A Batik Air plane in Indonesia deviated from its flight path after both the pilot and the co-pilot reportedly fell asleep for nearly half an hour.

The incident, which happened in January, saw the pair in the cockpit getting some shuteye, as the aircraft drifted off it’s planned path – something that could have led to a fatal disaster for all 153 passengers on board.

It is vital for pilots to keep an aircraft on the right flight path as it is carefully mapped out by air traffic controllers to ensure the plane doesn’t cross any other aircraft’s paths.

The plane was flying from South East Sulawesi to the capital Jakarta.

It has been reported that one of the pilots had not rested adequately the night before the flight.

About half an hour after the plane took off, the captain asked permission from his second-in-command to rest for a while and he said yes.

The co-pilot took over command of the aircraft but then fell asleep himself.

A few minutes after the last recorded transmission by the co-pilot, the area control centre in Jakarta tried to contact the aircraft.

It received no answer.

Twenty-eight minutes after the last recorded transmission, the pilot woke up and realised his co-pilot was asleep and that the aircraft was not on the correct flight path.

He immediately woke his colleague up, responded to the calls from Jakarta and corrected the flight path, the report said.

The incident resulted in a series of navigation errors, but the Airbus A320’s 153 passengers and four flight attendants were unharmed during the two-hour-and-35-minute flight.

The transport ministry ‘strongly reprimands’ Batik Air over the incident, air transport director-general M. Kristi Endah Murni said, calling on airlines to pay more attention to their air crew’s rest time.

‘We will carry out an investigation and review of the night flight operation in Indonesia related with Fatigue Risk Management for Batik Air and all flight operators,’ Kristi said in a statement.

Batik Air said in a statement on Saturday that it ‘operates with adequate rest policy’ and that it was ‘committed to implement all safety recommendation’.

The pilots involved in the January 25 incident had been temporarily suspended, the statement added.

The plane landed safely after the incident.

Investigators did not identify the pilots, but said they were both Indonesians and were aged 32 and 28.

Indonesia’s transport ministry said Saturday it would open a probe into the airline.