Constant BASE_DRAG_HIGH_TOP_MACH 

pub const BASE_DRAG_HIGH_TOP_MACH: f64 = 1.2;

The last Mach number where base drag is measured to read high: 1.2 (0.208 against MIL-HDBK-762’s 0.194, issue #68). Past it a flight’s warning adds the low side (BASE_DRAG_LOW_MACH); between the two the sign is unmeasured.