American pilots who flew the Boeing 737 Max had registered complaints about the performance of the jet months before the fatal Ethiopian Airlines crash.
According to media reports, most pilots mentioned issues with the aircraft's autopilot and the plane going nose down shortly after takeoff.
One pilot reportedly wrote that the Max 8 aircraft manual was "criminally insufficient".
The US regulator, the Federal Aviation Administration, has since grounded the entire fleet after investigators uncovered new evidence at the scene of the Ethiopian crash.
From Washington, Daniel Ryntjes reports:
Pakistan bombs targets in Afghan cities, minister calls it 'open war'
IMF approves $8.1 billion loan for Ukraine
Hillary Clinton tells panel she has no information on Epstein
US, Ukraine discuss post-war reconstruction as Russia pummels grid
Israeli fire kills three people in Gaza as truce deal staggers
