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Resident Curmudgeon
Military Professional
Join Date: 03-12-05
Location: Panama City Fl
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Raptor problems
Two articles about 2 different problems
Forward Boom Frames
http://66.21.108.67/interconnect/browser/intercon.dll
Quote:
TITLE:Flaw could shorten Raptors’ lives
SECTION:Local
PUBDATE:May 2, 2006
HEADLINE:Flaw could shorten Raptors’ lives
BYLINE:By Ed Offley
CONTACT:News Herald Writer 747-5079 / eoffley@pcnh.com
TEXT:The F-22A Raptor has been designed with a service life of 8,000 flying hours, but a faulty manufacturing process discovered four months ago may cause a key structural component in 90 of the new fighters to age prematurely, officials said Monday.
The “forward boom frames” in the 62-foot-long fighter are constructed of titanium, a lightweight but extremely strong metal, and are used to anchor the aircraft’s wings to its fuselage, said Air Force spokesman Doug Karas. During routine testing in December, Karas said, officials discovered that the titanium components may have been “improperly” treated, creating the possibility that the metal would not last as long as it is supposed to.
The flawed components, Karas said, “do not affect safety of flight and, consequently, no restrictions have been put on F-22 flight operations.”
The problem affects Raptors No. 4017 through 4107, including most of the 66 Raptors that already have been delivered to the Air Force and several dozen more still being manufactured, Karas said. There are 23 Raptors assigned to Tyndall Air Force Base for F-22 pilot training with another six scheduled to arrive in the next year.
“This is not a result of improper design, but an issue with one supplier’s manufacturing process,” Karas said in a statement to The News Herald.
A spokesman with the Lockheed Martin Corp., prime contractor for the F-22, said Monday the company is working closely with Air Force experts to determine the extent of the problem. Structural tests including “fatigue” tests of the fuselage booms are continuing, said company spokesman Joe Quimby.
Under a “heat treat” process, the titanium boom frames are raised to a high temperature in order to “achieve the desired grain structure” in the metal, Karas said. “A section of the forward boom frames under investigation may not have been held at this temperature long enough” to reach the targeted strength, he said.
The trade publication Defense News reported Monday that it will cost about $1 billion to fix the flawed boom frames, but both Karas and Quimby flatly denied that allegation.
Raptor program officials also have identified the need to reinforce the aft boom in 41 of 73 Raptors to strengthen the juncture where the tail is attached to the fuselage, according to Air Force officials quoted by Defense News. (Of those 73 aircraft, 66 also are affected by the forward boom heat-treatment flaws, officials said.)
An Air Force spokesman told Defense News that the discovery occurred as part of the normal testing process for each new aircraft design.
“As the aircraft come down the production line, they continue to test the fleet,” said Maj. Keith Scheirmann, chief of Raptor heavy maintenance and modifications at Wright-Patterson Air Force Base. “Sometimes, we find areas where we want to go back and enhance the capability or upgrade the aircraft,” he told the publication.
Still, fixing the problem in each airplane could require removing the wings to inspect the boom area, a time-intensive and expensive process, officials said.
The Air Force and Lockheed Martin are conducting further tests at a company facility to determine the severity of the problems and hope to have answers by the end of May.
The Defense Department and Congress have agreed to cap the F-22 program at 183 aircraft. Lockheed Martin has contracts to build another 107 of the advanced fighters, Quimby said.
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And the Aft Boom
http://aimpoints.hq.af.mil/display.cfm?id=11067
Quote:
US Air Force sees $100 million to fix F-22 problem
BY: unattributed, Reuters News Service
05/04/2006
WASHINGTON, May 2 (Reuters) - The U.S. Air Force on Tuesday said it would cost about $100 million to fix structural weaknesses discovered in 73 radar-evading F-22 fighter jets built by Lockheed Martin Corp. (LMT.N: Quote, Profile, Research).
Air Force spokesman Doug Karas denied a report in Defense News, a respected weekly industry publication, which said the repairs affected 100 aircraft and would cost $1 billion.
He said the planned retrofit involved strengthening the aft boom, where the horizontal tail of the plane attaches to the fuselage. Some 41 aircraft would be retrofitted beginning in January to fix the weakness, while improvements to 32 more jets would be incorporated into the production line, Karas said.
Of those planes, 66 were also affected by a separate issue involving the plane's forward boom, where the wing attaches to the fuselage, where fatigue testing revealed that titanium used there was not properly heat-tested.
Karas said the problems did not affect the flight safety of the planes, and a study was underway to determine what needed to be done about that issue and any potential costs. Results were expected later this month.
The Pentagon's latest figures put the cost of the F-22 fighter jet program at $62.6 billion, including research and development. Current plans call for producing 183 jet.
Lockheed said it continued testing and research on the F-22, but gave no details on the reported structural problems.
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