In the case of the jetpack the parachute is launched upward with rockets. This takes extra time: the time it would take for the operator or system to detect en

In the case of the jetpack the parachute is launched upward with rockets. This takes extra time: the time it would take for the operator or system to detect engine-out and initiate parachute launch, then the time it would take for a rocket(s) to launch the parachute up to where it could be, then the time for the uprush of air to catch the canopy. Here's a link to an article about the ballistic parachute fitted to Cirrus SR20/22 aircraft. http://www.cirruspilots.org/content/CAPSHistory.aspx http://www.cirruspilots.org/content/CAPSHistory.aspx There's one mention of a low-altitude parachute deployment: "one activation occurred at too low an altitude to fully inflate the canopy (witnesses report 200 feet above ground), and another activation where the rocket took an unusual trajectory resulting in a failure to open the canopy."