'Excessive' rubbing of engine blades caused F-35 failure: Pentagon

LONDON Sun Jul 13, 2014 2:40pm EDT

An F-35 life-size model aircraft is displayed at the 2014 Farnborough International Airshow in Farnborough, southern England July 13, 2014.   REUTERS/Kieran Doherty

An F-35 life-size model aircraft is displayed at the 2014 Farnborough International Airshow in Farnborough, southern England July 13, 2014.

Credit: Reuters/Kieran Doherty

LONDON (Reuters) - The engine failure that has grounded the entire fleet of Lockheed Martin Corp F-35 fighter jets was caused by "excessive" rubbing of fan blades in the plane's Pratt & Whitney engine, but does not appear to be a fundamental design flaw, the Pentagon's chief weapons buyer said on Sunday.

Defense Undersecretary Frank Kendall told reporters on Sunday there was still a chance that the grounding order could be lifted in time for the F-35 to make its international debut at the Farnborough air show.

Organizers of the show confirmed that the F-35 would not appear on Monday, but said it could still arrive and fly later in the week.

The United States' newest combat jet had already been pulled out of a British military show last week, after the entire fleet was grounded following a massive engine failure on a U.S. Air Force F-35 at a Florida air force base on June 23.

Kendall said the grounding had halted testing but he did not view the incident as a "fundamental setback" for the $400 billion program, the Pentagon's biggest, which still has about 40 percent of developmental testing to complete.

He said the engine had suffered two issues involving fan blades in the past few years, but they appeared unrelated and not systemic to the airplane.

"None of those things that have happened, including this recent one as far as I know, suggests that we have a fundamentally flawed design," Kendall said.

He said detailed inspections of engines on the fleet of 97 F-35s already built had not shown signs of the kind of excessive rubbing founded on the engine that broke apart, although there were signs of milder rubbing in several other engines.

Kendall said the evidence being compiled did not point to a systemic issue, but the analysis was still going on. In this case, engineers found evidence of significant rubbing by the fan blades against a cowl.

"We’re not noticing it throughout the fleet," he said. "The design allows for a limited degree of rubbing, but it was enough in this case to cause a structural reaction that ultimately led to failure."

Bennett Croswell, president of Pratt & Whitney's military engine business, declined comment on any details about the engine failure and what caused it.

Marillyn Hewson, chief executive of Lockheed Martin, said it was disappointing that the jet had not flown in Britain thus far, but the company stood ready to support the jet if flights were allowed to resume.

She said military officials from other countries were supportive of the process now under way.

"People who understand the nature of development take this in stride as normal discoveries in development," Hewson said.

(Additional reporting by Mark Potter; Editing by Kevin Liffey)

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Comments (22)
AZ1811 wrote:
The biggest piece of “pork” in the pentagon arsenal. Almost every senator or congressman has a piece of the pie in the construction of this flawed, and already surpassed by the Chinese, piece of military industrial complex junk. This plane is not what it is portrayed to be and will be obsolete before testing is complete. Way to go congress.

WAKE UP America – this is an expensive piece of junk “pork”.

Jul 13, 2014 3:00pm EDT  --  Report as abuse
pk47 wrote:
If the GE/Rolls Royce F136 engine was allowed to proceed as an alternative to the F135, then none of these engine problems would cause as much anxiety. The funny thing is that the net saving was a mere $1.8 Billion in a $400 Billion program, or less than 0.045% savings.

Jul 13, 2014 3:23pm EDT  --  Report as abuse
RMax304823 wrote:
Wikipedia: “In February 2011, the Pentagon put a price of $207.6 million on each of the 32 aircraft to be acquired in FY2012, rising to $304.15 million ($9,732.8 million ÷ 32 aircraft) if its share of research, development, test and evaluation (RDT&E) spending is included… As of 2012, problems found in flight testing were expected to continue to lead to higher levels of engineering changes through 2019. The total additional cost for concurrency in the program is around $1.3 billion. By the next year the cost had grown to $1.7 billion.”

If things work out, the fleet may be fully deployed by 2037.

Everything about it makes it sound like a piece of junk whose chief purpose is to provide jobs for the constituents of congressmen.

If this isn’t the “military/industrial complex” that Eisenhower warned us about — then what is?

Jul 13, 2014 3:43pm EDT  --  Report as abuse
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