What happened
On 2 November 2010, a Boeing 737-400, registration PK-LIQ, was operating flight JT 712 from Jakarta's Soekarno Hatta International Airport to Supadio Airport in Pontianak. The flight crew was aware of recurring technical issues involving the thrust reversers and the automatic deployment of speed brakes that had persisted for several months. During taxiing, the crew also noted intermittent yaw damper warnings.
During the approach to runway 15, the aircraft failed to follow the glide path automatically after capturing the localizer. The pilot flying disengaged the autopilot and autothrottle to manually correct the descent. During this phase, a discrepancy was noted where the flap lever was set to 40°, but the indicator showed only 30°. Although the flaps were eventually moved to the full position at approximately 600 feet, the aircraft's approach remained unstable.
The aircraft touched down beyond the designated touchdown zone. Upon landing, the crew encountered difficulty engaging the thrust reversers, and the speed brakes failed to deploy automatically. Due to the lack of effective deceleration, the pilot applied maximum manual braking and manually deployed the speed brake handle. The aircraft eventually came to a stop approximately 70 meters from the runway end, just 10 meters from the stop-way. There were 0 fatalities and 0 injuries among the 175 people on board.
Findings
- Maintenance procedures for addressing the thrust reverser and speed brake issues may not have been fully compliant with the Aircraft Maintenance Manual, leaving underlying symptoms unresolved.
- The crew continued an unstable approach from 1,000 feet to 50 feet, driven by a failure to accurately assess the flight state.
- Delayed deployment of the speed brakes and thrust reversers prevented sufficient deceleration, causing the aircraft to exceed the available landing distance.