The C-17 Globemaster III is a massive, four-engine jet that can haul 60-ton tanks, troops and medical gear across continents and land on short runways.

The Air Force stopped ordering C-17s in 2006. Since then, Congress added last-minute appropriations for more planes to keep the plant rolling. Again and again, lawmakers came to the program's rescue, partly because it supports roughly 30,000 supplier jobs in 44 states.

In 2010 lawmakers set aside funding for 10 new planes. That year, then-Defense Secretary Robert M. Gates told Congress he would recommend that President Obama veto legislation that contains money to pay for any additional C-17s.

There have been no new orders from the U.S. since then. Last year, the Air Force granted to Boeing a contract for $500 million calling for transition to "post-production."

As Air Force orders have dwindled, Boeing has cut jobs at the plant. The Chicago company said it slowed production rates to 10 aircraft a year from 15 to extend the assembly line's life by several months.

The slower production rates would buy time for Boeing to sell more planes to foreign buyers that came too few and far between.

For several years, the company has been pushing foreign sales to help prolong work there. But because most foreign orders were relatively small they haven't sustained the plant for more than a few months.

"While not unexpected, today's announcement closes the chapter on production of a remarkable aircraft," Long Beach Mayor Bob Foster said. "As work slowed over the last several years, we worked side by side with Boeing to extend the C-17 line for seven additional years. There's a sense of sadness to see the end of an institution."

There's some hope. Boeing, which for years has been cutting its workforce in Southern California, announced that the work performed by 375 people in the Puget Sound region around Seattle is being moved to Long Beach over the next 18 months. In May, the Chicago plane maker said 300 engineering support jobs would come to the region, as well as the establishment of a new engineering design center for commercial aircraft.

As workers filed out of the building after the 2:30 p.m. shift change Wednesday, some looked upset, shaking their heads, while others smiled and told reporters everything was all right.

Tooling engineer Ken Hubbard, who worked for 27 years at the plant, said he will be touching up his resume.

"For starters it's a wonder it lasted as long as it did," he said. "Nothing lasts forever."

william.hennigan@latimes.com

samantha.schaefer@latimes.com

Times staff writer Shan Li contributed to this report.