Accident Overview
The airplane experienced an in-flight breakup while descending from flight level 240 (FL240). Investigation determined that the horizontal stabilizer, specifically the top of the T-type tail, had separated from the fuselage before impact with the ground.
Examination Findings
Examination of the wreckage revealed that 47 screw fasteners intended to attach the upper surface of the leading edge assembly for the left side of the horizontal stabilizer were missing. These fasteners had been removed the previous evening during scheduled maintenance.
Maintenance and Oversight Issues
Investigation found that mechanics, inspectors, and supervisors responsible for ensuring the airworthiness of the airplane the night before the accident did not comply with FAA-approved general maintenance manual procedures. Furthermore, routine surveillance of the maintenance department by the FAA was inadequate and failed to detect deficiencies that ultimately led to the accident. All 14 occupants were killed.
Probable Cause
The probable cause, as determined by the investigation, was the failure of Continental Express maintenance and inspection personnel to adhere to proper maintenance and quality assurance procedures for the airplane's horizontal stabilizer deice boots. This led to the sudden in-flight loss of the partially secured left horizontal stabilizer leading edge, resulting in an immediate severe nose-down pitchover and breakup of the airplane. Contributing factors included the failure of Continental Express management to ensure compliance with approved maintenance procedures and the failure of FAA surveillance to detect and verify compliance.