Sensor / Instrument Failure
The aircraft told the crew something untrue: blocked pitot tubes, a failed angle-of-attack vane, or disagreeing airspeed and altitude indications.
Modern flight decks and flight-control computers act on sensor data. When a sensor lies, both the automation and the crew can be misled in the same direction, and the failure presents as a confusing cascade of warnings rather than a clear fault message.
These investigations examine the sensor hardware, the voting logic that was supposed to reject a bad input, and the unreliable-airspeed procedures and training the crew had to fall back on.
Related terms
The aircraft departs from normal controlled flight: a stall, an upset, or a control problem the crew cannot recover from.
The crash-protected recorder that captures aircraft parameters (attitude, speeds, control positions, systems states) for at least the last 25 hours.
A component or system failed in service. The investigation asks why the part failed and why the failure was not contained by design, inspection or redundancy.