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