The Space Shuttle Orbiter had a flight mode whereby, at or below ~50,000 feet of altitude during the reentry (or, in the event of an ascent abort, the gliding, unpowered phase of flight), the commander could command an autopiloted, wings level glide at about 190 knots equivalent airspeed (KEAS).
The plan was then, while the Orbiter was gliding, that the crew could execute a manual bailout procedure via the side hatch, utilizing the egress pole system. Said bailout could be initiated at or below ~30,000 feet of altitude during the glide.
Said bailout procedures were initiated after the Challenger mishap.
To reference some of the bailout procedures (what we called a "Mode 8 egress"), please see the Shuttle Crew Operations Manual (page 2.10-13 for information about the Egress Pole System and starting on page 2.10-18 for information about the crew bailout procedures).
FYI, the 190 KEAS figure I stated above is from a crew training workbook that I still have on hand - specifically, there is a depiction therein of the "BAILOUT MODE 8" crew cue card that states (among other things) that the commander is to take manual control of the Orbiter, establish level flight, then, as the airspeed bleeds down to 185-195 KEAS, is to engage the autopilot. Said autopilot would then establish a glide at about those airspeeds.