What happened
On 19 April 2010, a Socata Tobago TB-10, registration PK-AGU, was conducting touch-and-go training maneuvers at Budiarto Airport in Indonesia. The flight was operated by the Indonesian Civil Aviation Institute and carried a flight instructor and a student pilot.
During the second circuit of the training session, the aircraft experienced a bounce upon landing and drifted toward the left side of the runway. During this maneuver, the aircraft struck a moving motorcycle that had entered the runway area. The impact caused the aircraft to overturn on the left side of runway 30, approximately 65 meters from the centerline. The collision resulted in the deaths of two motorcycle riders and the flight instructor, who succumbed to his injuries three months later. The student pilot sustained serious injuries.
The investigation
The investigation focused on the presence of unauthorized vehicles on the active runway and the security protocols at Budiarto Airport. Investigators established that the motorcycle had entered the runway through holes in the airport's perimeter fencing. Local residents were reportedly using the airport grounds as a shortcut to reach a nearby main road.
Furthermore, the investigation examined the response of the Air Traffic Control (ATC) tower. While the controller observed the motorcycle on the airside, they assumed the vehicle would move away and did not activate the emergency crash bell. Additionally, it was noted that the ATC transcript recorder was unserviceable at the time of the accident, and the airport's security standard operating procedures were found to be lacking specific details regarding aerodrome access control as required by regulations.
Findings
- The unauthorized movement of a motorcycle onto the runway was the primary cause of the collision.
- The aircraft was airworthy at the time of the accident.
- Security personnel were stationed at the main gates and the aviation institute, but no security officers were guarding the airside area.
- The airport perimeter fence had breaches that allowed local pedestrians and vehicles to access the runway.
- The ATC controller failed to trigger the emergency alarm upon seeing the motorcycle on the runway.
- The airport's security manual did not meet the required standards for controlling access to the movement area.
Safety action
Following the accident, the Budiarto Airport Authority initiated several security coordination efforts involving local police, military, and community leaders. Efforts were made to reinforce the airside fencing and improve the security of the runway boundaries to prevent further unauthorized entries.