Incident
The aircraft, a Martinair DC-8 registered as PH-MBH, was operating a charter flight on behalf of Garuda Indonesian Airways. The flight was carrying 182 Indonesian pilgrims from Surabaya to Jeddah with an intermediate stop at Colombo-Bandaranaike Airport. The crew consisted of nine members, seven Dutch citizens and two Indonesians.
During descent to Colombo at night in marginal weather, air traffic control cleared the crew to descend to 5,000 feet and then to 2,000 feet for landing on runway 04. In poor visibility, the aircraft struck the slope of Mount Anjimalai, approximately 85 kilometers southeast of Bandaranaike Airport near Maskeliya. The wreckage was found hours later in a remote area. The aircraft was destroyed and all 191 occupants were killed.
Investigation
The investigation determined the probable cause was a collision with rising terrain because the crew descended below a safe altitude due to an incorrect identification of their position relative to the airport. The investigation opined that this resulted from dependence on the Doppler and Weather Radar Systems on board PH-MBH, which were off-standard and allowed for misinterpretation.
Several contributing findings were reported:
- The captain lacked recent experience on the route.
- No proper route check had been conducted before permitting the captain to fly the route, violating certain provisions of Annex 6 Chapter 9 Section 4 of the Convention on International Civil Aviation.
- The copilot had little experience on the aircraft type and no experience on the specific aircraft (PH-MPH) or the route.
- The Doppler computer system was not standard for the Martinair DC-8 fleet, leaving room for misinterpretation of the distance-to-go display.
- The weather radar system was also non-standard, with no instructions in the aircraft operations manual, allowing misinterpretation of range markings.
- Evidence indicated the crew relied heavily on the Doppler system for distance-to-go information.
- Martinair had shortcomings in maintaining technical records for the aircraft and cockpit personnel route qualifications.
- Officers organizing the flight in Surabaya displayed negligence by failing to retain copies of maintenance records and navigational documentation relevant to the flight.
- The crew was unaware of correct reporting points in the Colombo Flight Information Region.
- No major pre-crash failure or pre-crash fire was found.