823
2011-SEP-29 · Mount Leuser National Park, North Sumatra, Indonesia

Nusantara Buana Air — Flight 823

Nusantara Buana Air Flight 823 crashed into a 70 degree slope in the Mount Leuser National Park after the crew elected to continue a Visual Flight Rules (VFR) flight into instrument meteorological conditions. The aircraft impacted terrain at 5,055 feet altitude while the pilots were flying in cloud, resulting in the deaths of all 18 people on board. Investigators determined the crew lost situational awareness and visual reference to the ground, failing to take any recovery action before the impact.

Aircraft
CASA C-212-200 Aviocar
Registration
PK-TLF
Phase
Cause
Souls on Board
18
Fatalities
18
Origin → Dest
Polonia International Airport, Medan, Indonesia → Alas Leuser Airport, Kutacane, Indonesia
Report

Investigation Summary

The flight was a non-scheduled passenger service operating under Visual Flight Rules (VFR). Shortly after departure from Medan, the crew requested a direct route to a waypoint named PAPA and climbed to 8,000 feet. Despite the VFR requirement to remain clear of clouds, Cockpit Voice Recorder (CVR) analysis revealed that both pilots agreed to enter cloud cover. This decision led to a total loss of visual references. The investigation highlighted a steep cockpit transition gradient, where the First Officer, a former Indonesian Army pilot, did not effectively challenge the Captain's decisions. Furthermore, the crew failed to perform standard checklist readings or a pre-flight briefing. The aircraft was equipped with an Emergency Locator Transmitter (ELT) which successfully triggered, allowing search teams to locate the wreckage the following day. The Indonesian government briefly suspended the airline's Air Operator Certificate (AOC) following the accident, grounding the fleet while safety measures were reviewed.

Final Conclusions

The National Transportation Safety Committee (NTSC) concluded the accident was a Controlled Flight Into Terrain (CFIT). The primary cause was the crew's decision to continue flying into weather conditions below VFR minima, leading to a loss of situational awareness. Contributing factors included a lack of crew coordination due to a steep cockpit transition gradient and the omission of required checklists and briefings. The NTSC also noted that the crew had not received specific CFIT or Approach and Landing Accident Reduction (ALAR) training.

Video Analysis

No video analysis linked for this case file yet.

Airframe & Maintenance

Airframe Hours
11,348
Cycles
13,646
Engines
Garrett TPE331-10R-521C

Crew Experience

Captain

Total hours
5,935
On type
3,730

First Officer

Total hours
2,500
On type
1,100

Former Indonesian Army pilot.

Systems & Failure Modes

i

Emergency Locator Transmitter (ELT)

A device designed to transmit a distress signal upon impact; the unit on PK-TLF functioned correctly, allowing rescuers to find the site.

i

Cockpit Voice Recorder (CVR)

A flight recorder used to record the audio environment in the flight deck; analysis confirmed the pilots agreed to fly into clouds.

Interesting Facts

  • 01The aircraft was a CASA C-212-200 Aviocar manufactured in 1989.
  • 02The flight was conducted under Visual Flight Rules (VFR) but entered clouds.
  • 03The wreckage was found 16 nautical miles from the destination airport, Kutacane.
  • 04All 18 occupants, including two children and two infants, were killed in the impact.
  • 05The Captain had 3,730 hours of experience on the CASA C-212 type.

Safety Actions & Advisories

AOC Suspension

The Indonesian Government suspended Nusantara Buana Air's air operator's certificate immediately following the crash, grounding the fleet.

Training Mandates

The NTSC recommended the Indonesian Directorate General Civil Aviation improve supervision and ensure pilots receive CFIT and ALAR training.

Location

Mount Leuser National Park, North Sumatra, Indonesia · 3.4000, 98.0167

Related Cases

Case ID · nba823-2011Last updated · Filed

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