is the equivalent of about five years’ worth of KC-X procurement at the $3.5-billion annual estimate.
For day-to-day KC-135 maintenance, much of the attention is placed on managing the fuel tank systems, cockpit instruments, flight control systems and auxiliary power units, says Col. Thomas Kauth, maintenance division chief for AMC’s logistics office.

Gaining access to preferred global air routes with the appropriate avionics is also an issue for the refueling fleet. The Block 40 upgrade, which adds the Global Air Traffic Management modification, is nearly complete on the KC-135 and a CNS/ATM modification (Block 45) will follow, AMC officials say.

A request for information issued last fall for an avionics modernization program (AMP) has kicked off a similar upgrade for the KC-10. All of the Air Force’s 59 KC-10s must have this upgrade by 2015 to use preferred air routes, which are more direct and in altitudes that offer better efficiencies.

Lichte says he is optimistic the AMP program can be executed by the 2015 deadline. “You may not be able to go into some of the key airfields in some of the big cities in France or Germany—even in the Pacific—but you can do workarounds for some of the C-130s [which also require an AMP],” Lichte says. “But, you are not going to be able to do that with some of the KC-10s to do some of the refueling missions that are going to be in some key spots or to pick up cargo. It is very urgent with the KC-10s.”

The AMP will also address ongoing problems with component ­obsolescence.

The KC-10 is expected to remain flying until at least 2045, but access to replacement parts is a worry. “Complete and accurate technical data exist for the areas on the aircraft manufactured by McDonnell-Douglas, but vendor-built items often are discontinued or become obsolete, often with little notification to the original equipment manufacturer,” according to a December 2008 servicelife-extension study for the KC-10. “For these components, there is generally insufficient technical data to provide to alternate vendors.”

Kauth also says the KC-10 boom control unit is becoming unreliable and should be replaced.

Already, the KC-135 fleet has undergone re-engining efforts. A-models, used by the active duty forces, were upgraded to the KC-135R/T version with CFM56 turbofan engines, increasing thrust from 11,000 lb. per engine to more than 21,000 lb. This led to a 25% increase in fuel efficiency, a 50% boost in fuel off-load capability and a 25% decrease in operating cost, according to AMC officials. The first KC-135R/T entered service in 1984 (the only difference between the two is in the T, the main body fuel tank is separate from those in the wing, where the KC-135 draws engine fuel). Additionally, the Air National Guard began receiving the first KC-135E with the addition of new TF-33-PW-102 turbofan engines in 1982, providing 14% more fuel efficiency and 20% more fuel off-load capacity. The command is also trying to balance out the number of hours on each KC-135; the aircraft with the fewest has about 14,370 hr., less than half the most heavily used KC-135 at 33,977 hr.

AMC planners hope that if the KC-X program takes off and manages to begin delivering aircraft in the next few years, they can begin a cost-avoidance strategy by aggressively retiring KC-135R/Ts; 13 remaining KC-135Es should be retired by the end of the month.

“When you are talking more than 500 tankers in the inventory, it is going to take a long time to recapitalize. You know you are going to have some airplanes that are going to get out into the 70-80-year time frame and you know you’ll have to take action to keep those airplanes flying,” Merrill says. “If I can avoid some of that by early recapitalization, I will save dollars.”

AMC has explored introducing as many as 30 KC-Xs into the fleet per year, a number Merrill acknowledges is optimistic given budget limitations at the Pentagon. “The higher you go, the more you save even though the more you pay upfront, because you are avoiding those costs of maintaining 60-year-old airplanes.”

“I am really concerned when you start thinking we are only going to buy 12 aircraft per year,” Lichte says. To buy the 179 anticipated KC-X tankers, this would require about 15 years, and at least another 25 years to replace the entire fleet of 415 KC-135R/Ts in the Air Force inventory now.

Based on the most recent mobility requirements document, AMC must maintain 520-640 refuelers in the fleet. Today, a total of 474 KC-135s and KC-10s are in the fleet, so Merrill says the command is operating “in somewhat of a bathtub.”

The total requirement could change, depending on the outcome of two major studies that should be complete by year-end. The Quadrennial Defense Review will dictate the military force structure needs moving forward based on what fighting construct the Pentagon chooses. Senior Pentagon officials have indicated it is unlikely a force structure will be maintained that could fight two nearly simultaneous wars. However, Lichte says mobility forces are less dependent on this model for sizing than, for example, the aerial combat fleet (which depends largely on the number of air battles expected). This is because the tanker fleet is needed to support a variety of missions, including homeland emergencies, humanitarian crises and everyday cargo transfer.

