Complex sentence: The term "uncontrolled decompression" here refers to the unplanned depressurisation of vessels that are occupied by people; for example, an pressurised aircraft cabin at high altitude, a spacecraft, or a hyperbaric chamber.
Split into simpler sentences: The term "uncontrolled decompression" here refers to the unplanned depressurisation of vessels that are occupied by people. For example, an aircraft cabin at high altitude, a spacecraft, or a hyperbaric chamber.