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Air Force Grounds ‘Combat Ready’ F-35 Over Coolant Line Flaw
by Anthony Capaccio
September 16, 2016 — 8:45 PM IDT
Updated on September 17, 2016 — 12:18 AM IDT
http://www.bloomberg.com/politics/articles/2016-09-16/air-force-grounds-combat-ready-f-35s-over-coolant-line-flaws

Seven weeks after the Air Force declared its first F-35 jets combat ready,
10 of the aircraft aren’t flying after service mechanics discovered “peeling
and crumbling” insulation wrapped around lines that carry liquid to cool
combat systems and computers.

The poor insulation is suspected on 57 aircraft, including 42 on Lockheed
Martin Corp.’s production line. The issue is not a design flaw with the
aircraft but instead caused by manufacturing quality glitches with one of
two subcontractors which make the 18 lines through which the coolant flows,
according to an Air Force statement and an interview with a service
official, who asked not to be identified.

If not fixed, the crumbling insulation could become lodged in the lines
connecting the aircraft’s wing and fuselage fuel tanks causing potential
overpressure or underpressure that “may cause structural damage to the fuel
tanks,” according to a statement sent Friday to House and Senate defense
committees.

“The issue was discovered during depot modification” of an Air Force jet and
has resulted this month in a “temporary pause in flight operations,”
according to a separate statement from the service. Ten of the 15 aircraft
not flying are located at Hill Air Force Base, Utah, home of the service’s
first combat-ready squadron. The other five aircraft don’t have the flawed
insulation and continue to fly regular sorties, the office said. Two
aircraft delivered for Norway are also not flying, said the official.
Another three F-35s have been grounded at other bases, for 15 total.

‘Corrective Actions’

Twenty of the aircraft that need to be fixed on the production line belong
to foreign countries, according to Air Force data: Eight to Israel, six to
Japan, and three each to Italy and Norway.

Lockheed Martin spokesman Michael Rein said in a statement that “safety is
always our first consideration and Lockheed Martin is committed to resolving
this issue as quickly as possible to return jets to flying status.” The
issue “is confined to one supplier source and one batch of parts,” he said.
Rein declined to identify the subcontractor involved.

‘Proven Track Record’

F-35 spokesman Joe DellaVedova said in an e-mail that the Pentagon program
office and Lockheed Martin “have a proven track record of solving issues and
we’re confident we’ll continue to do so. The government and industry team is
now developing repair procedures to remedy the problem and return the
affected aircraft back to safe flying operations.”

The Marines Corps and Navy versions are not affected by the problem, which
has been traced to the “use of nonconforming material for the tubing
insulation and improper manufacturing processes during fabrication of the
cooling lines,” DellaVedova said. “The nonconforming material that was used
is not compatible with fuel, causing degradation of the insulation and
resulting in it falling off the tubing.”

A spokesman for the Pentagon’s director of combat testing said the office
was made aware this week of the problem. The issue does not appear at this
time to be affecting test aircraft the service has designated for the
intense combat evaluation the program is planned to undergo in 2018, he
said.

As to the 42 aircraft on Lockheed Martin’s production line, “the extent and
nature of the repairs needed are not known at this point,” spokesman Army
Major Roger Cabiness said in an e-mail statement. “However, it is not
unreasonable to assume the repairs will require
opening the fuselage and/or wings to access the fuel tanks to replace
components or make repairs, which would be very intrusive and could require
extensive downtime.”

The Air Force has taken delivery of 104 F-35A models but the Pentagon’s
Defense Contract Management Agency has suspended delivery of additional
aircraft “until corrective actions” are in place, according to the Air Force
statement.

“Lockheed Martin has begun developing the repair process for these
aircraft,” the Air Force statement said.

The unnamed service official, who follows the F-35 program closely, said the
Air Force, Lockheed Martin and the Pentagon program office know precisely
which planes have the suspect insulation, so the overall program impact is
not widespread.

Still, it’s unknown at this point how long the aircraft will be grounded and
when the 42 aircraft currently on Lockheed Martin’s production line will be
modified with new insulation, the official said. Air Force and Lockheed
engineers should finalize a formal recovery plan by next week, the official
said.