Adam Air Crash: Due to Damaged Navigation and Pilot Error
Wednesday, 26 March, 2008 | 14:36 WIB

TEMPO Interactive, Jakarta: The National Flight Safety Commission (KNKT) concluded the combination of damaged navigation system; and pilot error in operating flight instruments as the cause of the Adam Air crash on 1 January 2007, taking the lives of the pilot and co-pilot, 96 passengers, and four crew members.

According to Tatang Kurniadi, head of KNKT, the pilots' concentration on the navigation system that malfunctioned in the last 13 minutes, distracted pilots' attention from the flight instrument, allowed the increasing descent and left the bank angle unnoticed, the report stated.

“The pilots did not detect and appropriately arrest their descent soon enough to prevent loss of control,” he said in a press conference in Jakarta, yesterday.

According to the digital flight data recorder (DFDR), Adam Air flew by automatic pilot system at 30,000 feet. The plane was slowly sloping to the right with a speed of one degree per one second.

When it was over 35 degrees sloping to the right, the plane’s bank angle alert went on . When it reached 100 degrees sloping to the right, pilots could not straighten the plane back to normal. “There was no evidence that the pilots were appropriately controlling the aircraft correctly even after the bank angle alert sounded as the aircraft’s roll exceeded 35 degrees right bank,” Tatang said.

As a result there was a fatal accident. The aircraft dove with a speed of 1,100 kilometers per hour. The flight data recorder showed structural damage. The aircraft pressure changed drastically from positive 3.5g into negative 2.8g. This condition is beyond the capacity of Boeing 737. “The aircraft was unable to be controlled,” Tatang explained.

An investigator from KNKT, Mardjono Siswosuwarno, added that the plane dove fast after the pilots’ failed to bring it up. The aircraft hit the sea with a speed of over 1,000 kilometers per hour.

Adam Air Boeing 737, registered 574, departed from Djuanda airport in Surabaya early on January 1, 2007 for Manado, North Sulawesi, but the plane disappeared off the radar a few hours later while cruising at 35,000 feet. The plane's black box was found on 27 August 2007, 2,000 meters deep.

Herman Mulyadi, physician from Indonesian Air Forces (LKPA), suspects the pilots were disoriented.

“They probably did not see the earth's horizontal line in that kind of weather,” he said. The pilot was also probably stressed with the aircraft’s condition so they could not work optimally.

Adam Air Safety Director, Hartono, said that before the aircraft took off, technicians checked the plane's instruments .

The Commission pointed out that the accident resulted from a combination of factors including the failure of the pilots to adequately monitor the flight instruments, particularly during the final two minutes of the flight.

Padjar Iswara | Harun Mahbub