Incident Overview
While parked at a gate, an aircraft rolled after the crew had set the parking brake. The captain had taxied the airplane into position, pulled the parking brake handle to the 'UP' position, and confirmed the parking brake light on the annunciator panel was illuminated. The seat belt sign was turned off, and the crew proceeded with their normal checklist.
Sequence of Events
During the checklist procedure, the crew heard a 'thud'. The captain looked up to see the aircraft moving. He immediately stopped the airplane by applying the brakes. After the aircraft was secured, a flight attendant informed the captain that three passengers had sustained injuries.
Maintenance Examination
Maintenance personnel examined the airplane and determined that no brake failure had occurred. The aircraft was subsequently released for continued service with no discrepancies reported.
Injuries and Damage
Three passengers were reported injured as a result of the unintended movement. The source does not specify the nature or severity of the injuries. There is no mention of damage to the aircraft or other property.
Probable Cause
The official investigation source provided by the aviation-safety editor does not state a probable cause for the incident. The report notes that the parking brake was set and verified, and maintenance confirmed no mechanical failure.