Concerns about Boeing's development of the plane "are serious enough to suggest that shareholders would benefit from the most robust form of independent board oversight, in the form of an independent board chair, " ISS said.
The company was named as a defendant in growing number of lawsuits filed by families of passengers killed off the coast of Indonesia on October 29 and also an undercover Airlines crash on March 10.
Separately, two groups that advise investors recommend that Boeing shareholders split the jobs of chairman and CEO, now both held by Dennis Muilenburg, as the company deals with two deadly crashes involving its new plane, the 737 Max.
A Flight Standardization Board, comprised of pilots who fly the 737, said in a draft report released Tuesday that it reviewed "the modified Maneuvering Characteristics Augmentation System" and concluded simulator-based training is not necessary for pilots who flew the previous version of the 737.
The report pointed out that the FAA's review panel only evaluated the training aspects related to the software fix.
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Liverpool are also aiming for glory on the domestic front, where they sit top of the Premier League and are locked in a title battle with Manchester City .
"Boeing Co.is still expected in the coming weeks to submit the final software package for certification".
The FAA held a meeting on Friday in Washington with the three US airlines that fly the 737 Max along with representatives of their pilot unions to discuss the steps needed to return the plane to service. Last month, reports showed that American Airlines was cancelling 90 flights per day through April.
"The airworthiness of the airplanes must be checked and approved again, the necessary refit for the airplane and pilot training should be effectively carried out, and safety issues revealed in the investigation results should be addressed so as to ensure 100 percent flight safety", said Xu.
Boeing's 787 Dreamliner got off to a rocky start after a battery issue that led to a temporary grounding, but the plane has gone on to become a popular aircraft in the widebody market.
The application came via the U.S. Federal Aviation Administration (FAA), which sent Boeing's applications to nine countries, according to CAAC.
The lawsuit said that Boeing should have advised investors that the security features were optional to the Max jets it sold.