The planned 179 KC-135 replacements are only the start of a larger recapitalization. The Air Force has maintained for years a three-pronged strategy: KC-X, KC-Y and KC-Z. “KC-Z has always been the shock absorber,” Lichte says. “If we have already met the requirements, then we won’t need to get a KC-Z.”

AMC is also looking far ahead to a day when unmanned aerial refueling will be a reality. Today’s UAV fleet—mostly Predators, Reapers and Global Hawks—does not aerial refuel. However, the Air Force Research Laboratory is managing a program to test automated aerial refueling with a KC-135 and simulated unmanned combat aircraft. It includes trials with simulated fighter- and bomber-sized unmanned aircraft and the tests will continue through Fiscal 2012.

If future unmanned systems are able to refuel midair, those aircraft will add to the total of tankers needed.

Of the tanker sorties flown today, 83% support refueling operations only. About 2% of them are flown for “dual-use” missions, meaning the tanker provides aerial refueling and delivers cargo (both KC-135s and KC-10s can handle palletized cargo). Airlift-only missions account for about 3% and the remainder are “non-operational” sorties such as training, says Maj. Gen. Mark Solo, commander of the Tanker Airlift Control Center (TACC) here, which manages global airlift and refueling mission planning.

Of the missions in support of the wars in Iraq and Afghanistan from July 2008 to June 2009, 11% were refueling sorties, says Capt. Justin Brockhoff, a TACC representative.

On any given day, roughly 17 aircraft are on alert in the U.S. and Turkey supporting homeland defense units, and they can be called up to support fighters in an emergency, Solo adds. Some tankers still support the nuclear alert mission, though that posture has decreased since the end of the Cold War.

The KC-X will be required to have cargo doors, floors and defensive systems. The goal is to use the tankers for cargo carriage when they are not being flown in aerial refueling missions. During a wartime materiel movement, about 40% of the military’s cargo is shipped by the Civil Reserve Air Fleet, commercial providers that are tapped for military operations. These aircraft, however, lack defensive systems. “If they have to stop short—be that in Guam, Hawaii or Alaska or somewhere in Europe—and we have to carry that load somewhere forward in the battle zone, you have to transload it onto an airplane that is compatible with the CRAF, which the KC-X will be, and move that forward,” Merrill says. “We will always use tankers first to support their primary mission, which is aerial refueling [but] we know that during the course of the campaign there are times that some of those tanker will be available to do other missions.”

Senior Pentagon officials expected the KC-X draft request for proposals to be released during the summer, but recently said it would come out this fall. This will begin the next, long-anticipated duel between Boeing and Northrop Grumman/EADS to supply the Air Force with a KC-135 replacement.


KC135 Tanker Aw_09_10

https://i.servimg.com/u/f81/13/61/41/93/aw_09_10.jpg

Bonne lecture


_________________
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jullienaline
jullienaline
Whisky Charlie

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Message par jullienaline Ven 9 Oct 2009 - 17:42

Bonjour à tous,

Il est sur qu'au train où va le programme KC-X, il risque de rester sur le pont encore longtemps...
415 KC-135 devraient recevoir un nouveau tableau de bord dernier cri.

Rockwell Collins selected for KC-135 Block 45 cockpit upgrade program

The U.S. Air Force has selected Rockwell Collins for the Engineering, Manufacturing and Development (EMD) phase of the KC-135 Block 45 cockpit upgrade program. Under the contract, Rockwell Collins will modernize the KC-135 refueling tankers flight deck with the latest generation autopilot, flight director, radar altimeter and electronic engine instrument display. Two prototype aircraft will be modified during the EMD phase to establish the production baseline for 415 additional KC-135 aircraft expected to receive the Block 45 upgrade.

"The Block 45 upgrade continues Rockwell Collins' role in transforming the KC-135 by replacing obsolete components with the latest digital avionics technology for increased safety, efficiency and reliability," said Phil Jasper, vice president and general manager of Mobility and Rotary Wing Solutions for Rockwell Collins. "As the prime contractor for the KC-135 Global Air Traffic Management (GATM) program we've had a very successful history of delivering these upgrades on time and on budget, which played an important role in winning this latest contract."

Rockwell Collins is providing the technology that ensures the KC-135 meets current and future Communication/Navigation/Surveillance and Air Traffic Management (CNS/ATM) requirements, allowing it to operate in commercial airspace throughout the world. Rockwell Collins has modified and delivered more than 300 GATM equipped KC-135 aircraft to date.

