By Associated Press – Thu, Sep 27, 2012 |
KADENA AIR BASE, Japan
(AP) - Years before F-22 pilots began getting dizzy in the cockpit,
before one struggled to breathe as he tried to pull out of a fatal
crash, before two more went on television to say the plane was so unsafe
they refused to fly it, a small circle of U.S. Air Force experts knew
something was wrong with the prized stealth fighter jet. Coughing
among pilots and fears that contaminants were leaking into their
breathing apparatus led the experts to suspect flaws in the
oxygen-supply system of the F-22 Raptor, especially in the extreme
high-altitude conditions in which the $190 million aircraft is without
equal. They formed a working group a decade ago to examine the problem,
creating an informal but unique brain trust. Internal
documents and emails obtained by The Associated Press show they
proposed a range of solutions by 2005, including adjustments to the flow
of oxygen into pilot's masks. But that key recommendation was rejected
by military officials reluctant to add costs to a program that was
already well over budget.
"This initiative has not been funded," read the minutes of their final meeting in 2007. Minutes of the working group's meetings, PowerPoint presentations and emails among its members reveal a missed opportunity for the Air Force to improve pilot safety in the 187-plane fleet before a series of high-profile problems damaged the image of an aircraft that was already being assailed in Congress as too costly. F-22 production was halted last spring and the aircraft has never been used in combat.
- In 2008, pilots began reporting a sharp increase in hypoxia-like
problems, forcing the Air Force to finally acknowledge concerns about
the F-22's oxygen supply system.
- Two years later, the oxygen system
contributed to a fatal crash. Though pilot error ultimately was deemed
to be the cause, the fleet was grounded for four months in 2011.
- New restrictions were imposed in May, after two F-22 pilots went on the
CBS program "60 Minutes" to express their continued misgivings.
The Air Force says the F-22 is safe to fly - a dozen of the jets began a six-month deployment to Japan in July - but flight restrictions that remain in place will keep it out of the high-altitude situations where pilots' breathing is under the most stress. One of the working group's proposed fixes, a backup oxygen system, is expected to be in place by the end of the year. And the Air Force, which blamed the oxygen shortage on a faulty valve in the pilots' vests, says a fix to that problem is also in the works. The working group also proposed changes in warning systems to alert pilots to system failures and urged enhanced tracking of potential health hazards to pilots and ground crew caused by the materials used to bolster the aircraft's stealth - two more issues the Air Force investigations would later focus on. More broadly, the Air Force now concedes that while its own experts were tackling the F-22's issues, it was too aggressive in cutting back on life-support programs intended to ensure pilots' safety. It is now in the process of rebuilding them.
According to the Air Force, RAW-G was created at the suggestion of Daniel Wyman, then a flight surgeon at Florida's Tyndall Air Force Base, where the first F-22 squadron was being deployed. Wyman is now a brigadier general and the Air Combat Command surgeon general. By
the time RAW-G got going, some pilots were already experiencing a
problem called "Raptor cough" - fits of chest pain and coughing dating
to 2000 that stem from the collapse of overworked air sacs in the lungs. The
group concluded that the F-22's On-Board Oxygen Generation System - or
OBOGS - was giving pilots too much oxygen, causing the coughing. The
more often and higher the pilots flew after being oxygen-saturated,
group members believed, the more vulnerable pilots affected by the
condition would be to other physiological incidents.
RAW-G
recommended more tests and that the F-22's oxygen delivery system be
adjusted through a digital controller and a software upgrade. "The
schedule would provide less oxygen at lower altitudes than the current
schedule, which has been known to cause problems with delayed ear blocks
and acceleration atelectasis," the technical term for the condition
that leads to the coughing, according to the minutes from RAW-G's final
meeting. RAW-G members had spent two years pushing for the change
in the oxygen schedule - the amount of oxygen pumped into pilots'
life-support systems - but the necessary software upgrade never came
through. "The cost was considered prohibitive in light of other items that people wanted funded for the F-22," said Kevin Divers, a former Air Force physiologist who spearheaded RAW-G until he left the service in 2007 and the group disbanded. Divers believes the cost would have been about $100,000 per aircraft.
