October 31, 1995, at 2050 central daylight time, a Cessna 208B, Mexican registration XASVM, was destroyed upon impact with terrain while on approach to the Piedras Negras Regional Airport, near Piedras Negras, Coahila, Mexico. The airline transport rated pilot and 8 of the passengers were fatally injured, while 2 of his passengers escaped with serious injuries.
The airplane, owned by Western Aircraft Maintenance, of Boise, Idaho, and operated by Transportes Aereos de Coahila S.A., of Saltillo, Coahila, Mexico, was operated as a scheduled commuter airline under Mexico's equivalent of Title 14 CFR Part 135. The flight originated in Saltillo, Mexico, at 1843.
Instrument meteorological conditions prevailed throughout the area for the scheduled commuter flight for which an IFR flight plan was filed. According to the operator, the pilot filed an IFR flight plan for a 1910 departure, requesting 16,000 feet MSL, via direct Monterrey, direct Coahila, with an estimated time en route of one hour and 20 minutes. The pilot estimated in his flight plan a fuel endurance of 4 hours. While 80 miles from the destination airport, the pilot contacted the tower at the Piedras Negras Airport, and was informed that the airport was closed due to inclement weather, which was reported as sky obscured, visibility zero, with fog and drizzle.
The airport was served with an NDB. No published approach are available for the airport; however, several local pilots confirmed that a local non-approved instrument procedure had been devised by local pilots. A handwritten approach chart for the NDB approach was found by the Mexican authorities in the cockpit area of the wreckage. Ground scars found near the initial point of impact are consistent with the previously reported NDB procedure for the airplane. The flaps were found extended to the approach configuration.