Software remains the biggest risk of the F-35 program, according to U.S. Air Force Lt. Gen. Christopher Bogdan, the program executive officer. In a presentation at the Air Force Association (AFA) Air & Space Conference on September 17, Bogdan also discussed progress in fixing the Joint Strike Fighter’s helmet-mounted display systems (HMDS), and program costs.

Lockheed Martin’s scheduled delivery of the full-capability Block 3F software in 2017 “highly depends” on the performance of interim Block 2B and 3I software releases, Bogdan said. Block 2B software, released for flight test in February, is the “initial warfighting” software that adds sensor capabilities missing from the training software releases, plus the AIM-120 air-to-air missile, GBU-12 laser-guided bombs and the GBU-32 Joint Direct Attack Munition (JDAM). Lockheed Martin plans to release Block 3F software to the services in 2017.

In a mandatory report to Congress last June, the Marine Corps said that it will achieve initial operational capability (IOC) with the F-35B in December 2015. In his AFA presentation, Bogdan said he is “confident” that the Marine Corps would achieve its planned IOC date. (He earlier told Vanity Fair magazine, which published a long article on the F-35 this month that there is nothing in U.S. procurement law to prevent the Marines declaring IOC before operational testing is complete.) The U.S. Air Force plans IOC of the F-35A version by December 2016, which is before the Block 3F software is available. The Navy plans to declare IOC of the F-35C carrier variant in February 2019.

Meanwhile, the F-35 program is continuing the development of two different helmet-mounted display systems (HMDS) from Vision Systems International (VSI) and BAE Systems after encountering problems with the original VSI system. While Lockheed Martin has reported progress in fixing the VSI system, the two systems will compete in a “fly off,” after which the program will choose one HMDS. Bogdan said there is a business calculation in resolving HMDS problems before making a final selection. Bogdan told Vanity Fair, “Lockheed Martin would very much like to influence my decision-making here in favor of the [VSI] helmet. I’m not letting them do that.” He told the magazine that the BAE helmet costs “$100,000 to $150,000 less.” According to Vanity Fair, the VSI helmet costs $500,000.

The development of the F-35 Joint Strike Fighter is being driven by a renewed effort to keep the acquisition and sustainment costs of the fifth-generation fighter “affordable,” Bogdan said at AFA. The program office has formed a “control unit” to track costs and is pressing F-35 contractors to weed out costs from their production processes. “By 2019 you are going to see an airplane…that would cost somewhat more than a fourth-generation airplane,” Bogdan said. “I have a commitment from Lockheed Martin, Pratt & Whitney, BAE and Northrop Grumman at the CEO level that they’re going to work together to drive down the cost of this airplane to make it comparable with a fourth-generation airplane.”