Indonesian crash investigators have revealed the Lion Air 737 that crashed last week killing 189 passengers had faulty speed readings on the previous four flights.
Indonesia’s National Transportation Safety Committee, with the help of the Australian Transport Safety Bureau has downloaded the previous 69 hours of flight data from the Flight Data Recorder for the planes’ last 19 trips.
However, the cockpit voice recorder remains elusive.
NTSC chief Soerjanto Tjahjono told media on Monday that “we have said there’s a technical problem but we also want to know what they were discussing in the cockpit and what they were doing”.
Lion has confirmed the technical faults recorded on the previous flight from Denpasar to Jakarta were attended to and rectified before the fatal flight.
On that flight the plane had erroneous speed and altitude data and went into a wild dive making passengers sick.
The pilot of the flight requested a return to Denpasar but the situation corrected itself and he elected to continue to Jakarta.
The focus is on the aircraft’s speed and altitude sensors made up of the Pitot Tube and Static Port which compare air pressure to give flight data.
A pitot-static system determines an aircraft’s airspeed, altitude, and altitude trend and is connected to the pilot’s instruments and the plane’s computers including the autopilot.
Investigators have also revealed that the 737 was intact when it hit the water with the engines running at high speed.
“The aircraft hit the water at high speed and it didn’t break apart mid-air,” said Tjahjono. “The engines were still running at high RPM.”
The search has been extended for three days and will almost certainly be extended again until the CVR is found.