Event Description
During climb through 1,600 feet, the upper half of the main cabin entry door opened and separated from the Aerostar. The pilot, a physician, stated he was reasonably sure he had secured the door before departure. Although the cabin had not yet pressurized, the door seal had inflated, and the cabin was set to pressurize at 2,000 feet.
Door Recovery and Examination
The separated door was recovered from a mobile home park, where it had struck a mobile home. Examination revealed that the four locking pins were extended, or in the locked position. Investigators could not determine why the door opened.
Background
Since 1980, Aerostar aircraft have been involved in four accidents and eight incidents in which the main cabin entry door opened in flight. One of those accidents resulted in a fatality. On April 12, 1988, the National Transportation Safety Board recommended that the Federal Aviation Administration issue an Airworthiness Directive to address the problem.