Plane had fault in vital airspeed sensor before crash that killed 189 people

A CRUCIAL sensor that is the subject of a new Boeing safety bulletin was replaced on a Lion Air jet the day before it plunged into the sea, Indonesia’s National Transportation Safety Committee has said.

Boeing said its bulletin, sent to airlines this week, reiterates guidelines on how pilots should respond to erroneous data from an “angle of attack” sensor following the October 29 crash that killed 189 people. The sensor helps to prevent the plane from stalling and diving.

Soerjanto Tjahjono, chairman of the transport safety committee, said that airspeed indicator malfunctions on the jet’s last four flights, revealed by analysis of the flight data recorder, were connected to the sensor problem.

Lion Air’s first two attempts to address the airspeed indicator problem did not work and were replaced, he said.

On a flight, from Bali to Jakarta, the two sensors disagreed.

The plane went into a sudden dive minutes after take-off, which the pilots were able to recover from. Indonesian investigators said they would provide recommendations to Boeing for distribution to airlines around the world about how to deal with a similar situation.

But Boeing said in a statement yesterday that it was directing airlines to “existing” flight crew procedures to address angle of attack sensor problems.

Boeing said it is continuing to work with the investigation.

Indonesia’s search and rescue agency has extended the search effort for the crashed plane.