As wave after wave of combat aircraft roar off the decks of U.S.
carriers in the Arabian Sea to attack targets in Afghanistan, the
Navy and Marine Corps are wrestling with the increasing age of their
The average Navy airplane is now 18 years old, Defense Secretary
Donald Rumsfeld told a Senate budget hearing earlier this year.
Some are considerably older. The F-14 Tomcat first flew in 1970.
The S-3B Viking entered service in 1975.
“For the first time, our average aircraft age exceeds the
average age of our combatant ships,” said Adm. William J.
Fallon, vice chief of naval operations.
Most Marine helicopters are more than 25 years old, said the corps’
assistant commandant, Gen. Michael J. Williams. “Some of our
younger pilots are flying the exact same aircraft that their fathers
The reason for this increasing age, Rumsfeld explained, is that
the two services have not been able to buy enough new planes every
year. He cited this example: To maintain its required 4,200 aircraft
at an average age of 18 years, “the Navy needs 180 to 200
new aircraft per year at a cost of $11 billion.”
The 2001 budget amendment, however, would provide 97 aircraft at
a cost of $8.4 billion, Rumsfeld noted, and the 2002 budget would
add 88 airplanes at a cost of $8.3 billion.
As the average age of the Navy’s aviation force goes up,
“there has been a corresponding increase in the costs of operations
and maintenance,” Fallon said. “Specifically, the cost
of aviation depot-level repairables—which is driving the cost
of maintaining our aircraft—has risen an average of 13.8 percent
To help stem these costs—and to keep aircraft flying safely
as long as possible—the Naval Air Systems Command in 1999
established an Aging Aircraft Integrated Product Team. The team,
which is headquartered at the Patuxent River Naval Air Station,
Md., has been assigned to spearhead efforts to improve readiness
and reduce lifecycle costs for Navy and Marine Corps aircraft.
The team is pursuing a systems-engineering approach, said its leader,
Robert P. Ernst. “I don’t have a large staff,”
he told National Defense. The team consists of 16 fulltime personnel,
with others working part-time. It includes representatives from
the major aircraft programs operated by the two services.
The focus of the team is to find new and better ways to counter
the problems caused by age, Ernst explained. Chief among the targets
are faulty wiring, corrosion and fatigue, he said.
The Biggest, Ugliest Dogs
“We’re resource-limited,” he said. “So we’re
going after the biggest, ugliest dogs first.”
For example, the team has worked with the Office of Naval Research
and the Federal Aviation Administration to develop an arc fault
circuit breaker to protect military and civilian aircraft from problems
caused by aged electrical wiring.
Modern aircraft have thousands of feet of such wiring, explained
senior electrical engineer Charles H. Singer Jr. Over time, the
insulation protecting that wiring degrades, he said. “In a
building, insulation might last 100 years. In an airplane, it could
wear out in maybe 10 or 15 years.”
The wiring—and its insulation—can be damaged by extreme
weather, moisture, fuels and the stress associated with flight and
even routine maintenance, Singer said. About half of all Navy and
Marine aircraft are equipped with old forms of aromatic polyimide
insulation, which the Navy stopped installing in new combat aircraft
in 1986 because of its poor arc-tracking characteristics.
As this insulation ages, it is particularly susceptible to deterioration,
cracking and flaking, Singer explained. This, in turn, can lead
to arc faults and failure of the wire, creating a fire hazard.
“In one 30-month period, we documented 64 in-flight electrical
fires,” Singer said. The arc fault circuit breaker—which
is similar to those used in residential homes, but smaller and much
sturdier—is intended to help prevent such fires.
“The arc fault circuit breaker will detect a problem and
keep it from killing you,” said Singer.
Prototypes have been built by Eaton Aerospace, in Sarasota, Fla.,
and Hendry Telephone Co., of Santa Barbara, Calif. Flight tests
began this summer aboard a Boeing 727 airliner supplied by the FAA
and a Navy C-9 transport.
If all goes well, Singer said, a breaker will be available in the
fall of 2003 for use in the 727, C-9 and Navy E-6 airborne command
post. “Fighters and helicopters use a smaller breaker,”
he noted, and that should be available in 2006.
To speed up the process of finding and replacing aged wiring systems,
NavAir is partnering with ONR, Management Sciences Inc. and Utah
State University to develop “smart-wire” technology.
Smart wiring involves the embedding of intelligence and sensors
in wiring systems to monitor and manage the health of the systems,
explained the program’s head, Sean Field, an electrical engineer.
Most Navy and Marine aircraft would benefit from such technology,
which could be installed easily in existing aircraft, he said.
Up to 2 million man-hours per year are required at the organizational
level to troubleshoot and repair aircraft wiring-system problems,
Field said. Wiring troubleshooting and repair are still “hands-on”
activities, which have changed very little in the past 40 years,
“There is a pervasive need for an automated or semi-automated
system for managing the health of the wiring system,” Field
said. Wiring systems should be managed in the same manner as avionics
systems and engines.