The Block 45 upgrade builds on this success by providing increased safety with a state-of-the-art autopilot system. The autopilot flight director system and upgrades to the flight management software provide the user with vertical navigation capabilities, increasing the already robust KC-135 navigational capabilities. The contract also calls for replacing the aging analog engine instruments with a large format color electronic engine instrument display.

The KC-135 Stratotanker provides the core aerial refueling capability for the U.S. Air Force and has excelled in this role for more than 50 years. This unique asset enhances the Air Force's capability to accomplish its primary missions, while providing aerial refueling support to Air Force, Navy, Marine Corps and allied nation aircraft.
http://www.defpro.com/news/details/10412/

Amicalement


_________________
Jullienaline
Poncho (Admin)
Poncho (Admin)
Whisky Charlie

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Message par Poncho (Admin) Ven 26 Fév 2010 - 8:17

Bonjour à tous !

Des winglets sur les KC135r existant ?

http://www.flightglobal.com/blogs/the-dewline/2010/02/winglets-coming-for-kc-135rs.html



NASA used the Boeing KC-135 in the early 1980s to pioneer the design of the winglets that are now ubiquitous on commercial airliners and business jets.

Now, in a full-circle-Oprah moment, winglet technology may be coming back to the KC-135, only this time to benefit the refueling fleet itself.

Upon the request of the Air Force Research Laboratory and Air Mobility Command, the Air Force Academy published a study last month with new findings showing that adding winglets could reduce KC-135R fuel burn by 8%. They may have saved themselves some trouble by simply referring to NASA's original study, which predicted a 7% benefit.

The US Air Force spends $1 billion a year to pay for the gas consumed by KC-135s and KC-10s, according to this Rand web site. An 8% fuel savings extrapolates to $80 million a year. But the question remains how to pay for it. There is apparently some level of Congressional interest in the project, as Congress ordered the USAF to commission Rand's analysts to publish another study about KC-135R winglets.




La NASA a déjà testé par le passé des winglets sur les KC135 avec succès.
Gain de 7% sur la consommation et en tout cas 4.5% de réduction de la trainée.

Cela permettrait d'alléger la facture actuelle de carburant...

D'études en études à suivre

Bonne journée


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jullienaline
jullienaline
Whisky Charlie

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Message par jullienaline Mar 23 Mar 2010 - 23:52

Bonsoir à tous,

Un article interressant donnant une indiquation de l'horaire annuel d'utilisation des CFM-56 équipant les KC-135 de l'US Air Force : environ 500 h/an.
Le premier moteur livré totalise 13 409 h de vol en 26 ans de carrière. Il vient de subir un petit incident sur ses aubes de turbine.
Après réparation, il sera renvoyé au service actif.

U.S. Air Force maintainers remove 26-year-old KC-135R engine

The first KC-135R Stratotanker F108-100 engine delivered to the Air Force 26 years ago in the United States made its last flight March 1 here.

When KC1-35R tanker engines were originally purchased from CFM International, it marked the first time in history military officials bought a commercial engine for its aircraft. Upon purchase, the engine model, CFM56-2B, was designated as the F108 model by the Air Force.

Like the other F108 models, the engine from McConnell Air Force Base will be refurbished and returned to service.

Before being removed, the engine was used March 1 in two refueling missions. While preparing the aircraft for a third refueling mission, Airmen from the 22nd Aircraft Maintenance Squadron noticed the blades on the engine's turbo fan were unlatched at three positions around the rotor.

"With some difficulty, the blades were re-latched and an engine run was accomplished, after which the blades were observed to be un-latched again," said Brad Mehlinger, a CFM International field service engineer. "This is not considered abnormal on engines with high operating hours."

He said the maintainers attempted to latch the blades again, but weren't successful.

"After two hours we determined that the engine required removal," said Tech. Sgt. Jake Salinas, a 22nd AMXS engine mechanic.

During its 26-year career, the engine accumulated 13,409 hours of flight.

"This engine was hanging tough until this happened," Mr. Mehlinger said. "Even after more than 26 years in service, this engine was not due for scheduled maintenance for another two or three years."

The 8,000-pound engine was removed March 3, by four members of the 22nd AMXS. It took them 24 hours to remove the engine and wrap it before sending it to the 76th Propulsion Maintenance Group at Tinker AFB, Okla.

Members of the 76th PMG workforce will disassemble, inspect, repair, re-assemble and perform diagnostic testing on the engine and its parts before it takes flight again, a process that can last approximately six to eight months.

