F-35 Joint Strike Fighter (JSF)

• The F-35 Joint Strike Fighter (JSF) program continues to have a high level of concurrency among production, development, and test.  Approximately 34 percent of the total planned flight testing, based on test points completed through  November 2012, has now been accomplished as the program  initiates the fifth of 11 initial production lots.  Durability testing is ongoing on all three variants, with only the F-35A test article having completed a full lifetime of testing.  The  program will not complete the two lifetimes of durability testing currently planned on any variant until the last quarter of 2014.

• Through November 2012, the flight test teams were able to exceed the flight rate planned for flight sciences in the F-35B and F-35C variants, but were slightly behind the plan for the F-35A.  The program did not accomplish the intended progress in achieving test objectives (measured in flight test points planned for 2012) for all variants.  Certain test conditions were unachievable due to unresolved problems and new discoveries.  The need for regression testing of fixes (repeat testing of previously accomplished points with newer versions of software) displaced opportunities to meet flight test objectives.

• The flight rate of the mission systems test aircraft also exceeded the planned rate during the year, but overall progress in mission systems was limited.  This was due to delays in software delivery, limited capability in the software when delivered, and regression testing of multiple software versions (required to fix problems, not add capability).  Test points accomplished for the year included Block 1 verification, validation of limited capabilities for early lot production aircraft, baseline signature testing, and Block 2 development. No combat capability has been fielded.

• The lag in accomplishing the intended 2012 flight testing content defers testing to following years, and in the meantime, will contribute to the program delivering less capability in production aircraft in the near term.

• The tables on the following page present the actual versus planned test flights and test points conducted as of the end of November 2012.

• The program submitted Revision 4 of the Test and Evaluation Master Plan (TEMP) for approval, which included changes to the program structure brought about by the previous year’s Technical Baseline Review and subsequent re-planning of testing.  However, the TEMP contained an unacceptable overlap of development with the start of operational test activity for IOT&E.

• The Air Force began the F-35A training Operational Utility Evaluation (OUE) in September 2012 and completed it in mid-November.  During the OUE, four pilots completed training in the system familiarization portion of the syllabus, which included no combat capabilities.  Because of the immaturity of the system, which is still largely under development, little can be learned about operating and sustaining the F-35 in combat operations from this evaluation.

• The program completed two of the eight planned system-level ballistic test series.  – The first series confirmed the built-in redundancies and reconfiguration capabilities of the flight-critical systems.  The second series indicated that ballistic damage introduced no measurable degradation in the F-35B propulsion system performance and that the damage would be undetectable by the pilot.  Ongoing analysis will evaluate whether these tests stressed the vulnerabilities unique to ballistic damage to the F-35 (e.g., interference or arcing between 270 Volt, 28 Volt, and signal lines and/or damage to lift fan blade sections).
– The first test series confirmed Polyalphaolefin (PAO) coolant and fueldraulic systems fire vulnerabilities.  The relevant protective systems were removed from the aircraft in 2008 as part of a weight reduction effort.  A Computation of Vulnerable Area Tool analysis shows that the removal of these systems results in a 25 percent increase in aircraft vulnerability.  The F-35 Program Office may consider reinstalling the PAO shutoff valve feature based on a more detailed cost-benefit assessment.  Fueldraulic system protection is not being reconsidered for the F-35 design.

• The program’s most recent vulnerability assessment showed that the removal of fueldraulic fuses, the PAO shutoff valve, and the dry bay fire suppression, also removed in 2008, results in the F-35 not meeting the Operational Requirements Document (ORD) requirement to have a vulnerability posture better than analogous legacy aircraft.

• Tests of the fuel tank inerting system in 2009 identified deficiencies in maintaining the required lower fuel tank oxygen levels to prevent fuel tank explosions.  The system is not able to maintain fuel tank inerting through some critical portions of a simulated mission profile.  The program is redesigning the On-Board Inert Gas Generating System (OBIGGS) to provide the required levels of protection from threat and from fuel tank explosions induced by lightning.


Download (PDF, 477KB)