What happened
On 1 December 2010, a Socata TB-10 Tobago, registration PK-AGM, departed Budiarto Airport for a solo cross-country training mission. The flight, operated by the Indonesia Civil Aviation Institute, was intended to travel between Budiarto Airport and Radin Inten II Airport and return.
During the flight, the student pilot contacted Jakarta Approach to request a climb. While navigating the airspace near Soekarno-Hatta International Airport, the pilot requested to intercept a specific radial. However, radar monitoring indicated the pilot had crossed the desired radial twice, suggesting difficulty with instrument navigation. At 01:56 UTC, the pilot requested to return to base due to deteriorating weather. Shortly after this final communication, the aircraft disappeared from radar tracking.
The wreckage was later located in Banten Bay. The impact was characterized by high speed and a steep angle, resulting in the fatal loss of the student pilot and substantial damage to the aircraft.
The investigation
Investigators from the KNKT examined the wreckage and flight data, noting that the engine was still running at the moment of impact, as the propeller had detached from its shaft. The severity of the structural damage, including a deformed wing root and a detached pilot seat, indicated the aircraft was in a spin dive upon hitting the water.
The investigation also reviewed the pre-flight procedures and meteorological data. While weather at the departure and arrival airports was reported as good, the en-route weather was found to be in Instrument Meteorological Conditions (IMC). Crucially, the investigation established that the student pilot had not been briefed on this en-route weather, which was available at the local meteorology office.
Findings
- The aircraft was in a spin dive at the time of impact because the student pilot lacked the necessary proficiency in instrument flight rules (IFR) to manage the encounter with IMC.
- The pre-flight briefing provided to the student pilot was incomplete, as it omitted critical en-route weather information.
- The student pilot's training in radio and general instrument flight was introductory in nature and not intended to qualify them for IFR operations.
- The aircraft was airworthy and the engine remained operational until impact.
Safety action
Following the accident, the Indonesia Civil Aviation Institute implemented several changes, including upgrading briefing room facilities to allow for satellite weather monitoring and providing more comprehensive weather briefings to students. The institute also expanded its training syllabus, increasing the hours dedicated to both general and radio instrument flight, and introduced specific training for recovering from unusual flight positions.