system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why can't commercial airplanes deploy Parachutes for use in case of emergency landings where all other manoeuvres or options to save the plane have failed?

Something similar to ELS - Earth Landing System (used by Spacecrafts / Shuttles for re-entry into Earth's atmosphere), an automated system that reacts to barometric sensors and timers to deploy chutes before hitting the ocean for a safe landing!
gpt
Some smaller planes are equipped with this exact thing. The issue is any parachutes big enough for a commercial jet would take up too much space and weigh too much to be practical for a commercial aircraft. They are already designed with so many failsafes that it simply isnt worth the money. Plus you would probably need multiple parachutes given how fast a jetliner flies. If you just deployed a main chute youd probably rip it right off the plane.