Lion in the Sky: The Lion Air Disaster

The recent Lion Air plane disaster that killed 189 people has left the world shocked. How could a brand new airplane once again crash only a few minutes after taking off?

On 29 October 2018, Lion Air flight JT 610, a domestic Indonesian flight en route from Jakarta to Pangkal Pinang, Indonesia, crashed into the Java Sea just off the coast of Java. The incident killed 189 people, every person on board. It only crashed after 13 minutes of being in flight. Once again, it is another incident, following the Aeromexico crash in July, where an aircraft has crashed so soon after taking off.

Investigations are underway as to the cause of the incident. The aircraft was brand new, being the Boeing 737 Max 8 model which we discussed in a previous post. That post announced that Malindo Air, a Malaysian subsidiary of the Lion Air Group, was the first airline to receive the brand new Max 8. We also noted that test flights had been suspended on the 737 Max 8 after aircraft engine manufacturer CFM International informed Boeing that the plane’s Leap-1B engines could have a manufacturing error.

Nevertheless, with regards to Flight JT 610, some Australian engineers suggested there had been problems with the rear elevator. This is a significant part of the aircraft’s flight control system.

Aircraft debris and personal belongings were found littered across the Java Sea and, sadly, the police recovered dozens of body parts to test for DNA.

The flight the day before the Lion Air disaster

The Max also had control problems relating to high speed on a flight the day before. This may be relevant given the crash that occurred on 29 October happened at extremely high speeds up to 560 kilometres per hour. A technical log obtained from that previous flight indicated that the airspeed reading on the captain’s instrument was not reliable. The altitude readings were different on the instruments of the captain and first officer.

The plane had reportedly been delayed on the previous Sunday flight. It was apparently delayed by one hour. Passengers sat in the cabin without air conditioning for half an hour listening to an unusually sounding engine roar. Children were also vomiting, and people were demanding to be let off the plane.

The data for both of the flights might indicate something wrong with the pitot-static systems. These systems are pressure-sensitive instruments that feed airspeed and altitude information to an avionics computer.

Boeing 737 Max 8 inspections

Following the Lion Air disaster, Indonesian authorities have announced that all Boeing 737 Max 8 planes will be inspected. Boeing experts are to arrive in Jakarta to assess the cause of the crash. We know that the pilot requested clearance to return to the airport about 3 minutes after take-off. This indicated some problem, but the cause is still not certain.

The planes will not be grounded.

“We have many questions for them. This was a new plane,” Lion Air director stated to media. Boeing has said it is “ready to provide technical assistance to the accident investigation”.

In our previous post, we quoted George Ferguson from Bloomberg Intelligence who commented that Max family of aircraft is critical for Boeing’s revenue, saying “it is the cash generator and they can’t screw it up”. Boeing therefore hope that this is not an inherent problem with the 737 Max 8 model.

Photo created by Flickr user and used under a Creative Commons licence.