Glossary: Press Review

This glossary explains the key technical terms and abbreviations used in this chapter.

Abbreviation / Term	Explanation
Block 4	Next major software modernisation phase of the F-35. Massively delayed.
GAO	Government Accountability Office — US government audit office.
TR-3	Technology Refresh 3 — hardware upgrade of the F-35. Prerequisite for Block 4.

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As of March 2026. All information is based on publicly available sources.