For more than four decades, manufacturing was the only work Donetta Raymond knew.
Fresh from high school, she followed her father to the factory floor because, she said, "It was the best-paying job around."
Starting as a sheet metal mechanic, Ms. Raymond found plenty of work in her hometown, Wichita, Kan., home to famous names in aviation like Cessna, Beech and Boeing.
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She applied her skills, eventually becoming a production operation specialist on 737 airplane fuselages at Boeing's sprawling facilities. Her work was praised consistently, including a good performance review in 2012 from the management of Spirit AeroSystems Holdings.
The next year, she underwent a separate company review to gauge whether the company should retain her. Ominously, she slid to a "C" from her "A" rating the previous year.
And just a few months later, the company laid off hundreds of longtime workers, including her, then aged 59. The layoffs were swift and blunt.
"They walked us out, and wouldn't let us go back and say goodbye," said a fellow worker, Debra Hatcher, 57, then a manufacturing operations analyst. "They drove us to an empty parking lot, and that was it."
Spirit AeroSystems — formed from Boeing's 2005 sale of its Wichita division and Oklahoma operations — is an important supplier for Boeing, its biggest customer, and a rival, Airbus, chalking up nearly $1.7 billion in revenue in the first quarter of this year.
When it laid off 360 workers in summer 2013, the company was not closing down or moving jobs to Mexico or anywhere else. Spirit, which has 11,000 employees in Wichita and operations in Europe and Asia, said layoffs among its salaried employees and managers were necessary to remain competitive.
Today, a lawsuit filed by 70 former employees, including Ms. Raymond, is in proceedings in the Federal District Court in Wichita. The lawsuit was cleared first by the federal Equal Employment Opportunity Commission, which must decide the validity of any claim of age or disability discrimination before it can proceed.
The workers brought the suit after discovering that nearly half — or 164 — of those in the 2013 layoffs were 40 or older, the age that initiates federal age discrimination law protections. And workers charge that they were singled out, in addition, because either they or their spouses had serious medical conditions.
Sprit maintains that it does not discriminate in hiring or termination decisions.
"Reductions in force are never easy, however all decisions are based on job-related, nondiscriminatory criteria," said Fred Malley, Spirit's spokesman.
"We are confident the evidence in this case will show Spirit is compliant with the law in its employment practices."
Such lawsuits are popping up as the nation's work force ages and as many longtime workers claim that they are being deliberately targeted for such reductions. As manufacturing has contracted, more experienced workers feel they have limited options for re-employment if they are discarded at older ages.
"Once layoffs were done by reverse seniority. It was last in, first out, so the more senior workers kept their jobs," said Robert J. Gordon, an economics professor at Northwestern University, who studies the country's growth and work force productivity.
"Now we're seeing a transition from the age of favoritism to that of age discrimination," Mr. Gordon said, "because newer workers are allowed to stay on while more costly, older workers are let go."
One of the few recourses for employees is to file a job discrimination complaint with the Equal Employment Opportunity Commission. Nearly 21,000 age discrimination complaints were filed in 2016 with the commission, up from 20,144 in 2015, though down slightly from a high of almost 25,000 in 2009 during the financial crisis, when huge numbers of jobs were eliminated.
In recent years, the number of filings has hovered in the 21,000 range, and age discrimination accounts for nearly a quarter of the overall complaints filed with the agency, which also pursues charges of discrimination against a job applicant or employee on the basis of a person's race, color, religion, sex, national origin, disability or genetic information.
Yet, even as the work force has a large number of older employees, one of the principal tools to fight such discrimination, the Age Discrimination in Employment Act — which Congress passed a half-century ago — may not be up to the task, said Laurie A. McCann, a lawyer with AARP Foundation Litigation, which is providing legal counsel to the Wichita plaintiffs.
"Ageism unfortunately remains pervasive in the American work force," she said. Only two of the cases the E.E.O.C. filed in court last year involved the federal age discrimination act, according to a list assembled by AARP, the nonprofit older citizens group.
They were among a total of only 86 workplace discrimination cases litigated in court last year, AARP found. Few cases are taken to court because such complaints are complicated and expensive; it can take a long time to assemble relevant evidence and testimony.
