What happened
On 22 December 2024, a Pilatus Britten-Norman BN2B-26 Islander, registration P2-SAM, operated by North Coast Aviation Limited, crashed into terrain approximately 32 nm northeast of Nadzab Airport in Morobe Province. The aircraft was engaged in a flight operation between Wasu and Nadzab when it struck trees and impacted a steep, heavily vegetated cliffside. The impact forces and subsequent fire destroyed the aircraft.
The investigation
The investigation examined the flight path, aircraft systems, and operational procedures. Investigators utilized V2 Track data to reconstruct the aircraft's final trajectory, which showed the plane striking a tree trunk before hitting the terrain. The inquiry also reviewed the functionality of the aircraft's Garmin 430W receiver, noting that while the unit had terrain display capabilities, it was displaying an indicative terrain failure. Additionally, the investigation looked into the operator's route guidance materials, specifically comparing the physical NCA Route Guide against the electronic flight bag (EFB) application used in the cockpit.
Findings
- The aircraft struck dense vegetation and a steep slope, which arrested its forward motion.
- The Garmin 430W receiver was not providing active color-coded terrain warnings or aural alerts at the time of the accident.
- There was potential for confusion between the paper-based NCA Route Guide and the electronic Oz Runways EFB app guide.
- The lack of functional terrain awareness alerts was a critical factor in the pilot's inability to recognize the proximity of the terrain.
Safety action
Following the investigation, the AIC issued several recommendations:
- To North Coast Aviation Limited: Ensure no confusion exists between different route guidance formats and ensure all aircraft equipped with GPS terrain warning capabilities maintain functional color-coded and aural alerts.
- To the Civil Aviation Safety Authority of Papua New Guinea: Implement requirements for operators to ensure terrain warning systems are active and serviceable, and improve oversight regarding the maintenance of pilot training and operational records.