Function flags 

pub fn flags(
    max_mach: Option<Peak>,
    max_angle_of_attack_rad: Option<Peak>,
    min_powered_static_margin_cal: Option<Peak>,
    max_powered_moment_slope_per_rad: Option<Peak>,
) -> Vec<EnvelopeFlag>

The flags raised by a flight whose top Mach number is max_mach, whose largest counted angle of attack is max_angle_of_attack_rad, whose least static margin while a motor burns is min_powered_static_margin_cal, and whose largest static pitch-moment slope where that margin is undefined while a motor burns is max_powered_moment_slope_per_rad, in EnvelopeFlag’s order. Each holds on its own, so a flight past Mach 3.5 raises all three Mach flags, but of the two unstable flags only the first raised counts: a margin below zero wins over a moment slope above it. A NaN peak raises its flags, so a broken number can’t hide one.