Batllefield Tech

Software bugs causing turbulence for F-35 program

Air Force F35 fighter

Software flaws continue to plague the development of the F-35 Joint Strike Fighter, causing some operational tests to be scrubbed last year and software fixes to be put off until the next stage of the program, according to the annual report from the Pentagon’s top tester.

In a review last June of nearly 1,500 deficiency reports in relation to Block 2B of the fighter’s software, testers found 151 of them to be mission-critical, and said some of those deficiencies might not be corrected until the final version, Block 3F, is finished, according to the 2014 report on Defense Department programs from the Director of Operational Test & Evaluation (DOT&E).

Another ongoing source of concern has been what’s called mission data load software, which is specific to each mission and must work with the permanent bundle of software in each aircraft.

As a result of those software flaws and other complications—including a 2013 engine failure in an F-35A aircraft—not enough aircraft could be outfitted with the Block 2B configuration for the operational tests scheduled for 2014, Aviation Week reported. Those tests were dropped, in order to avoid delays that could have stretched into 2016, and further slowed down development of Block 3F. Instead, the program plans to run a reduced number of test points using F-35A test aircraft and defer some software fixes until Block 3 to try to keep the program on track.

With the reduced number of test points, developmental testing of Block 2B is expected to be finished in February, a bit earlier than DOT&E had expected. Those tests will determine whether which software deficiencies are corrected and which are deferred until Block 3F, the report said.

The F-35, the most expensive and complex weapons system ever developed, is intended to replace the military’s F-16, A-10, F/A-18 and AV-8B fighters, and be used by the Air Force, Marine Corps, Navy and forces of 10 or more other countries. Plans call for three variations of the fighter, which will share most of the same components but will be tailored for different uses: the F-35A for conventional take-off and landing, the F-35B for short-take off and vertical-landing, and the carrier-based F-35C.

In August, the program enlisted the Army Aviation and Missile Research Development and Engineering Center’s Software Airworthiness and Safety Lab, known as SASL, to perform independent software safety analyses for the F-35.

About the Author

Kevin McCaney is a former editor of Defense Systems and GCN.

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