Static-stability constraints

The Static Stability Requirements panel supports constrained or unrestricted altitude search. The source-defined defaults are:

Regime	Required minimum	Conditions
Subsonic	1.0 caliber	Mach < 0.8; applicable low-AoA samples
Transonic/supersonic	2.0 calibers	Mach ≥ 0.8; applicable low-AoA samples

The implementation uses post-rail flight data with absolute angle of attack below 5°, with explicit coverage handling. Mach 0.8 is a software-defined onset, not a verified reproduction of RASAero's internal warning boundary.

The default enabled option Require no native RASAero Marginal Stability warning adds an independent warning-free requirement. A completed flight with a marginal warning is distinct from a flight terminated because RASAero declares it unstable.

Feasible versus unrestricted

The best feasible design is the highest valid RASAero altitude among evaluated candidates meeting all configured requirements. The unrestricted winner may reach higher altitude but fail static or flutter screening. Neither design is necessarily a global optimum.

Assignment 14 example

One candidate at 21,163 ft was feasible with subsonic margin 1.796594 cal and transonic/supersonic margin 2.036817 cal, no native warning. The unrestricted winner at 21,638 ft was excluded from feasible selection due to marginal warning / stability requirements.

Static margin is a screening quantity, not proof of acceptable damping, structural integrity, or safe flight.

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Source basis: Assignment 14 review materials supplied with this documentation. Internal archive paths and raw evidence are not published.