Air Canada (AC.TO) announced on Tuesday it will pull 737 Max jets from its schedule until at least July 1 in the latest fallout from the groundings of Boeing Co's aircraft.
The new investigation into the Boeing certification was prompted by information obtained after a Lion Air 737 Max 8 crashed shortly after take-off from Jakarta, killing 181 last October.
The letter follows after the crash of two of its 737 MAX aircraft in recent months.
Boeing CEO Dennis Muilenburg sought Monday to reassure clients and passengers of the firm's commitment to safety in a video message published amid intense scrutiny following the Ethiopian Airlines Flight ET302 crash.
"Unlike France, where criminal investigations into aviation accidents seems common, it is very, very rare in the US", Hamilton added.
The system is created to bring the plan's nose down in the event the 737 is at risk of stalling - but can have catastrophic results if sensors receive erroneous information.
Since the Ethiopian Airlines crash, questions have arisen about Boeing's ties to the FAA, which has offices within the company's plants.
With 737 MAX Grounded, Airlines Face Daily Scheduling Challenges
A different crew on the same plane the night before had the same problem, but solved it after running through three checklists . Federal Aviation Administration's word that alterations to a key flight-control system will make the 737 Max safer.
A week after a Boeing 737 Max 8 passenger jet crashed in Ethiopia, that country's transport minister said recovered flight recorders from Ethiopian Airlines Flight 302 showed "clear similarities" to a deadly accident in Indonesia last October involving a Lion Air plane of the same model.
- Investigators have found strong similarities in the "angle of attack" data recorded by the Ethiopian Airlines flight cockpit recorder and data from the Lion Air jet, a person familiar with the matter said.
Boeing's main rival, Airbus, has seen its stock rise 5 percent since the crash, but can not simply pick up the slack given the complicated logistics of plane-building.
After a 10 percent drop last week that wiped almost $25 billion off its market share, Boeing stock slid about 1.8 percent on Monday.
Boeing is fully cooperating with the U.S. Federal Aviation Administration, Department of Transportation and National Transportation Safety board on all issues relating to the Lion Air and Ethiopian Airlines accidents, Muilenburg said.
There are approximately 350 Boeing 737 Max 8 aircraft in operation worldwide, belonging to 54 operators, according to the FAA.
Boeing and the FAA declined to comment on that.