* Move paves the way for training, test flights
* Fleet of 25 F-35B jets grounded after fuel line detached
* Pentagon says hoses with problems to be replaced
By Andrea Shalal-Esa
WASHINGTON, Feb 13 The Pentagon and U.S. Navy
have lifted flight restrictions on the Marine Corps version of
the F-35 fighter jet, clearing the way for testing and training
flights to resume after a nearly month-long grounding, military
officials said on Wednesday.
The decision would allow officials to quickly resume flight
tests of the F-35B, the Marines' version of the new warplane
being built by Lockheed Martin Corp, said Colonel Kevin
Killea, who oversees aviation requirements for the Marine Corps.
He said, however, that the Navy and the F-35 program office
had more work to do to resolve the manufacturing issues blamed
for the grounding.
Resumption of test and training flights of the F-35B is good
news for the $396 billion F-35 program, which must complete an
aggressive schedule of test flights this year to keep the
program on track after earlier delays.
The Pentagon and the Navy grounded all 25 F-35B jets on Jan.
18 after a fuel line made by Stratoflex, a unit of Parker
Hannifin Corp, detached just before a training flight in
Florida on Jan. 16. The Pentagon later said the issue stemmed
from a manufacturing defect, not maintenance or design issues.
Joe DellaVedova, spokesman for the Pentagon's F-35 program
office, said all 25 F-35 B-model warplanes were cleared for
flight as soon as any defective fuel lines had been replaced.
He said all the affected hoses had been inspected and those
found to have problems would be replaced. The hose in question
is part of the exhaust system on the F-35B, which can take off
from short runways and land like a helicopter.
Stratoflex is a subcontractor to Britain's Rolls Royce Plc
, but the prime contractor for the F-35B engine is Pratt &
Whitney, a unit of United Technologies Corp.
The Pentagon's F-35 program office lifted the flight
restrictions on nine developmental test F-35B aircraft, and Vice
Admiral David Dunaway, head of Naval Air Systems Command,
followed suit later by approving flights by 16 additional F-35B
jets that are being used for training, defense officials said.
Flights of the Air Force's A-model and the Navy's C-model of
the F-35 were unaffected because they do not have the same fuel
line involved in the incident that triggered the grounding.
Lockheed is building three variants of the F-35 for the
United States and eight countries that funded its development:
Britain, Canada, Australia, Norway, Denmark, Italy, Turkey and
the Netherlands. Israel and Japan are also buying the planes.
Besides the Marine Corps, Britain and Italy also plan to buy
All the aircraft will have to undergo an initial checkout
flight before they can resume testing or training flights, said
a defense official who was not authorized to speak publicly.
The official said it was unclear how the grounding would
impact the overall test program for the F-35B since that model
had been a bit ahead of schedule with flights before the
grounding. "There will be some impact for sure. Thirty days of
testing is 30 days," said the official.
The Pentagon continues to analyze equipment made by
Stratoflex and remains in discussions with Pratt about the cost
of the detailed inspections and repairs, the official said.
Matthew Bates, a spokesman for Pratt, welcomed the decision
to resume flights of the F-35B and said the root cause had been
corrected. "We took additional steps with our supplier to ensure
hose integrity for the entire fleet, and we are confident in the
integrity of the overall propulsion system," he said.
Bates had no immediate comment on who would pay for the cost
of the inspections and repairs resulting from the incident.
So far, 82 hoses from the F-35B aircraft have been shipped
to an independent company in Minnesota for CT scans. Initial
analysis showed 10 of 36 hoses were overcrimped and needed
repairs, said the official, adding that five sets of hoses had
been cleared for use.
Pentagon and Navy officials have adjusted the requirements
for the hoses after studying the performance of a test engine,
being used by Pratt & Whitney, that was found to have an
overcrimped hose but logged 1,600 hours of use without a