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The F-15s continue to grow years older even as I type. If the F-15 squadrons at Langely are flying 30 year old aircraft Id be much surprised seeing as how they are flying F-15C aircraft not even in squadron service until 1979. But other than that nitpick Ill agree with the basic premise of the article. But the USAF has always lead the military in PR much to the chagrin of the USN. But if you see the article posted on the USN board by BigVette youll see they are learning.

Getting Worse With Age
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Air Force Times
August 2, 2004
Pg. 14

Getting Worse With Age

The Air Force searches for a permanent Band-Aid to counter the stress on its crumbling aircraft

By Laura M. Colarusso, Times staff writer

LANGLEY AIR FORCE BASE, Va. — When asked what effect age has on aircraft, Staff Sgt. William Pyle pushed his wire-rimmed glasses up the bridge of his nose, shook his head and chuckled.

“Where do you want me to begin?” he asked.

Pyle is an F-15 Eagle maintainer who, for the past eight years, has worked to keep Langley’s fighters airworthy. He helps inspect the aircraft after every 200 hours of flight — and that job is getting more difficult every year, Pyle said.

As the aircraft get older, more in-depth inspections are required. More panels have to be pulled off the airplanes to check for internal cracks and corrosion that might have cropped up. It’s the law of numbers, Pyle said. The more problems you look for, the more you will find.

Pyle is not alone in his fight. Practically every maintainer of every airframe is facing similar troubles. The Air Force’s aircraft are aging at a rapid rate. Fighters are an average of 19 years old, the average bomber is about 22 years old and the KC-135 tanker fleet is pushing 50 years, according to data provided by the service.

Air Force leaders say they are taking steps to fix the aging aircraft dilemma, but a high operational tempo and shrinking budgets are hampering progress.

For Pyle and his peers, the outlook is grim.

“More is breaking,” Pyle said, noting the trend will likely continue.

More time in the shop

Some things get sweeter with age. Aircraft don’t.

And from the F-15 fighters to the C-5 transports to the MH-53 Pave Low helicopters, the service is operating a rapidly aging fleet.

The average age of the operation force is “something like 22.7 years,” according to Air Force Secretary James Roche. The problems that come with age are starting to show throughout the service, he said.

If the Air Force respects its elders, then the KC-135 Stratotanker is arguably the most respected aircraft in the fleet. It entered the inventory in 1956, but the average KC-135 is 42 years old.

“Close to half of the KC-135Es that are flying today were flying when I was commissioned ensign,” said Roche, who entered the Navy in 1960, according to his biography.

Out on the flight line, maintainers are finding leaks in the fuel bladders. Corrosion on the engine struts is causing depot workers to spend thousands of man-hours grinding out the decaying metal.

The KC-135E’s depot work package has doubled in the past 13 years, an Air Force spokesman said. In 1991, it took 17,000 man-hours to get just one aircraft through depot. In 2003, that number jumped to 35,000.

Maintainers can expect the numbers to get worse. Richard Aboulafia, vice president of analysis for the Teal Group Corp., a Washington D.C.-based think tank, said that’s one thing almost everyone can agree on.

“Per flight hour, certainly, as the fleet ages, you will have to spend more both in terms of money and man-hours,” Aboulafia said.

The situation will only get worse unless the Air Force retires large numbers of its aging weapon systems, he added.

Even when problems are located, fixing them is not always easy. The aircraft are so old that it’s difficult to get some spare parts because the original manufacturers are no longer making them or have closed down altogether.

So jets that are already down for maintenance become donors, giving their parts to other aircraft that are in need. The process is called cannibalization.

And with increasing frequency and innovation, maintainers also have started to make parts from scratch.

Past their expiration dates

Despite the relentless efforts of maintainers and depots, planes are starting to show their age.

Since 1991, the KC-135 fleet’s mission-capable rate — the percentage of aircraft that are available for their mission at any given time — has declined. In fiscal 1991, the KC-135 fleet had a mission-capable rate of 82.4 percent. Thirteen years later, the rate has dropped to 77.3 percent.

The F-15s have experienced a similar decline, going from 81.2 percent in 1991 to 74.6 percent in 2004.

As the F-15s get older, the maintainers have to conduct more intensive inspections, or “phase dock” in maintenance jargon. The number of “work cards” or checklists of tasks that must be accomplished has more than doubled in Pyle’s eight years here.

