-- An interior bulkhead that fits around the jet's Pratt & Whitney F135 engine and extends into the wings has been redesigned because of cracks in it discovered after 1,500 hours of durability testing. The bulkhead in question is titanium in the conventional and carrier versions of the aircraft but aluminum in the B variant to save weight. The redesigned bulkhead has been installed in the 24th F-35B built and corrections will be retrofitted into the first 23 B variants, five of which are being used in tests and the rest of which are in various stages of production.
-- Devices that operate the roll post nozzles were overheating when the F-35B hovered or flew forward at less than 60 knots, or about 75 mph, in vertical flight mode. These "actuators" are being insulated and the fix has been successful in flight test. Pratt & Whitney may change an adhesive used in the actuators to solve the excessive heating problem and obviate the need for the insulation in the future.
-- The drive mechanism that opens two Auxiliary Air Intake doors behind the clamshell lift fan door on top of the fuselage and holds them steady as the F-35B hovers or flies in vertical mode has been redesigned to be more robust and is being replaced. The change was made because turbulence created by the lift fan door causes the AAI doors to oscillate excessively with the current drive mechanism, making them likely to wear out too soon.
-- The driveshaft that runs from the engine to the lift fan to turn its blades has proven to fit imperfectly into its designed space by an "infinitesimally small" amount, as Amos described it. This means mechanics may have to pre-stress the part to install it. That creates problems when the shaft expands and contracts due to changes in its temperature as the aircraft warms up in flight. A thin steel "spacer," shaped something like a washer and about the diameter of a volleyball, has been incorporated to make the driveshaft fit better in the fifth F-35B variant as an interim fix. A redesigned driveshaft will become a standard production part beginning in early 2014.
-- Improved cooling and temperature monitors have been added to ensure safe operation when lift fan clutch plates that sometimes drag against one another during normal flight produce excessive heat. Adjusting the distance between the clutch plates is expected to solve take care of the problem.
And the wing rebuild for A and B models. Looks like the assumptions from the results of the 2004 SWAT effort were overly optimistic.
But our second land army says it needs the F-35B. Even if the U.S. could do a war and never miss STOVL fighter ability.
That is if we can afford to go to war.
"We still are going to be a global power," he said. Although there may be some commitments around the world that the military will not be able to do with less funding, it must be able to give the president the option of responding to international conflicts or humanitarian assistance situations.
We tried that in the 1990s. It didn't go so well. And then, we were not staring at trillions of unworkable debt.
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