The Telegraph reports:
The production of the F-35 Joint Strike Fighter – the world’s most sophisticated and expensive combat aircraft – has been derailed after engineers discovered that the jet’s fuel tank could explode if struck by lightning.
Attempts to increase fuel efficiency by reducing the jet’s weight have also made it more vulnerable to enemy attack than the generation of aircraft it was supposed to replace.
The damaging findings were disclosed in a Pentagon document which revealed that a fault within the JSF’s fuel tank could potentially lead to catastrophic explosion if the aircraft was struck by lightning in a thunderstorm.
The report from the Pentagon’s Operational Test and Evaluation Office states that all test flying within 25 miles of thunderstorms is “not permitted” until a device in the fuel tank which maintains correct oxygen levels is redesigned.
The fear of an exploding fuel tank is just one of a series of problem to befall the F-35 programme. A design fault in the fuel tank has also prevented the JSF being able to rapidly descend to low altitude.
The Pentagon report describes both failings as “unacceptable for combat or combat training”.
Examinations by the United States Air Force and the Lockheed Martin, the aircraft’s manufacturer, also discovered a handful of cracks in the tested aircraft, including on the right wing and right engine of the F-35A variant, and on another part of the F-35B variant.
“All of these discoveries will require mitigation plans and may include redesigning parts and additional weight,” the report added.
. . .
Winslow Wheeler, at the US Center for Defense Information described the F-35 programme as a “gigantic performance disappointment”, which was not even as stealthy as the F-22 Raptor.
He added: “It’s the counterintuitive problem of paying a huge amount of money thinking you’re getting a Lamborghini or Ferrari: You’re not, you’re getting a Yugo (the cheap, mass-produced cars made in the former Yugoslavia).”
There's more at the link.
I've written extensively about the F-35 program, most recently in July last year, when I cited an in-depth report by Mr. Wheeler and concluded, "We can no longer afford this bottomless money pit. It's time to kill it before it drags the rest of the defense budget down with it." The report above does nothing to make me revise that viewpoint. The only consolation is that this country's deepening budget woes make it highly unlikely the F-35 will be bought in anything like the numbers forecast. It may not even make it into operational service at all, because it's simply unaffordable. If it does, its track record to date makes me doubt that it'll prove satisfactory.