"This engine was the first to be delivered to the Air Force in the United States, and it's the last remaining original R model," said Capt. Jacob Sullivan, the officer in charge of the 22nd AMXS Green Aircraft Maintenance Unit. "It was impressive that it ran this long without repair, but everything wears out eventually."
http://www.defpro.com/news/details/13771/

Solide le CFM ! Pourtant, ce n'est pas un RR KC135 Tanker Icon_wink

Amicalement


_________________
Jullienaline
Poncho (Admin)
Poncho (Admin)
Whisky Charlie

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Message par Poncho (Admin) Mer 24 Mar 2010 - 9:10

Salut Jullienaline...

Il est certes vieux, mais avec seulement 15 000 h... il a peu consommé de potentiel...
Le record sans dépose pour un RR est il me semble à plus de 50 000 h sur un moyen courrier (757)...

M'enfin ... 8 mois pour la révision, elle doit être sacrément extensive... on est dans un autre monde où les moteurs civils doivent se sentir bien à l'aise avec ces cadences de vol restreintes...


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@avia.poncho
jullienaline
jullienaline
Whisky Charlie

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Message par jullienaline Mer 24 Mar 2010 - 23:24

Salut Poncho,

Bien sur son potentiel n'est pas beaucoup entamé.
C'était juste l'occasion de faire un amical clin d'oeil à un KC135 Tanker 735714 que nous avons connu dans une autre vie...

Cela conforte aussi mon interrogation sur le devenir de ces moteurs quand les KC-135 vont partir à la retraite. Pourquoi ne pas les avoir prévus sur les E-8 ?

Amicalement


_________________
Jullienaline
Jeannot
Jeannot
Whisky Quebec

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Message par Jeannot Mer 8 Avr 2015 - 0:37

Belle brochette !!!

KC135 Tanker A11
Poncho (Admin)
Poncho (Admin)
Whisky Charlie

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Message par Poncho (Admin) Mer 8 Avr 2015 - 9:43

Merci
C'est ça qu'on appelle éléphant walk ?
Je n'avais jamais fait attention à la forme des pylones... le moteur est porté bien haut !

Et tout ça à quel age ?


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massemini
massemini
Whisky Quebec

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Message par massemini Mer 8 Avr 2015 - 10:24

Les derniers (dont les nôtres), sont sortis en 1965, bien fumants, bruyants et gourmands pour la puissance qu' ils avaient à l' époque

Comme tous les avions récents ou plus anciens re-motorisés, le haut des nacelles est à hauteur du bord d' attaque de la voilure. Le KC 135 a été l'un des 1er cas avec les super DC8 et le 737.
massemini
massemini
Whisky Quebec

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Message par massemini Dim 12 Mar 2017 - 11:13

http://aviationweek.com/defense/short-cash-kc-46-us-air-force-eyes-souped-kc-135

Si cette modernisation (électronique de défense essentiellement), se réalise sur les 300 derniers produits au début des années 60, un siècle de service en perspective....
Poncho (Admin)
Poncho (Admin)
Whisky Charlie

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Message par Poncho (Admin) Dim 12 Mar 2017 - 22:21

Ben les CFM56 des dernières versions ne sont pas si vieille que ça vs les PW4000
Et puis ça vole peu cette machine


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massemini
massemini
Whisky Quebec

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Message par massemini Lun 13 Mar 2017 - 9:20

Environ 700 H par an (temps de paix). Soit 70000 à peine en un  siècle.
Il y a quelques années j' avais lu qu' un CFM56 avait cumulé quelque 40000 H sous voilure, sans dépose...
Poncho (Admin)
Poncho (Admin)
Whisky Charlie

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Message par Poncho (Admin) Lun 13 Mar 2017 - 9:44

Oui c'est ça 40000 h...
Ce qui compte de sont les cycles... 70 000h ça fait 35000 cycles max
Pour référence un A320 c'est 60000 FC et 120000 FH (http://www.airbus.com/presscentre/pressreleases/press-release-detail/detail/new-service-package-will-extend-a320039s-life/) et même plus je crois maintenant


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Laurent Simon
Laurent Simon
Whisky Quebec

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Message par Laurent Simon Mar 14 Mar 2017 - 16:21

Je viens de lire l'article cité, ainsi que les nombreux posts du forum associé.
Je suis assez surpris de constater à quel point tout et son contraire est dit, sur ce que peuvent durer ces 'vénérables' -135.
J'avais lu une étude, très détaillée, il y a quelques années, sur le vieillissement de ces avions, qui concluait sur la non pertinence de raisonner en coût de l'heure de vol. Puisque le vieillissement n'était pas lié aux heures de vol, mais à l'âge de ces avions notamment.

