Now that the black box of the Lion Air Boeing 737-8 MAX that crashed on October 20, 2018, has been found, the investigation will try to determine why a months-old plane would crash into the sea minutes after takeoff. While the data is being recovered, several details surrounding PK-LQP already emerged.

The plane suffered problems the night before

Since the crash, several sources revealed that the B738 PK-LQP had faced problems on its precedent flight. According to a technical log obtained by the BBC, the plane encountered a technical problem on October 28, 2018, while carrying out flight JT43 from Denpasar (DPS) to Jakarta (CGK). The log reads “Identified that CAPT instrument was unreliable and handover control to FO. Continue NNC of Airspeed Unreliable and ALT disagree,” meaning that the airspeed and altitude readings on the captain’s instrument were erroneous, prompting him to give control to the first officer.

The information was confirmed by Lion Air spokesman Danang Mandala Prihantoro, who commented for Bloomberg, saying that the flight crew encountered an issue with the sensors used to calculate airspeed. The data recorded by flightradar24 shows that indeed, four minutes after takeoff, while it was climbing to cruise altitude, the plane acted erratically. The rest of the flight was uneventful and the plane landed safely in Jakarta. Before the final flight engineers reportedly repaired the issue and the plane was given clearance to fly, according to Lion Air Chief Executive Edward Sirait comment to local media TV1.

A brand new plane

The Boeing 737 MAX 8 MSN 43000 was on lease from Chinese CMIG Aviation Capital, an aircraft leasing company wholly owned by China Minsheng Investment Group. The plane was manufactured in 2018 and delivered on August 14. It started operating a day later. Overall, the plane had flown less than 800 hours.

It is the first major crash involving a plane of the 737 MAX family, which was introduced in May 2017.

The flight crew

Lion Air said in a statement that the pilot and co-pilot had more than 11,000 flight hours between them (6,000 for the captain, 5,000 for the co-pilot). According to Sirait, the pilots had passed mandatory drug screening. Pre-flight checks were carried out and nominal.

The airline also confirmed that one of the crew on board was a technician, as an “anticipatory measure”. It is a standard procedure for the company and was not due to the problems experienced the previous day.