The mechanism: Since January 2024, the FAA has kept Boeing's 737 MAX final-assembly rate under a hard regulatory cap — a direct response to the Alaska Airlines door-plug blowout. That cap has been anything but static. The agency lifted the original 38-per-month ceiling in early 2026 after Boeing sustained the rate for months, approved a step-up to 42 per month, and in late May 2026 signed off on Boeing's capstone review for rate 47. Each of those approvals is a discrete, documented regulatory event — not a vague market mood — and each one mechanically increases the number of shipsets of engines, castings, and fasteners that must flow through the supply chain every single month. That makes FAA rate letters one of the cleanest policy-to-revenue transmission mechanisms in industrials: a government approval that translates almost one-for-one into supplier shipment volume.