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.