https://arstechnica.com/tech-policy/2019/04/whistleblowers-faa-737-max-safety-inspectors-lacked-training-certification/

According to the whistleblowers cited by Wicker, some of the inspectors that had not been properly trained or certified may have been participants in the Flight Standardization Board (FSB) for the 737 MAX--a body formed by the FAA’s AEG to determine pilot-training requirements to receive “type ratings” for the 737. The FSB’s report determined that 737 type-rated pilots required no additional training to fly the 737 MAX, and no additional documentation was added to the 737 MAX’s operations manual regarding the Maneuvering Characteristics Augmentation System (MCAS).

That lack of additional training and documentation played a role in the crash of a Lion Air 737 MAX off the coast of Indonesia in October of 2018. The pilots were searching through the operating manual for procedures to disable the aircraft’s automatic stabilizer trim control software in the moments before the crash, according to investigators’ review of the cockpit voice recorder data.