The F-35 Joint Program Office (JPO) has developed Block 3i software that is claimed to provide the US Air Force's F-35 Lightning II stealth multirole fighter with initial warfighting capability on upgraded computer hardware.
With the new software, the F-35s have shown stability three times better than the original 3i software and approximately twice the level of stability as the previously fielded Block 2B software.
The entire aircraft fleet of the USAF will be upgraded to the new version of 3i software and 2B software by the end of this year.
As of 1 May, the F-35 with the 3i software had flown more than 100 flight hours.
The JPO has been working for the past few months to fix the stability issues in the original software.
The instability in software caused the shutdown of sensors once every four hours in Lockheed Martin's combat aircraft, thereby increasing the number of reboots in flight.
The cause of the issue was the timing of software messages from the sensors to the main F-35 fusion computer.
The F-35 programme will now focus on completing Block 3F, the full warfighting capability software.
The improvements to Block 2B and 3i have been transferred to Block 3F, and all developmental test aircraft and labs have been upgraded to Block 3F.
The F-35 aircraft has approximately eight million lines of code, in addition to another 16 million lines of code on the off-board systems.
The aircraft is being developed in three models including the F-35A conventional takeoff and landing (CTOL) variant, the F-35B short take-off and vertical-landing (STOVL) variant, and the F-35C carrier-based catapult assisted take-off but arrested recovery (CATOBAR) variant.
Image: The US Air Force's F-35 Lightning II stealth multirole fighter. Photo: courtesy of Lockheed Martin Corporation.