The
link between oxygen saturation at lower altitudes and the recent spate
of hypoxia-like incidents at high altitudes remains a matter of debate,
and other contributing factors are likely. Both the Air Force and NASA,
however, now concur that the F-22's oxygen schedule needs to be revised. At
a House subcommittee hearing this month, Clinton Cragg, the chief
engineer for NASA's Engineering and Safety Center, said the current
schedules provide too much oxygen at lower altitudes - as RAW-G warned -
and also agreed with RAW-G that testing was insufficient "even back to
the beginning of the program." Lt. Col. Tadd Sholtis, a spokesman for the Air Combat Command
at Virginia's Langley-Eustis Air Force Base, the home base for the
F-22s deployed in Japan, said the RAW-G group was not meant to last
indefinitely. He said it was set up to help officials at Tyndall get up
to speed on the medical aspects of flying the F-22, and disbanded "after
several meetings and a safe transition to regular F-22 operations at
Tyndall." But even in the last days of the group, its members were
identifying more work that needed to be done. In an email to Divers
before RAW-G's final meeting, Wyman said health hazards for F-22 pilots
and ground crew needed more study.
"I
am interested in the potential physiologic/health issues related to
flying and fixing the F-22s," he wrote. He added that increased
gravitational forces during accelerated turns, high speeds and high
altitudes, noise and the "low observable" materials used to give the
aircraft its stealth qualities "might lead to new health issues." By
then, the F-22 was just one of the aircraft that concerned RAW-G.
Minutes from the final meeting include "action items" identifying
potential issues with the F-35 and the CV-22 Osprey, and a suggestion
that RAW-G's work continue with higher-level oversight so that it would
have more clout. But after Divers left the service, no one took up the
torch. The Air Force says it believes improvements now being put
into place make the planes safe to fly under limited restrictions. It is
now refitting all pilot life support gear, redesigning the vests so
that modified versions can be introduced in the fall, and adding the
automated backup oxygen system in the cockpit by the end of the year.
In
the meantime, the F-22s in Japan must fly under 44,000 feet so that the
flawed vests will not be required, and are on a 30-minute "tether,"
meaning they must be within 30 minutes of an emergency landing site. "While
we cannot eliminate risk from flight operations, we are confident the
F-22 is safe now and on a path to being as safe as any other fighter we
fly," Sholtis said. The Air Force says there have been no
breathing-related incidents in the F-22 fleet since March 8, though the
aircraft has marked more than 9,000 sorties, or 12,000 flight hours,
since then. "We won't ever bury anything if there are issues, but
so far, none," said Brig. Gen. Matthew Molloy, an F-22 pilot and
commander of the 18th Wing on Japan's Kadena Air Base. "This airplane is
absolutely vital to our national security."
The F-22's woes have
been especially troubling for the Air Force because it is in many ways
its showcase aircraft - and its most controversial. At $190 million
apiece, not counting development costs, it was lambasted in Congress as
an overpriced luxury item not suited to current conflicts. But the
flurry of investigations into its safety problems have also revealed a
more fundamental issue within the Air Force itself: decades of
budget-cutting and outsourcing that severely compromised its expertise
on what kinds of physiological problems pilots might face when flying in
the extremely demanding conditions posed by its most advanced aircraft. "Over
the past 20 years, the capabilities and expertise of the USAF to
perform the critical function of Human Systems Integration have become
insufficient," Gregory Martin, who led the study into its oxygen
problems for the Air Force Scientific Advisory Board investigation that
began in 2011, told the House subcommittee.
Martin said the
program's decline cost the Air Force expertise on life support systems,
altitude physiology and pilot health and safety. He said that was
compounded by "inadequate research, knowledge, and experience for the
unique operating environment of the F-22." Maj.
Gen. Charles Lyon, the Air Combat Command's director of operations,
concurred with those conclusions at a news conference last month. "We
probably overshot the mark on how much downsizing we did in this study
of physiology," he said. Divers considers the demise of RAW-G to be emblematic of that decline. "The
RAW-G became a brain trust, for sure, and it pushed various things that
otherwise would have been completely ignored or not even brought up as
an issue," Divers said. "All of that died in 2007."
Source : http://news.yahoo.com
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