Starboard engine overspeed appears to have been the triggering factor for the 9 January Comair Embraer EMB-120 Brasilia (N265CA) crash in which all 26 passengers and three crew died, according to US National Transportation Safety Board (NTSB) investigators.
The twin-turboprop, which was operating a Delta Connection flight to Detroit-Metropolitan airport from Cincinnati, Ohio, seems to have stalled and gone out of control while level at 4,000ft (1,200m). This occurred while it was executing a left turn during its approach in snowy weather.
The NTSB says that there are indications that the crew tried to shut down the starboard engine and operate the fire-extinguishing system, but that there are no signs so far either of an engine fire or of propeller-blade failure.
According to the flight-data recorder (FDR), 38s before impact the aircraft continued a left turn when the autopilot was commanding a right turn. After autopilot disconnect, the FDR indicates, the stick-shaker stall-warning activated, and within 5s the aircraft had stalled, pitched 50í nose-down and rolled 40í left. The time from the beginning of the sequence to impact was less than 40s. The NTSB says that crew exchanges on the cockpit-voice recorder have not yielded any clues.
Source: Flight International
