Incident Description
The event took place while passengers were exiting an aircraft that was secured with chocks and the seat belt sign turned off. A belt-loader operator drove the vehicle toward the airplane to service it. The operator first tested the brakes and confirmed they were working correctly. As the loader approached to within approximately 3 to 4 feet of the fuselage, the operator again applied the brakes. This time, however, the brakes either jammed or became stuck and did not respond. The operator quickly shifted the transmission into neutral, but the vehicle continued to roll forward. The loader subsequently struck the aircraft's fuselage, causing damage.
Operator Actions and Statements
The operator reported that he did not think to engage the emergency brake during the incident. He had no prior indication of a brake issue, as the initial test was successful. The sudden brake failure appeared to be an isolated occurrence.
Inspection Results
Following the accident, maintenance personnel performed a thorough examination of the belt-loader. The inspection included checks of the brake system, transmission, and other components. The results showed no mechanical anomalies or defects that could explain the brake failure. The vehicle's systems were found to be in normal operating condition.
Conclusion
The collision resulted from the unexpected unavailability of the service brakes during the final approach to the aircraft. Despite the operator's attempts to halt the loader, it made contact with the airplane. The reason for the brake failure remains undetermined, as no mechanical cause was identified.