WASHINGTON/SEATTLE—The head of the Federal Aviation Administration who oversaw the return of the Boeing 737 MAX after two crashes grounded the plane, and the agency’s zero tolerance toward unruly passengers, will resign on March 31, the agency said on Wednesday. FAA Administrator Steve Dickson, who took over in August 2019, has faced criticism over the standoff between aviation and telecommunications industries over the deployment of the 5G wireless spectrum. Dickson, 64, a former Delta Air Lines executive and pilot, was appointed by former president Donald Trump and is about half-way through his five-term as the head of the 45,000-employee agency that oversees U.S. airspace. In late 2020, Dickson personally flew the 737 MAX after requiring Boeing to make training and software improvements before he allowed it to return to operations and has repeatedly said Boeing must do more to improve. He has also taken a tough line with Boeing on …