Pentagon Develops F-35's 4th Generation Software

F-35 Joint Strike Fighter officials are in the early phases of mapping out a fourth software drop designed to ensure the fifth generation fighter can counter threats and weapons expected to emerge in the mid 2020’s and beyond, Air Force officials said.

“Block 4 will be that next block of software that we do. We will gather up all the requirements of what we need as a nation to counter the emerging threats that we can see even past what we can already do,” said Col. Carl Schaefer, the Air Force’s top Joint Strike Fighter integration official.

The fourth increment will build upon existing increments now in development, Schaefer added.

Many of the JSF’s combat capabilities are woven into developmental software increments or “drops,” each designed to advance the platforms technical abilities. There are more than 8 million individual lines of code in the JSF system.

Defense analysts and investigators said these lines of code poses the most significant risk to the timely development of the F-35. Delays in the software development will stall aircraft deliveries, the Government Accountability Office found.

Schaefer said many military officials with the JSF program disagree with the GAO’s March report.

“Challenges in development and testing of mission systems software continued through 2013, due largely to delays in software delivery, limited capability in the software when delivered and the need to fix problems and re-test multiple software versions,” the report states.

Schaefer said F-35 software development is largely on track.

Block 2B builds upon the enhanced simulated weapons, data link capabilities and early fused sensor integration of the earlier Block 2A software drop. Block 2B will enable the JSF to provide basic close air support and fire an AMRAAM (Advanced Medium Range Air to Air Missile), JDADM (Joint Direct Attack Munition) or GBU-12 (laser-guided aerial bomb), JSF program officials said.

The next increments, Blocks 3i will increase the combat capability even further and Block 3F will bring a vastly increased ability to suppress enemy air defenses.

The Marine Corps is planning to declare initial operational capability for its short-take-off-and-landing F-35B JSF by 2015 and the Air Force plans IOC with software block 3i in 2016, Schaefer said. Full operational capability will come with Block 3F, he added.

Block 3F will increase the weapons delivery capacity of the JSF as well, giving it the ability to drop a Small Diameter Bomb, 500-pound JDAM and AIM 9X short-range air-to-air missile, Schaefer added.

The AIM 9X is an Air Force and Navy heat-seeking infrared missile and the Small Diameter Bomb, or SBD, is a precision-guided, air-dropped Air Force bomb engineered with a next-generation seeker.  The SDB seeker uses what’s called a tri-mode seeker which can utilize millimeter wave radar, infrared guidance and semi-active laser technology, Raytheon officials said.

Block 4 will be broken down into two separate increments, Block 4A is slated to be ready by 2021 and Block 4B is planned for 2023. The first portion of Block 4 software funding, roughly $12 million, arrived in the 2014 budget, Air Force officials said.

“Block 4 will include some unique partner weapons including British weapons, Turkish weapons and some of the other European country weapons that they want to get on their own plane,” said Thomas Lawhead, operations lead for JSF integration office.

Lawhead added that Block IV will also increase the weapons envelope for the U.S. variant of the fighter jet.  A big part of the developmental calculus for Block 4 is to work on the kinds of enemy air defense systems and weaponry the aircraft may face from the 2020’s through the 2040’s and beyond.

“Coming up with requirements always starts with the threat. How are we going to meet national security objectives in the future?  Based on those objectives we look at the threat and then we decide how we are going to counter the threat,” Schaefer said.

The rationale for the Block 4 software increment is to keep pace with technological change and prepare technology for threats likely to emerge 20 years into the future, Schaefer and Lawhead explained.

“If you look back to 2001 when the JSF threat started, the threats were mostly European centric – Russian made SA-10s or SA-20s. Now the future threats are looking at more Chinese-made and Asian made threats. Those threats that are further out are the ones that are being focused on for Block 4,” Lawhead said.