What happened
On 7 March 2007, a Garuda Indonesia Boeing 737-497, registration PK-GZC, was operating a scheduled passenger flight from Jakarta to Yogyakarta. During the approach to runway 09, the flight crew performed an unstabilized descent that deviated significantly from the prescribed instrument landing system (ILS) profile.
While the crew was cleared for a visual approach, they continued with an ILS approach without notifying air traffic control. The aircraft descended steeply, causing the airspeed to climb well beyond the limits for flap extension. Consequently, the aircraft crossed the runway threshold at approximately 232 knots—nearly 100 knots faster than the required landing speed. The aircraft touched down at an excessive speed of 221 knots.
Following touchdown, the aircraft failed to stop within the runway limits. It overran the departure end of runway 09, crossed a road, and struck an embankment before coming to rest in a nearby rice paddy. The impact and a subsequent intense, fuel-fed fire destroyed the aircraft. Of the 147 people on board, 21 fatalities were recorded, including one flight attendant and 20 passengers.
The investigation
The investigation conducted by the KNKT focused on the flight crew's actions, the aircraft's flight path, and the airport's emergency response. Analysis of the Solid State Flight Data Recorder (SSFDR) revealed that the aircraft's flight path was considerably higher than the standard 3-degree glideslope. The data also showed that the Ground Proximity Warning System (GPWS) issued 15 separate alerts during the approach, which the pilot in command failed to heed.
Investigators also examined the airport's infrastructure, noting that the runway end safety area (RESA) was insufficient. Furthermore, the investigation looked into the effectiveness of the airport's rescue and fire fighting services, as well as the airline's training and oversight protocols.
Findings
- The primary cause of the accident was an unstabilized approach characterized by excessive airspeed and a steep flight path angle.
- The pilot in command failed to follow standard operating procedures by not executing a go-around despite the unstable approach and multiple GPWS warnings.
- The copilot failed to take control of the aircraft when the pilot in command disregarded critical safety warnings.
- There was a lack of specific simulator training for the crew regarding vital actions required during GPWS alerts.
- The airport's rescue and fire fighting response was hindered by the inability of certain vehicles to reach the crash site and a lack of appropriate fire suppressant agents.
Safety action
- Recommendations were made to Garuda Indonesia to improve flight operations policies and GPWS/EGPWS training.
- Recommendations were issued to the Directorate General of Civil Aviation (DGCA) to enhance regulatory oversight of airline flight operations.
- Recommendations were directed to airport operators to improve the implementation of emergency plans and the accessibility of rescue services.