this is for the techies on the forum.

In no particular order,  current list for the top 8 list of F-35B problems and solutions are on the jump:

1. Bulkhead cracks

The Problem: It was revealed in November that the aluminum alloy 496 bulkhead cracked less than 10% through a 16,000hr durability test.

The Solution: In the short-term Lockheed has redesigned a hard edge for the bulkhead into a curve. By redistributing the load, the 496 bulkhead will remain airworthy for 1,500h. That’s plenty of time for the test fleet, but operational aircraft need a load-bearing bulkhead to survive at least 8,000h. As a result, Lockheed is planning to install a 7-8lb steel patch on the bulkhead for production aircraft. A composite patch is also being studied.

2. Vertical lift bring-back (VLBB)

The Problem: As Lockheed defines it, the F-35B right now has all the vertical thrust it needs to “bring back” the required load of weapons and fuel onto an amphibious carrier. But today’s lifting capacity won’t be enough as the F-35B’s weight is expected grow like any other operational aircraft.

The Solution: It’s not exactly clear how much weight is in the trade space. Lockheed only says that 400lb is “a lot” in the context of a VLBB debate. Meanwhile, Pratt & Whitney has offered to increase the vertical thrust of the F135-PW-600, which is the STOVL variant, by around 200lb, if necessary. Lockheed prefers to reclaim the VLBB growth margin by putting the F-35B’s structures and systems on a diet. 

3. Auxiliary air inlet (AAI) doors

The Problem: Three doors open to allow air to flow into the F-35B’s engine. The big one is the one-piece door after of the cockpit — internally nicknamed the ’57 Chevy hood. Just behind that doors are the auxiliary air inlet doors. As the amount of ram air declines as the F-35B slows to a hover, the auxiliary inlet sucks more oxygen into the liftfan engine, which increases vertical overall thrust. The problem is that the hinges for the doors are too weak for the turbulent air at 250kt.

The Solution: The near-term fix is to change the software so the AAI doors can’t open until the F-35 slows down from 250kt. The long-term fix is redesign either the doors or the hinges to survive the turbulent air at higher speeds. Lockheed believes this will be a relatively simple fix because both the doors and hinges are easily accessible.

4. Parts reliability

The Problem: The F-35B’s parts reliability is poor, even for a program at this stage of development. Complaints have been hears about everything from key components of the propulsion system to the rudder pedals.

The Solution: In the short term, Lockheed is simply ordering more parts stockpile. As this tends to increase costs without addressing the root problem, Lockheed also has a long-term plan. In the latest restructuring unveiled in January, Lockheed and it’s key suppliers will receive new contracts to make investments to improve reliability of the thousands of parts and components.

5. Wing roll-off

The Problem: At transonic speeds — generally between 0.95M and 1.05M — air flow for any supersonic fighter starts getting “squirrelly”, as pilots call it. In this regime, air can be flowing over one wing or parts of one wing at supersonic speed, while moving subsonically on the other wing. This is especially true when the fighter is maneuvering aggressively. In such disruptions, one wing has a tendency to “roll-off”, a movement not quite as severe as the “wing drop” problem experienced by the Boeing F/A-18E/F Super Hornet and still on the list of concerns for the F-35C carrier variant. The F-35B has experienced wing roll-off in flight tests, which Lockheed says was expected.

The Solution: The F-35 is a fly-by-wire aircraft, so the plan is to counter the wing roll-off with a software change that sharpens the responses by the flight controls when such events occur. This is not expected to solve the problem completely, but it needs to be better. “You’re never going to be perfect in that regime, but itneeds to be acceptable,” Lockheed says.

6. Driveshaft:

The Problem: The driveshaft that transfers power from the engine to the liftfan met Lockheed’s performance target, but flight tests revealed the original requirement wasn’t enough, according to Pratt & Whitney. As a result, the driveshaft is stretching and compressing at higher than expected levels.

The Solution: The near-term fix has been to insert spacers at each end of the shaft, allowing the component to expand more as heat rises. In the long-term, P&W is redesigning the driveshaft to meet higher tolerances for expansion and contraction.

7. Roll-post nozzle:

The Problem: Actuators the move the roll-post nozzles embedded inside each wing are burning out faster than anticipated. The cause is not the design of the actuator itself. Instead, the temperatures inside the wing are hotter than expected, so the actuators are exposed to unexpected levels of heat.

The Solution:  In the near-term, more insulation is being installed around the actuators, and ventilation in the wing is being improved. In the longer-term, Pratt & Whitney will upgrade the actuator design to survive more hotter temperatures.

8. Lift-fan clutch

The Problem: According to Pratt & Whitney, it happens “very infrequently”, but somehow the clutch plates for the lift-fan touch in flight. This creates friction that exceeds the clutch’s temperature limit.

last year2013 lockheed martin laid off workers over this  rubbish aircraft.

do you remember in the seventies british leyland made a car called the TR7, they also made the TR8 for the american market, both these cars where rubbish...

all bad design faults,just like lockheed u.k.  who made the brake systems for  these vehicles,in the u.k.

lockheed martin will be the maker of the rubbish F-35 aircraft in america.

history repeating here again.


wake up people of australia.

the F111 has a host of problems.  they were fixed.  get over it.

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It should have two engines instead of one for higher lift capacity and better reliability and redundancy. This is proof that it is a toy.

Australia has no evident prospective enemies. May as well buy these flying coffins to keep the military happy.

Should remain airworthy until after the cheque clears.

Setanta wrote on Apr 25^th, 2014 at 12:17am:


I see a problem there:
   Israel has a committed and resourceful leadership, we have Abbot and his ilk.
  Israel has an experienced and determined military establishment with promotion by merit, we have...well, what we have, with promotion by politicking and arse kissing.
Ain't gunna happen mate, more's the pity.

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You meant Leyland P76 .... that was the lemon car here.