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New F-35 Wing Problem Surfaces: Exclusive

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New F-35 Wing Problem Surfaces: ExclusiveUPDATED Washington: A new problem -- described in a Pentagon email as "not a serious issue" -- has been found with the wings of the Air Force and Marine versions of the F-35.

The problem is with the wing's forward root rib and was discovered in standard durability tests. The ribs -- which provide the core strength of the wings -- must be redesigned. The problem appears to be one stemming from design -- not quality control -- and a redesign production plan for the affected F-35 fleet's wings will be in place by the fourth quarter, a Capitol Hill source tells AOL Defense.
 
ur a bit slow...
they already fixed the problem.

F-35 Program Fixes Wing Problem

By DAVE MAJUMDAR
Published: 1 Sep 2011 17:40

Technicians with the F-35 Lightning II Joint Strike Fighter (JSF) program have found and corrected a problem with part of the aircraft's wing structure.

As part of the fifth-generation stealth fighter's test program, the jet's structure must be tested to ensure it meets its fatigue life requirement, a standard requirement for all new aircraft.

"During this analysis, a shortfall in the predicted durability life of the Conventional Take Off and Landing (CTOL) and Short Take Off and Vertical Landing (STOVL) wing forward root rib was identified," said JSF program spokesman Joe Dellavedova in an emailed statement.

Lockheed Martin is leading an international program to develop and manufacture the single-engine stealth combat jet for the U.S. Navy, Air Force and Marine Corps and allied military forces.

The root rib is an aluminum part located where the leading edge of the aircraft's wing meets the jet's fuselage. It is required to have a life of 8,000 flight hours, and was slated to be tested to twice that, or 16,000 hours. But during testing, the root rib developed cracks at just 2,800 hours.

Program officials had suspected the problem, Dellavedova said, but proceeded with testing, in coordination with the U.S. Air Force, to gather more data.

"The crack is consistent with analytical predictions, both in terms of location and life," he said.

This sort of problem is not unusual in the development of any new aircraft, said Loren Thompson of the Lexington Institute, Arlington, Va.

In most aircraft programs, dozens of such problems are found and routinely corrected. That includes civilian aircraft such as the Airbus A380 and Boeing 787 airliners, Thompson said.

Dellavedova said the JSF program has developed retrofit plans and a redesigned full-life forward root rib for both variants.

"Resolving durability test article findings is a well-understood process. Durability testing is conducted early in the development of any new aircraft to avoid costly sustainment issues later in the life of the aircraft," he said. "Problems are found and corrected in development rather than fleet service."

In the meantime, the affected F-35s will be inspected regularly until they are retrofitted with the fix, as is always the case with any aircraft.

The new modified forward root rib design will be incorporated into production planes from the beginning of Low Rate Initial Production (LRIP) Lot 5 for both CTOL and STOVL aircraft. A total of 30 CTOL and 34 STOVL LRIP aircraft will need to be modified to fly for their full fatigue life.

This particular modification has been grouped with the existing retrofit requirements to reduce both the cost of the modification and the time that aircraft spend in deeper maintenance, Dellavedova said. It is expected that the forward root rib modification will take about 45 days to complete.
 
A newer and related article published by Wired.com

Senators Love Their Stealth Jet; Never Mind a New Design Flaw | Danger Room | Wired.com

Senators Love Their Stealth Jet; Never Mind a New Design Flaw

By David Axe September 6, 2011 12:00 pm

First, the good news: After a nearly monthlong flight ban, the Pentagon’s 20-strong Joint Strike Fighter test fleet is back in the air. The military and builder Lockheed Martin determined that the stealthy F-35 jet’s power system, while potentially flawed, did not justify the same prolonged grounding that has turned the Air Force’s 160 F-22s into $411 million hangar ornaments.

Now, the bad news: The test team has admitted another design problem with the $150-million airplane — a weakened wing structure. The admission is sure to fan the political flames raging around the $380 billion Joint Strike Fighter program, which aims to replace most of the existing Air Force, Navy and Marines fighters, but has been beset by delays, cost overruns, technical problems and questions over performance.

“The ‘defective’ aluminum beam was detected in November on Air Force and Marine Corps test aircraft after an unrelated bulkhead crack surfaced in the Marine Corps model,” Bloomberg reported. The problem reduces the lifespan of the F-35A and F-35B’s wing from 8,000 hours — roughly 25 years of operations — to just 1,200 hours, or around five years.

“This is not considered a serious issue,” F-35 spokesman Joseph DellaVedova said of the flimsy beam. Lockheed argues that the cracks could be considered a good thing, sorta, because the aluminum rib lasted 2,800 hours. But the Pentagon’s top testing official disagrees. Fixing the flaw will be a “difficult and complex process,” Michael Gilmore told Bloomberg. The cost of repairs will come out of the existing F-35 budget, potentially sapping funding for testing and production.


The revelation of the wing flaw could not have at a worse time for the Joint Strike Fighter, the costliest program in Pentagon history. In January then-Secretary of Defense Robert Gates put the Marines’ F-35B on two years’ probation after discovering structural flaws. In May, Ashton Carter, the military’s former chief weapons buyer, called the F-35’s projected trillion-dollar lifetime purchase and support cost “unaffordable.”

Two months later, Navy undersecretary Bob Work asked naval-aviation officials to weigh the implications of killing off either the Marines’ F-35B or the Navy’s F-35C. The Congressional super-committee tasked with cutting the nation’s trillion-dollar annual deficits is said to be considering deep defense cuts on top of the $400 billion in savings the Pentagon has already promised, only increasing the pressure on the F-35. Oh, and there’s also a major program review on the horizon.

Politicians with a stake in F-35 production clearly sense the mounting danger to the newfangled jet. Republican Sens. John Cornyn and Saxby Chambliss — respectively from Texas and Georgia, where most of the F-35 work is done — have both recently sent harshly worded letters to Pentagon officials demanding stronger support for the F-35. The Pentagon’s “failure to sufficiently defend and advocate for the program has enabled and even invited unwarranted criticisms,” Cornyn wrote.

But with the bad news apparently outnumbering the good, is the criticism truly “unwarranted”?
 
And those who have not can now dance in joy around the campfire.

Nothing wrong with that right? I'm sure the average Americans would rather have high quality, working and combat proven ones over defective ones any day of the week.
 
Nothing wrong with that right? I'm sure the average Americans would rather have high quality, working and combat proven ones over defective ones any day of the week.
True...And we also wish everything is perfect as well.
 

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