What happened
On the night of July 17, 1994, a Britten Norman BN2 B, registration 8P-TAD, departed Grantley Adams Airport in Barbados, bound for Fort de France, Martinique. The flight, operated by Trans Island Air on behalf of Société Nouvelle Air Martinique, was carrying one pilot and five passengers.
During the arrival procedure under Instrument Flight Rules (IFR), the pilot requested and obtained clearance for a visual approach. While navigating the sector, the pilot reported that the Distance Measuring Equipment (DME) was not providing distance information to the airfield. At approximately 01:40 UTC, the pilot reported being at 2,70 and indicated that the terrain was in sight. However, the aircraft failed to identify the airfield or its surroundings. Shortly after, the aircraft disappeared from radio contact. The wreckage was later located in the mountains of Carbet, near Piton Lacroix, in the commune of Bellefontaine, approximately eight nautical miles from the airfield.
The investigation
The investigation focused on the aircraft's navigation systems and the pilot's ability to maintain situational awareness at night. Investigators examined the aircraft's Radio Magnetic Indicator (RMI), Horizontal Situation Indicator (HSI), and OBS instruments.
Technical analysis of the RMI revealed a significant discrepancy: while the ADF (Automatic Direction Finder) indication appeared correct, the VOR (VHF Omnidirectional Range) indication was erroneous by approximately 180 degrees. This error was attributed to a potential failure in the 26V/400 Hz power supply. Additionally, the HSI showed signs of being in ILS (Instrument Landing System) mode, with the presence of a glide slope indicator and the absence of certain navigation flags.
Findings
- The aircraft crashed into mountainous terrain while the pilot was attempting a visual approach at night.
- The pilot was unable to identify the airfield or surrounding landmarks during the descent.
- A major navigational error occurred due to a 180-degree discrepancy in the VOR indication on the RMI instrument, likely caused by a power supply failure.
- The pilot was operating with a malfunctioning DME, which prevented the continuous monitoring of distance to the station.
- The flight was conducted at night, which significantly complicated the visual identification of terrain and obstacles.