The Federal Aviation Administration plans to fine Boeing for installing equipment on nearly 800 planes that were not approved.
In an enforcement letter to Boeing, the FAA proposes a $19.7 million fine.
The plane maker violated regulations when it installed sensors on hundreds of 737NG and 737 Max planes between June 2015 and April 2019.
Boeing allegedly installed the sensor system made by Rockwell Collins before it was tested or officially approved.
"We understand the critical importance of compliance with all documentation requirements of the FAA.’s certifications. We are committed to doing better," the company said.
Boeing still has a pending $5.4 million fine imposed in January for equipping its 737 Max and other aircraft with deficient parts.
