Indonesian authorities said the plane deviated from its flight path after the two pilots fell asleep

CNN
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Indonesia's Ministry of Transport will launch an investigation after two Batik Air pilots fell asleep during a recent flight, according to state news agency Antara, citing the ministry's director-general of civil aviation, M. Christi Indah Murni.

According to a preliminary report released on Saturday by the National Transportation Safety Board (KNKT), the pilot and co-pilot fell asleep simultaneously for 28 minutes during a flight from Kendari in Southeast Sulawesi province to the capital, Jakarta, on January 25, causing navigational errors. Because “the plane was not on the correct flight path.”

No one on board — including 153 passengers and four flight attendants — was injured during the flight, and no damage was done to the plane, KNKT's initial report said.

The flight, BTK6723, took two hours and 35 minutes and landed successfully in Jakarta, according to Antara and the initial report.

CNN has reached out to Batik Air.

According to the report, the second-in-command pilot told his co-pilot earlier in the day that he was not getting “proper rest.”

On the flight before the accident, the second man was able to sleep for “about 30 minutes.” After the plane left Kendari and reached cruising altitude, the pilot also requested permission to rest and the second man took control of the plane. About 90 minutes into the flight, the second-in-command “unintentionally fell asleep,” according to the report.

She added that 12 minutes after the last recorded transmission by the co-pilot, the Jakarta area control center tried to reach the plane, but there was no response from the pilots. About 28 minutes after the last recorded transmission, the pilot woke up and realized that the plane was not on the correct flight path. At that point, the second-in-command was awakened and responded to the ACC, she added.

The initial report stated that the plane's pilot told the ACC that the flight had encountered a “radio communication problem” and had been resolved.

The report did not reveal the names of the pilots, but it identified the plane's pilot as a 32-year-old Indonesian man and the second in command as a 28-year-old Indonesian man. The second-in-command had 1-month-old twins and “had to get up several times to help his wife with the children,” the report said.

“We will conduct an investigation and review of the night flight operation in Indonesia regarding fatigue risk management for Batik Air and other flight operators,” Morni said in a statement, according to Antara.

The crew of flight BTK6723 have also been grounded in accordance with standard operating procedures pending further investigation, it added.

It also said the agency would send a designated Resolved Safety Issue Inspector (RSI) to investigate the cause of the accident and recommend mitigation measures to aviation operators and supervisors, Antara said.