Independent Air Flight 1851 Crash at Santa Maria (N7231T)

Incident Overview and Clearance Error Independent Air Flight 1851, a Boeing 707, departed Bergamo, Italy, at 10:04 UTC for Punta Cana, Dominican Republic, with a planned stop at Santa Maria, Azores. At 13:56:47 UTC, Santa Maria Tower cleared the aircraft to descend to 3,000 feet for an ILS approach to runway 19. The trainee controller transmitted an incorrect QNH of 1,027 hPa, which was 9 hPa higher than the actual value of 1,018.7 hPa. This error placed the aircraft approximately 240 feet below its indicated altitude. ## Crew Response and Approach Failure The first officer began reading back the clearance before the controller finished, stating a descent to 2,000 feet. The captain agreed with this interpretation, and the crew failed to conduct an approach briefing. Had the approach plate been reviewed, the crew would have identified the minimum safe altitude of 3,000 feet and the elevation of Pico Alto. ## Final Descent and Impact At 14:06 UTC, the aircraft was 7.5 nautical miles from the impact point, leveling at 2,000 feet in light turbulence. At 14:07 UTC, it entered clouds at approximately 700 feet AGL in heavy turbulence. The captain noted difficulty maintaining level flight at 14:07:52 UTC. The radio altimeter and GPWS alarms sounded at approximately 14:08 UTC, but the crew did not react. At 14:08:12 UTC, the aircraft impacted a mountain ridge on Pico Alto at approximately 1,795 feet AMSL.