Aircraft
F-35 Program Completes Last Developmental Test Flight
There have been no serious mishaps—except for the cost.
The final SDD flight was completed by an F-35C testing the external carriage of GBU-31 2,000-pound Joint Direct Attack Munitions (JDAMs) and AIM-9X Sidewinder air-to-air missiles. (Photo: Lockheed Martin)
The final SDD flight was completed by an F-35C testing the external carriage of GBU-31 2,000-pound Joint Direct Attack Munitions (JDAMs) and AIM-9X Sidewinder air-to-air missiles. (Photo: Lockheed Martin)

Lockheed Martin declared that the F-35 program had completed the “most comprehensive flight-test program in aviation history.” The last sortie in the System Development and Demonstration (SDD) phase took place from NAS Patuxent River, Maryland, on April 11, when F-35C CF-02 collected data on loads that are generated by external carriage of some weapons. According to the U.S. Government Accountability Office (GAO), the SDD phase has cost more than $60 billion, a 50 percent increase on that predicted when SDD started in December 2001 (in FY2017-adjusted dollars).