Finalement, les meilleures lectures dans ce domaine, comme dans celui de la défense en général, semblent être les écrits de la Cour des Comptes américaines (GAO), mais je n'ai rien lu de leur part depuis qq temps, faute de temps. J'imagine qu'ils ont fait un écrit tous les 1 ou 2 ans sur le sujet des ravitailleurs, mais n'ai pas le temps de regarder, dommage.

Cette GAO pourrait également éclairer d'un excellent angle la question de la distinction entre investissement et coûts de maintenance, qui fait qu'on ne peut souvent réduire la maintenance en achetant mieux... ... question qui était malheureusement classique en France (qui a permis de nombreux gâchis), et les youess semblent pris dans les mêmes contradictions.
Alors que les réformes récentes en France (budgets pluriannuels, sous un nom savant que j'ai oublié) a amélioré les choses il me semble, ces dernières années.
Philidor
Philidor
Whisky Quebec

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Message par Philidor Mar 14 Mar 2017 - 18:13

Faisons confiance à Boeing pour tuer sans tarder cette idée malencontreuse, au besoin par un lobbying approprié.

Ne faisons pas à l'USAF l'injure d'imaginer qu'elle puisse ne pas savoir que ce 'projet' n'a aucune chance d'aller au bout. Tirons-en la conséquence que celui-ci n'est qu'une ficelle comme une autre pour obtenir un complément de financement des nouveaux ravitailleurs, conclusion qui réjouira à la fois Boeing et l'USAF.
Paul
Paul
Whisky Quebec

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Message par Paul Mar 14 Mar 2017 - 23:36

Laurent Simon a écrit:
J'avais lu une étude, très détaillée, il y a quelques années, sur le vieillissement de ces avions, qui concluait sur la non pertinence de raisonner en coût de l'heure de vol. Puisque le vieillissement n'était pas lié aux heures de vol, mais à l'âge de ces avions notamment.

Et bien le KC-135 est l'exemple parfait du contraire, certains voleront près de 100 ans justement parce qu'ils volent peu.
Laurent Simon
Laurent Simon
Whisky Quebec

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Message par Laurent Simon Mer 15 Mar 2017 - 12:13

Paul a écrit:
Laurent Simon a écrit:
J'avais lu une étude, très détaillée, il y a quelques années, sur le vieillissement de ces avions, qui concluait sur la non pertinence de raisonner en coût de l'heure de vol. Puisque le vieillissement n'était pas lié aux heures de vol, mais à l'âge de ces avions notamment.

Et bien le KC-135 est l'exemple parfait du contraire, certains voleront près de 100 ans justement parce qu'ils volent peu.
L'étude, très approfondie, était exactement sur ces avions, et aucun autre.
Je ne l'ai malheureusement pas sous la main.
Parmi les conclusions : celle qui consiste à dire que ce ne sont pas les heures de vol qui sont un critère pertinent !
Beochien
Beochien
Whisky Charlie

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Message par Beochien Mer 15 Mar 2017 - 12:42

Beaucoup de choses peuvent vieillir sans voler !
Tous les câblages, la connectique, les bobinages des solénoïdes, les joints de l'hydro, l'oxydation des alliages avec conséquence les pertes de caractéristiques d'origine, des jeux ... et je dois en oublier ...
Laurent Simon
Laurent Simon
Whisky Quebec

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Message par Laurent Simon Mer 15 Mar 2017 - 21:41

Cet article, que je n'avais pas vu passer, il y a 6 mois :
http://airforcemag.com/DRArchive/Pages/2016/September%202016/September%2021%202016/On-to-the-Stealthy-KC-Z.aspx

L'étape KC-Y serait remplacée par l'achat de KC-46 supplémentaires et d'upgrades, et la suivante KC-Z ne serait pas nécessairement pour des avions de plus grande taille, mais pourrait être plus petit, un drône ?, et furtif (ce qui fait un lien avec les articles signalés ici sur la possibilité de furtivité ; j'avais rappelé le projet HWB de Lockheed)

"The KC-Z might not be a large-size tanker, he said: it might be a smallish unmanned autonomous vehicle that could penetrate an anti-access, area-denial system along with F-35s and other stealth combat aircraft. Studies are underway now, Everhart said, and he is meeting with industry at the AFA conference to explore the realm of the possible. “We are engaging with industry to find out from them … What are you thinking about?” for a next-gen tanker, Everhart explained. Everything will depend on available money, but Everhart said he’s looking at blended/hybrid wing designs already appearing as industry concepts."

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