An Indonesian airliner is under investigation after two of its pilots fell asleep midflight for nearly 30 minutes while 159 passengers were on board. 

An incident report from the country’s National Transportation Safety Committee found that Batik Air flight BTK6723 diverted from its path during a Jan. 25 flight after its two pilots dozed off for 28 minutes.

The midair nap came during a two-and-a-half-hour flight from the island of South East Sulawesi to the Indonesian capital of Jakarta. 

The 32-year-old pilot in command fell asleep for an hour after notifying his 28-year-old deputy. The pilot awoke and asked his second-in-command if he would like to trade places – an offer he refused. 

The pilot awoke 28 minutes later to find that "the aircraft was not on the correct flight path" and his second-in-command was napping, according to the incident report. 

The pilot managed to get the plane back on track and land safely in Jakarta with no harm to the passengers. While they were asleep, air traffic attempted to contact BTK6723, but there was no response from the pilots. 

The pilot was not named in the incident report. It described him as a 32-year-old Indonesian national who held a valid Airline Transport Pilot License and qualified as an Airbus A320 pilot. 

Later questioned, the second-in-command said that he had been struggling to get enough sleep after helping his wife take care of their one-month-old twins at home. 

Batik Air said that both pilots have been "temporarily suspended." The country’s transport ministry said it "strongly reprimands" Batik Air over the incident. An investigation has been opened to find out what went wrong.