Federal Aviation Administration

It would be “reckless” to “lower the safety of the flying public” and would lead to “ever increasing air disaster”

-Aviation unions in response to FAA giving airplane manufacturers more freedom in determining their planes' safety

Boeing 737 Max 8

MCAS

There were 2 versions of MCAS. The first version would only engage in rare situations at high speed and gave pilots a 3 second reaction time. It relied on two types of sensors, G-force and AOA sensors, as well as only moved the horizontal stabilizer 0.6 degrees in 20 seconds. The FAA's internal review gave it a hazardous rating and required it to have 2 levels of redundancy, but justified not telling pilots about the system.

However, a new version of MCAS was pushed without FAA approval. It engaged more frequently at low-speed situations while also quadrupling its effect (2.5 degrees almost immediately). It had 3 requirements to trigger: flaps up, autopilot off, and one AOA sensor showing stall.

"The change to MCAS didn’t trigger an additional safety assessment because it did not affect the most critical phase of flight, considered to be higher cruise speeds. "

Mark Forkner - Chief Technical Pilot for Boeing

Mark was the primary liaison with the FAA, having worked there for a long time. He didn't fully understand the software and was pressured by company management to approve everything quickly.

Conclusion

• FAA made the conscious decision to leave MCAS out of the pilot's manual

  • The channeling went through Forkner who had a prior relationship with the FAA

  • This was in large part due to the fact that many were not aware of what the revamped MCAS actually did

• The whole process is evidence of significant miscommunication in the agency

  • Some parts of the agency knew about the revamp, others did not

• The trust in Boeing was significant

  • The FAA lacks expertise and resources so much of their work was delegated to Boeing