Pentagon Lifts F-35 Grounding Following
March 1, 2013 - The Defense Department lifted
grounding of the F-35 Lightning II joint
strike fighter after analysis concluded that a
cracked turbine blade in an engine on a single
plane resulted from overuse in test operations,
according to an official with the F-35 Joint
In an email statement, the official, Kyra Hawn,
said engineers have so far discovered no other
cracks in inspections of the other engines, and
no engine redesign was needed.
"This decision concludes a cautionary flight
suspension that began on Feb. 21 after a
0.6-inch crack was found on a third stage
turbine blade of a test aircraft at the Edwards
Air Force Base, (Calif.,) F-35 Integrated Test
Facility during a routine inspection," Hawn
The blade also underwent comprehensive tests at
the Pratt and Whitney facility in Middletown,
Conn., she added.
The engine in question, she explained, is part
of the F-35 test aircraft fleet and had been
operated for extended time in the
high-temperature environment in its mission to
expand the F-35 flight envelope.
"Prolonged exposure to high levels of heat and
other operational stressors on this specific
engine were determined to be the cause of the
crack," Hawn said.
Within the current DOD inventory, 17 F-35s are
employed in test and development at Patuxent
River Naval Air Station, Md., and Edwards Air
Force Base. The remaining aircraft are assigned
to Eglin Air Force Base, Fla, and Marine Corps
Air Station Yuma, Ariz., and comprise the
initial F-35 training fleet.