A report released today by the Indonesia’s National Transportation Safety Committee (KNKT), which has been seen and reported by Reuters, found a complex series of nine events led to the accident in 2018.

These include a miscalibration of the angle of attack (AOA) sensor, which forced the aircraft’s nose downwards.

Additionally, the report claims the captain did not properly brief the first officer, the aircraft should have been grounded after faults on earlier flights, and distractions in the cockpit all combined to cause the accident, which caused 189 fatalities.

Less than a year later, a Boeing 737 Max Ethiopian Airlines flight crashed and killed 157.

In light of the KNKT report, Boeing conveyed its “heartfelt condolences” to the families of victims.

“Safety is an enduring value for everyone at Boeing and the safety of the flying public, our customers, and the crews aboard our airplanes is always our top priority,” Dennis Muilenburg, Boeing president and chief executive said.

He said the company is addressing KNKT’s recommendations and are enhancing safety on the 737 Max, specifically the AOA and Manoeuvring Characteristics Augmentation System.

The aircraft model is undergoing an “unprecedented level of global regulatory oversight, testing and analysis”, Mullenburg added.

These include hundreds of simulator sessions and test flights, regulatory analysis of thousands of documents, reviews by regulators and independent experts, and extensive certification requirements.

Mullenburg said Boeing is also training crew and updating manuals.