A developmental test team from the 461st Flight Test Squadron at Edwards AFB, Calif., flew the Technology Refresh-3 (TR-3) configuration of the Lockheed Martin [LMT] F-35 fighter for the first time on Jan. 6, the F-35 Joint Program Office (JPO) said on Jan. 10.

The F-35 JPO said that U.S. Air Force Maj. Ryan “BOLO” Luersen piloted tail number AF-7, “a specially instrumented flight test aircraft and the first with TR-3 upgrades installed.”

“He executed a functional check flight (FCF) profile to verify aircraft airworthiness and system stability,” the F-35 program said. “The 50-minute flight, which took the jet to 35,000 feet at speeds just shy of the speed of sound above the Mojave Desert, marked the start of an extensive flight test campaign. Developmental and operational test flights will continue through 2023 to ensure safety and prove warfighting capabilities.”

Last week, the Pentagon and Lockheed Martin said that it is uncertain when resumption of deliveries and flight acceptance testing of the F-35 will start, as the Naval Air Systems Command (NAVAIR) investigation of an F-35B mishap on Dec. 15 continues (Defense Daily, Jan. 3).

In the Dec. 15 incident, the pilot of a Lockheed Martin-owned F-35B ejected on the runway at Naval Air Station Joint Reserve Base Fort Worth, Texas.

On Dec. 30, Lockheed Martin said in a statement that the F-35 JPO and the company had finalized a Lot 15-16 contract that may be worth $30 billion to build and deliver up to 398 F-35s domestically and internationally. Those lots are to include TR-3.

Powered by the L3Harris [LHX] integrated core processor, TR-3 is the computer backbone for Block 4, which is to have 88 unique features and integrate 16 new weapons on the F-35, which became operational in July 2015.

“The TR-3 program has overcome technical complexity challenges with hardware and software, and is now on-track to deliver capability to the U.S. and its allies starting in 2023,” the F-35 program said on Jan. 10. “The government and industry team continue to find innovative ways to ensure delivery of critical capabilities to defeat future threats. Lessons learned in the execution of the TR-3 program will be applied across the entire Block 4 modernization program.”

Among the challenges that the F-35 program and industry have said that they are addressing is a parts shortage for the Northrop Grumman [NOC] AN/AAQ-37 Distributed Aperture System (DAS), which is to provide 360 degreee awareness for F-35 pilots from six infrared sensors that feed data to the pilot’s helmet (Defense Daily, Nov. 9, 2022).

Plans have called for the integration of the Raytheon Technologies’ [RTN] Next-Generation electro-optical DAS (EO DAS) into all F-35s beginning this year with Lot 15 under TR-3.

Northrop Grumman bowed out of a bid for the AN/AAQ-37 follow-on program in 2018, as company executives said that the pay-off would be higher for other business opportunities.

Last fall, Northrop Grumman said that it is on contract “to deliver [AN/AAQ-37] production units into 2023, and to support the system through sustainment contracts beyond that timeframe.”