Block 4 / TR-3 Modernisation Crisis

¶ B7. Block 4 / TR-3 Modernisation Crisis

¶ Update through 6 September 2026

Modernisation, GAO follow-up in July 2026: The Block 4 cost-transparency recommendation remains open. Technology-readiness and engine-upgrade reviews are planned for December 2026, not completed. This updates recommendations from a 2023 report. GAO-23-106047

¶ Historical archive

¶ Key Figures

Block 4 costs: 10.6 billion (2018) -> 16.5 billion (2023) -> unknown (2025)
Completion: 2026 (original) -> 2029 -> 2031+ (current)
TR-3 delivery halt: July 2023 - July 2024
Block 4 will be "truncated" -- scope reduced (September 2025)