The average F-15 is 17.8 years old, according to data provided by the Air Force. But Pyle and his colleagues at Langley have to deal with jets that are almost 30.

It’s not just the number of years that causes problems. It’s the number of flight hours and the type of flying being done in the F-15 that are degrading the aircraft’s structural integrity.

“It’s just like when you take your car in for service,” Pyle said. “Look at your driver’s manual and see what’s required for a 30,000-mile inspection versus the 100,000-mile inspection.”

More panels have to get opened up, which means they have a greater chance of finding more problems such as corrosion and wire chafing.

And cracks.

Because the F-15 flies in a high-stress environment and has to sustain multiple G maneuvers, the airplanes are cracking.

“We know that when these aircraft come in, they’re going to be cracked, stressed, fatigued [and] leaking,” Pyle said.

To prove his point, Pyle knocked on the side of an engine inlet, one of the most hollow parts of the aircraft.

“Do you hear that twang?” he asked. “There’s a crack there.”

In the July heat, with temperatures climbing to 100 degrees and sweat beading off his brow, Pyle crouched under the belly of an F-15 to point out more cracks. The vertical tails are also vulnerable to cracking, he said.

“Instead of finding one or two cracks, we’re finding 10,” Pyle said, comparing the numbers from when he began working on the jet to today. “Cracks on the intake are an everyday thing.”

To fix the cracks, sheet metal experts have to cut holes in the plane to see what’s going on behind the outer skin. Once the metal is removed, maintainers can find a variety of problems. Around the wings where the fuel is stored, corrosion and leaking often occur.

“The older these jets get, the more work we have,” said Staff Sgt. Derek Aubuchon, a sheet metal expert at Langley. “They’re not like wine. They don’t age well.”

Over time, the metal becomes more brittle and worse at handling the G forces that push against the plane during high-stress maneuvers, Aubuchon said. The phenomenon is called fatiguing.

“The jets can take less and less over time,” he said.

To repair a crack, Aubuchon -creates a metal patch to cover the hole he makes to inspect behind the crack. The metal he uses is thicker than the rest of the aircraft skin, which puts more stress on the surrounding structure.

It’s not uncommon to see a row of patches — some of which are 30 square inches or bigger — down the side of an engine inlet, Aubuchon said.

And this problem will only worsen with time.

“My personal opinion is that these jets weren’t supposed to fly this long,” Aubuchon said. “They’ve passed their expiration dates.”

Officials from the Aging Aircraft System Program Office at Wright-Patterson Air Force Base, Ohio, seconded Aubuchon’s opinion and said fighters are being flown well past the age when they were initially intended to be retired.

As a result, issues that engineers and maintainers never would have expected are now cropping up on a daily basis.

The F-16 Fighting Falcon, for example, is seeing more frequent cracks on the landing gear and throughout the fuselage.

F-16 maintainers at Luke Air Force Base, Ariz., are discovering chafed wiring — something they never anticipated and have no set protocol to fix.

These problems are “due to the operation of many aircraft in excess of their original projected service life,” Air Force officials wrote in response to questions.

And the F-16s are not alone.

The A-10 attack jet has encountered delamination and cracks in the flight control surfaces and corrosion around the fuel cell floor. The C-141 airlifter has fuel system leaks. The C-130 Hercules has “increasing ‘aging aircraft’ issues such as corrosion [and] cracking,” officials also wrote.

Cutting aircraft to cut costs

Isolating the cost associated with aging aircraft is difficult. But no one denies the basics of aircraft math: The older an aircraft is, the more expensive it is to maintain.

“In certain of our aircraft, the cost to maintain is going up by 10 percent a year. And that includes inflation, so that’s 7 percent real,” Roche said, referring to cost per flying hour for the C-5 fleet.

The F-15C, the air-to-air variant of the fighter jet, has seen its operating costs jump by 20 percent a year since 2000, said Lt. Col. Will Nichols, a spokesman for Roche, in response to questions.

But the increase in flying hour costs is not an exact measure of how age affects maintenance rates. The cost per flying hour also includes the cost of fuel, which fluctuates from year to year.

Another measure of cost is the depot sales rate, which includes the amount of money spent on maintenance and upgrades done at one of the Air Force’s three logistic centers. The KC-135 fleet is incurring depot costs that are rising by at least 16 percent each year over the last four years, Nichols said. It costs approximately $3 million per jet to deal with corrosion on the engine struts of KC-135Es, according to Air Force documents.

