According to Business Insider, the FAA received at least nine complaints from pilots about the Boeing 737 Max line of aircraft.
The new commercial airliner has been in service since 2017, but in more recent months it has come under international scrutiny after two planes crashed under similar circumstances.
Anonymous incident reports from the Federal Aviation Administration's database indicate pilots have had trouble making a descent with the 737 Max 8.
But other problems include issues with the plane's autopilot system and auto-throttling.
However, one pilot criticized Boeing for preparing an insufficient and incomplete flight manual, which lacked adequate information about an automated anti-stall system.