The inquiry into the plane crash in Tehran comes as the jet’s manufacturer, Boeing, is facing even more scrutiny over its troubled 737 MAX jet, as released internal emails show Boeing employees talking about deceiving federal regulators and joking about potential safety flaws in the plane’s design ahead of the two fatal plane crashes that killed all 346 people on board in Ethiopia and Indonesia. In one email, an employee wrote, “This airplane is designed by clowns, who are in turn supervised by monkeys.” In another, an employee asked a colleague, “Would you put your family on a Max simulator trained aircraft? I wouldn’t.” In a third, an employee wrote, in apparent reference to interactions with the Federal Aviation Administration, “I still haven’t been forgiven by God for the covering up I did last year.” The Boeing 737 MAX has been grounded worldwide.