And a 2009 Supreme Court ruling has made proving age discrimination more difficult legally. In a case brought by the insurance executive Jack Gross, who was among a dozen employees who were demoted, the court overturned an initial favorable ruling him and imposed a tougher legal standard.
To win, the court said, plaintiffs like Mr. Gross had to prove that age discrimination was the prime, or motivating, reason for demotion or dismissal.
Without action by Congress to shore up the 1967 law, employers seem likely to continue to have an edge. In February, a group of senators, including Robert P. Casey, Democrat of Pennsylvania, and Susan Collins, Republican of Maine, introduced the Protecting Older Workers Against Discrimination Act. But past efforts to strengthen older worker rights have foundered on opposition from business groups, and the current bill is given little chance of passage.
And many discrimination cases never reach the courtroom because they are settled voluntarily, said Victoria A. Lipnic, acting chairwoman of the Equal Employment Opportunity Commission, which in 2016 recovered just under $350 million for discrimination victims through mediation, conciliation and settlements. That compared with $52.2 million recovered from cases that involve litigation, she said in an interview.
People who work in states like California and New Jersey, which have strong anti-discrimination laws, may fare better complaining to state employment fairness agencies than relying on federal agencies or courts.
Still, proving age bias is difficult. Even companies that decide that older workers are too expensive, with their larger paychecks and costlier health insurance, rarely detail this in internal documents or emails. And court rulings have given companies significant leeway to defend against such lawsuits.
"Employers have a great deal of freedom to decide how layoffs occur," said Lisa Klerman, a law professor at the University of Southern California Gould School of Law, and a mediator in employment disputes.
While long-term workers are better off than they were a half-century ago when employers flatly blocked applicants over 55 years old and ran help-wanted ads that said "only workers under 35 need apply," older employees still can encounter different kinds of age bias.
Age-related harassment complaints, especially remarks that belittle or demean longtime workers' skills or contributions, are up noticeably. They rose to 4,185 last year, an increase of almost 14 percent since 2011, according to E.E.O.C. data.
But under the law, comments that perpetuate stereotypes — like "older workers are deadwood" — do not carry a stigma equal to that of similar remarks on race or sex. While such demeaning remarks are not seen as conclusive proof of bias, they can help persuade a fact-finder, mediator or court that some wrongdoing has occurred in a workplace.
"Those remarks can plant seeds in the mind of fact-finders about a company's motivations," Ms. Klerman noted. Mediators or judges can look at a list of criteria, including safety records, attendance, leadership, communication and interpersonal skills, that the company lists as factors it uses to evaluate workers, she said.
"Of course, many of those are subjective," she acknowledged.
In Wichita, dozens of laid-off Spirit employees who are challenging their layoffs say their situation was exacerbated by the company's use of personal medical information to single them out for layoffs. A short time before the dismissals, they said in legal papers, Spirit switched to self-paid medical insurance, giving it an incentive to jettison higher-risk or sick employees to save money, they say.
Then a few months after the 2013 layoffs, Spirit held a job fair to recruit for empty jobs, some of which appeared to have the same or very similar duties to the positions that had been vacated.
But, according to Ms. Raymond and others, the company, Wichita's largest employer, with few exceptions, would not accept résumés, interview or rehire the discharged workers. Since those layoffs four years ago, aircraft parts plants in Wichita are now scrambling to find enough workers to fill a resurgence in orders.
But that is little consolation to Ms. Raymond, who last October was told she had ovarian cancer. To get by, she said she had drawn down her savings, started her Social Security benefits earlier than planned and underwent retraining to use power tools to make cabinets. She was further squeezed financially because she did not take the company's severance pay package and waived further claims against it.
"It hurt big time not to do that," she said, "But I think it was unethical and illegal to use our health conditions and age against us, and I want to see that through and make sure everyone knows the company did that."
Ms. Hatcher, her colleague, who has struggled to make a living with jobs in real estate and in estate sales, declined the severance payment as well. The women and their former colleagues say it's a matter of principle.
"It's infuriating that you spend so much time with a company, and give them your loyalty and it winds up this way," Ms. Hatcher said. "It's just discrimination."