> Four CAPS deployments occurred successfully at higher speeds, 168, 171, 187 and 190 knots indicated airspeed, and one deployment failed at an airspeed estimated at over 300 knots airspeed.
* https://www.cirruspilots.org/Safety/What-Is-CAPS
Anything lower than that will forward-motion stop the aircraft. AFAICT, there is a need for 2000' (650m) of altitude above the ground for the system to deploy in time to be useful (slow descent).