N14056 - 1988 Aircraft Aircraft Registration

The failure of the flight crew to perform the cabin pressurization manual control abnormal checklist after experiencing a pressurization system malfunction and switching to manual pressurization control, and the failure of the flight crew to perform the emergency landing checklist prior to landing, resulting in the airplane having an excessive cabin pressure level after landing which led to a rapid decompression of the airplane when a flight attendant opened door and was ejected out of the airplane during emergency evacuation that was initiated by the captain. Contributing to the accident was the failure of operator maintenance personnel to ensure that insulation blankets around the forward and aft outflow valves were properly secured in accordance with airplane manufacturer's data, resulting in a malfunction of the pressurization system. Other contributing factors include the absence of FAA requirements that each emergency exit door has a system to relieve pressure or contain specific warnings (such as lights, placards, or other indications that clearly identify the danger of opening the emergency exit doors when the airplane is over pressurized); the absence of FAA technical specifications for lavatory ionization smoke detectors; the absence of a requirement in the airplane's ground/emergency evacuation checklist for the flight crew to ensure that the cabin differential pressure is zero pounds per square inch before signaling flight attendants to begin an emergency evacuation; and the absence of a mechanical stop in the negative direction on the cabin altimeter gauge.