CHICAGO — Boeing has reopened factories in Pennsylvania, Washington and Ohio, as executives attempt to stave off further economic damage while also protecting the health of employees. The company closed its largest factories in early April, putting a halt to all final assembly of commercial aircraft. Now, after a few short weeks of deep-cleaning, Boeing executives say it is safe to return to work in a limited capacity.

Boeing has reopened its military helicopter production facility outside Philadelphia, factories in the Puget Sound region of Washington state, and a smaller military aircraft repair facility in Heath, OH. In news releases and letters to employees, the company’s leadership emphasized the economic necessity of returning to work at a time of historic vulnerability for Boeing’s business.

Boeing says a series of safety measures should be enough to prevent another spike in cases. The company’s global workforce has already experienced at least 100 coronavirus infections and at least one death.

“This phased approach ensures we have a reliable supply base, our personal protective equipment is readily available and we have all of the necessary safety measures in place to resume essential work for our customers,” wrote Stan Deal, president and chief executive of Boeing’s commercial airplanes division.

According to newly installed CEO Dave Calhoun, the company is “in uncharted waters,” and is attempting to rally employees for what promises to be a bumpy, uncertain recovery. “The impact of this global virus will change our business for years to come,” Calhoun wrote in a letter to the company’s staff. “But we’re doing what it takes to emerge from it strong and competitive.”

Boeing plants are reopening in states that are yet to meaningfully loosen restrictions. The governors of Washington state and Pennsylvania have both established stay-at-home orders that extend at least through the end of April.