Boeing

A blocked pitot tube fed false airspeed to a Boeing 757 autopilot, the crew never recovered from the stall that followed, and all 189 aboard Birgenair Flight 301 died

All 189 aboard Birgenair 301 died in 1996 when a blocked pitot tube fed the 757's autopilot a false rising airspeed and it pitched the nose steadily upward off Puerto Plata; the crew, confused by conflicting warnings, pulled thrust, raised the nose further and did not respond to the stall warning.

One letter, two beacons: American Airlines Flight 965's rushed approach ends on a mountain near Cali

American Airlines Flight 965 crashed near Cali in 1995, killing 159, after a crew entry of "R" for the Rozo beacon called up a beacon near Bogota, the autopilot turned the jet off its approach course, and the crew kept descending while trying to regain the approach without knowing where they were.

China Airlines 006: a 747 autopilot masked a developing loss of control while the captain, fixed on a failed engine, stopped watching his instruments

In 1985 a China Airlines 747SP's autopilot compensated for a failed engine until its roll authority ran out; the captain, fixed on the engine rather than his instruments, took over at 64 degrees of bank and the jet rolled inverted, falling over 30,000 feet. Two of 274 aboard were seriously hurt.