The smart-wire system is intended to meet this need. It is meant
“to detect, isolate and locate wiring faults quickly and expedite
repairs on the flight line,” Field said. It also “should
capture and store, for future analysis, the in-situ condition of
an aircraft wiring system’s health on a tail-number basis.”
This, he said, would permit maintenance intervention before a wiring
A prototype smart-wire system is scheduled for completion in April
2002, Field said. The finished system is expected to be ready for
the fleet in 2006.
Another enemy of Navy and Marine aircraft is corrosion. About two
thirds of the strikes against targets in Afghanistan during the
opening weeks of that campaign were conducted by carrier-based aircraft.
Maintaining aircraft aboard a carrier—where waves of seawater
frequently wash over the deck and the very air is full of salt—is
a constant battle against corrosion, said Ernst.
“Aircraft corrosion was a $1.4 billion problem for the Navy
and Marine Corps last year,” he noted. “By far, it’s
our largest single cost driver.”
Corrosion in aircraft takes many forms, said Kevin Kovaleski, organic
coatings team leader. “There isn’t any one goose with
golden eggs that we can jump on,” he said. “It takes
a lot of dirty fingernail work, and that’s what we have been
The team has been working with NavAir’s Organic Coatings
Laboratory, also located at Patuxent River, to develop a new spot
corrosion kit to replace the older technology currently in use.
The kit contains everything a technician needs to treat corrosion,
The disks, built by the 3M Corporation, are made of plastic containing
aluminum oxide and a proprietary element that gives them a grit
of 400, said Kovaleski. The disks currently in use “are way
too abrasive,” he noted, requiring more stripping and repainting
than is necessary.
The new versions make it easier for maintainers to remove small
areas of corrosion “before it gets out of hand,” he
explained. The disks also enable maintainers to strip less metal
and reapply less paint, thus reducing maintenance costs.
The kits should be ready for distribution to the fleet beginning
in late 2002, Kovaleski said.
NavAir engineers developed another kit to speed up the spot-paint
repairs of aircraft, while reducing overall procurement and disposal
costs, according to Navy spokesman John Milliman.
The centerpiece of this kit is a pencil-shaped product called SemPen,
he said. Made by PRC-DeSoto, of Glendale, Calif., the SemPen is
designed to store, mix and apply small quantities of two-component
paints and primers. It is small enough to fit in a shirt pocket,
like a pen.
The SemPen enables maintainers to do small spot-paint repairs without
the need to isolate the aircraft to protect nearby personnel from
toxic fumes associated with large amounts of aerosols and spray
paint. This enables other maintenance to be conducted at the same
time as the spot painting, Milliman explained.
As aircraft grow older, it gets more and more difficult to keep
them airworthy, said Laurence W. Stoll, head of integrated logistics
and operations support.
“Eventually, you either have to buy new aircraft—and
we can’t afford to buy enough of them—or you have to
do extensive work on your existing fleet,” he said.
Structural fatigue is an increasing worry, said Paul C. Hoffman,
head of the structures science and technology team. Military aircraft
are required to withstand randomly occurring fatigue during their
design service lives, he explained. Before the end of the Cold War,
aircraft usually were replaced at the end of those service lives.
Now, however, they are being kept in the fleet for much longer periods,
and maintainers are seeing more fatigue problems—including
visible cracks—than ever before, Hoffman said.
Because of relatively cramped quarters, carrier operations prohibit
extensive inspections and repairs aboard ship, so when problems
are detected the aircraft must be sent ashore for repairs, Hoffman
For the older platforms, it gets progressively difficult to find
spare parts or even repair manuals, Stoll pointed out. Production
lines shut down. Companies go out of business or merge with other
Ernst called it “defense Darwinism,” an economic “survival
of the fittest.” Some companies, he said, become larger and
stronger, while others are consumed by the survivors, and still
others become extinct.
“We usually get about six weeks’ notice that somebody’s
no longer going to supply parts.,” he said.
Avionics—aircraft electronic systems—have been hit
particularly hard by this trend, Ernst said. He gave this analogy:
“You probably replace your computer every two or three years.
Our budgets cannot keep up with that kind of turn around.”
Avionics equipment is vastly more expensive than a personal computer.
Thus, he said, the avionics in older Navy and Marine aircraft is
often old and under powered. And keeping it running is difficult.
“Have you tried,” Ernst asked, “to buy parts for
a 286-chip computer lately? You don’t go out and buy this
stuff at Radio Shack.”
The Navy is doing a better job of taking care of its aging aircraft,
Ernst said, but it needs to do more. “If we put the tools
out there, we can assess the life cycles of our aircraft and make
good decisions about when to replace them,” he said. “We’re
not there yet.”
The Navy aging aircraft program needs to line up additional funding
for testing, engineering, acquisition and logistical support, Ernst
said. “It takes an enormous amount of work.” He noted
that he made 60 major presentations last year himself.
“It would be nice if we had a big pot of money out there
that we could tap into, but we’re doing guerrilla warfare,”
“We need to ratchet this team up a level,” he added.
The Air Force has a similar program, he pointed out, and it is headed
by a flag officer. “We need an equivalent.”
Ernst is a civilian employee of the Navy, but he joked: “I
have to earn my wings every day.”