Washington: The US Air Force has had to
ground dozens of F-22 fighter jets for the second time this
year after concerns a pilot suffered a lack of oxygen in the
cockpit, officers have said.
Commanders at a base in Virginia and in Alaska ordered a
"pause" in flights for the world's most expensive and advanced
fighter aircraft as a safety precaution, an Air Force
spokesman said.
The decision came after an incident last week in which a
pilot at Joint Base Langley-Eustis in Virginia suffered
"hypoxia-like" symptoms in mid-flight, Lieutenant-Colonel
Richard Johnson told AFP.
The announcement came only a month after the Air Force
grounded the entire Raptor fleet from May through
mid-September -- an extraordinary step -- to allow engineers
to check for possible problems with the plane's oxygen supply.
Analysts say the precise source of the problem remains a
mystery despite elaborate tests and safety measures.
The fleet was cleared to return to the air last month
without a clear explanation behind a spate of incidents in
which pilots appeared to suffer from a lack of oxygen.
"Part of our protocol is to allow units to pause
operations whenever they need to analyze information collected
from flight operations to ensure safety. That is what is
happening at Langley at the moment, and we support that
decision," Johnson said in an emailed statement.
About 30 F-22 Raptors are based at the Langley base in
Virginia, which President Barack Obama visited last week.
At Joint Base Elmendorf-Richardson in Alaska, senior
officers lifted the temporary flight ban yesterday after
having ordered the planes grounded last Thursday, he said.
The Air Force has been reluctant to discuss the problem
in any detail, particularly the circumstances of about a dozen
incidents affecting F-22 pilots over a three-year period.
At a cost of nearly USD 150 million for each plane, the
F-22 Raptor is designed mainly for dogfights against rival
fighter jets and the radar-evading aircraft were not used in
the NATO-led air campaign over Libya.
The Air Force has more than 160 F-22 Raptors in its fleet
and plans to build a total of 187.
Some US lawmakers and defense contractors lobbied for
years to fund a larger F-22 fleet but former defense secretary
Robert Gates succeeded in defeating their effort, saying there
was no urgent need to build more of the sophisticated
aircraft.
PTI
First Published: Tuesday, October 25, 2011, 12:55