The FAA said the Boeing 737 Max had a high risk of crashing, but let the plane continue flying anyway

Reuters

An internal FAA analysis after the first Boeing 737 Max crash found a high likelihood of future crashes. However, regulators decided to let the plane continue flying.

The November, 2018 internal review was discussed by the House Rep. Peter DeFazio during a transportation committee hearing on Wednesday. The news was first reported by The Wall Street Journal.

The analysis reportedly found that without design changes, a 737 Max plane could be expected to crash every two to three years, The Journal reported. That was a substantially greater risk than Boeing or the FAA had indicated publicly.

FAA 737 Max AnalysisHouse Committee on Transportation & InfrastructureThe analysis by the FAA found that without interventions, there could be 15 more crashes over the life of the 737 Max, attributable to the plane’s design.

The assessment raises additional questions about how the 737 Max was initially certified, and allowed to continue flying after the first crash, Lion Air Flight 610 in Indonesia. Less than five months later,Ethiopian Airlines Flight 302 crashed.

“I don’t know why this aeroplane wasn’t grounded after the analysis was done,” Rep. Peter DeFazio said.

The FAA issued an emergency Airworthiness Directive about runaway trim stabilisation control on the 737 Max after the first crash, but it did not discuss the automated system behind the crashes, known as the Manoeuvring Characteristics Augmentation System (MCAS), or highlight the FAA’s risk assessment.

The FAA projected as many as 15 similar catastrophic incidents globally over the life of the global 737 Max fleet, Rep. DeFazio said, unless fixes including the software changes Boeing has reportedly made, were implemented.

“Over a 45 year period, we’d have an unacceptible level of risk,” FAA administrator Steve Dickson said. “So we’d have to take action to reduce that risk.”

Boeing began working on a fix for the faulty MCAS software following the first crash, but the plane continued flying in the interim.

A Wall Street Journal analysis of the FAA report characterised the Max, without fixes, as more accident-prone than other Boeing models.

In a statement provided to Business Insider, Boeing said that the FAA’s established response guidelines to the analysis findings suggested that the plane should be able to continue flying in the interim:

The TARAM (Transport Aeroplane Risk Assessment Methodology) analysis provides guidance on the appropriate timeline for implementing mitigating actions for potential safety issues. Based on such an analysis, an FAA Corrective Action Review Board-the FAA’s established process for evaluating safety issues-determined that Boeing’s and the FAA’s actions in early November to reinforce existing pilot procedures through issuance of an Operations Manual Bulletin and Airworthiness Directive sufficed to allow continued operation of the MAX fleet until changes to the MCAS software could be implemented. Boeing’s own TARAM analysis was consistent with the FAA’s conclusions. The actions that Boeing and the FAA took, including the issuance of the Operations Manual Bulletin and Airworthiness Directive and the timeline for implementing the MCAS enhancements, were fully consistent with the FAA’s analysis and established process.

The 737 Max, the latest version of Boeing’s best-selling plane, has been grounded since March after crashes in Indonesia and Ethiopia killed 346 people.

Investigations into the two crashes suggest that MCAS erroneously engaged, forcing the planes’ noses to point down, and that pilots were unable to regain control of the aircraft.

The system could be activated by a single sensor reading. In both crashes, the sensors are thought to have failed, sending erroneous data to the flight computer and, without a redundant check in place, triggering the automated intervention.

MCAS was designed to compensate for the 737 Max having larger engines than previous 737 generations. The larger engines could cause the plane’s nose to tip upward, leading to a stall. In that situation, the system could automatically point the nose down to negate the effect of the engine size.

Since the grounding, other potential safety issues have been found in the plane, leading Boeing to make major changes to how its onboard flight computer functions.

Do you work for Boeing, or one of the airlines affected by the Boeing 737 Max grounding? Contact this reporter at [email protected].

Business Insider Emails & Alerts

Site highlights each day to your inbox.

Follow Business Insider Australia on Facebook, Twitter, LinkedIn, and Instagram.