Boeing’s new chief executive has announced plans to reduce its workforce by 10%, or about 17,000 jobs, as he seeks to restructure the company in an effort to slash costs and improve production of planes, which has been plagued by numerous delays.

Kelly Ortberg, who became CEO in August, told employees in a memo that Boeing, which last reported an annual profit in 2018, faced big problems and needed to change how it did business in ways that play to its strengths.

The announcement on Friday came as the company is dealing with a costly and disruptive strike that began nearly a month ago, when members of its largest union rejected a contract offer and walked off the job. The union, the International Association of Machinists and Aerospace Workers, represents more than 33,000 Boeing employees.

Boeing on Friday also reported $5 billion in new costs associated with several commercial and defense programs.

“Our business is in a difficult position, and it is hard to overstate the challenges we face together,” Ortberg said. “Beyond navigating our current environment, restoring our company requires tough decisions and we will have to make structural changes to ensure we can stay competitive and deliver for our customers over the long term.”

The cuts, which will include layoffs and not refilling positions as employees leave, amount to a 10% reduction of Boeing’s 170,000 employees. Ortberg said the cuts will be implemented across the company, affecting executives, managers and production workers.

Boeing announced a similarly large job cut in April 2020, when air travel fell about 90% as the coronavirus pandemic took hold. At the end of that year, Boeing employed 141,000.

Ortberg, a former top executive at Rockwell Collins, a major aerospace supplier, said Boeing would also change its product lineup and adjust its schedule for selling new jets. It will do away with the 767 freighter, an older model, after fulfilling outstanding orders. He also confirmed that the company would deliver its first 777X, a large plane designed for international travel that has been delayed repeatedly, in 2026, a year later than had previously been expected. When Boeing started the 777X program, in 2013, it slated the first delivery for 2020.

Ortberg also said that he expected additional losses from a handful of already-costly defense products that Boeing had agreed to build at a fixed price.

Ortberg’s appointment was part of a management shake-up in response to a crisis that began when a door panel blew off a Boeing 737 Max 9 during an Alaska Airlines flight in January. That episode renewed concerns about the quality and safety of Boeing’s planes several years after two fatal crashes involving the smaller Max 8 version.

In response, the Federal Aviation Administration limited production of all Max planes until it was convinced that the company had made sufficient quality improvements. Boeing has changed practices and increased training and oversight.