One of the methods the Air Force is using to keep costs down is retiring older aircraft.

“You can keep old planes going, but they tend to cost more in maintenance like keeping an old car going,” Roche said.

Service officials have made plans to retire 68 of its oldest KC-135s because the cost to maintain them is becoming too great. At the same time, the aircraft are spending more time down for maintenance.

“It turns out they spend so much time at depot and so little time working that you really lose about 4 percent of your effective refueling capability by retiring 68 of them because they are not useful,” Roche said.

Plans are in the works to retire about half the F-16 fleet and a few older F-15s, a move that would save the Air Force millions of dollars in maintenance costs.

The B-1 community also has seen retirements. Defense advisers in the spring of 2001 recommended that Defense Secretary Donald Rumsfeld cancel the B-1 bomber’s $2 billion modernization plan, which is scheduled to run through 2007. They argued that the supersonic bomber was too unreliable and too expensive to maintain. Senior defense officials said the secretary was expected to recommend that the B-1 be retired and replaced by more stealth B-2 Spirit bombers.

The B-1 Lancer evaded this fatal strike, however, thanks largely to a rather radical maneuver.

Roche and Air Force Chief of Staff Gen. John Jumper in August 2001 eliminated one-third of the B-1 fleet. The politically unpopular move had three immediate effects:

** It reduced cannibalization rates. The B-1, or “Bone” as it is affectionately known, had a dismal 85.4 percent cannibalization rate in 2001, a year in which the Air Force average was 11.1 percent. By early 2003, however, the Lancer’s cannibalization rate had dropped below 50 percent.

** It helped improve mission capability. Rates that had hovered in the 50s held steady at 79 percent for Operation Iraqi Freedom.

** It saved the Air Force $130 million in the first fiscal year alone, which was invested back into the 60 remaining Lancers.

More recently, the C-5A underwent a fleet viability board inspection to determine whether it would make sense to retire the airlifters, which are 33 years old on average, because it is becoming too expensive to maintain them. The board recommended that 10 of the 70 be retired.

With $3 billion of investments in the engines and avionics upgrades, those 60 airworthy C-5s can last another 25 years, the board said.

Retiring aircraft is only half of the equation for fixing aging aircraft. The Air Force also has extensive plans to modernize its fleets, Roche said.

“It’s in the fighter attack area we saw a major problem, and the solution is that you get the F/A-22 and then the [Joint Strike Fighter],” the secretary said. “If [JSF] doesn’t come, it turns out that the F-16 has a series of new models for international sales and you could always pick up some of those.”

The Air Force would also like to lease 767 tankers from Boeing to replace the aging KC-135 fleet, Roche said.

An uphill battle

Maintaining a 20-year-old car can be tough. Putting 50,000 miles on that car each year makes it even tougher.

That’s the scenario many aircraft maintainers face as a result of the increased operational tempo since the Sept. 11, 2001, terrorist attacks.

Air Force jets have flown record-long sorties in Afghanistan and Iraq and constant combat air patrols over the United States.

Many units in the war on terror saw their mission-capable rates shoot up. This was due largely to spare parts availability, long hours by maintainers and the fact that some systems simply function better the more they’re used.

But this pace also has forced aircraft into phase dock more frequently and given maintainers more panels to pull off, more cracks to patch and more corrosion to grind off.

The MH-53 Pave Low helicopter has felt this bite.

Before Sept. 11, it would take 40 man-hours to keep the Pave Lows in the air for one hour. By December 2003, that number doubled.

“Deployed operations in austere locations have kept the aircraft maintenance and logistics support functions fully challenged and engaged,” Air Force officials wrote to explain the jump.

Maintainers are bearing the brunt of this ever-increasing workload — and it’s a responsibility Pyle and his troops take seriously.

“It’s on me to make sure the planes are safe,” Pyle said.

To meet deadlines, they work at least 10-hour days. It’s not uncommon for a maintainer in the Langley phase dock to pull a 14-hour shift. Working on weekends is common.

The hangar where they work is having an aging problem of its own, with parts of the ceiling falling out and the walls cracking.

Despite these challenges, the maintainers finish the phase inspections on time. Their workload has approximately doubled, but they can still turn the jets around within the five-, seven- and 10-day mandatory periods.

“We’re constantly running,”