Spirit AeroSystems Inc. will initiate further workforce reduction next month, this time turning its focus on salaried workers and managers as it continues “an ongoing workforce assessment.” The Wichita-based manufacturer of composite structural components previously laid off more than 300 workers at three plants in Kansas and Oklahoma, and placed two plants on the sales block. Those plants employ about 3,000 workers.

The company has other plants in Nashville, Tenn. ; Prestwick, Scotland ; Preston, England ; Subang, Malaysia ; and Saint-Nazaire, France.

The problem for Spirit is cost overruns in several of the aircraft production programs it supplies, notably for Gulfstream business jets, for which it produces composite wing structures.

The company’s other products include commercial aircraft fuselages, pylons, nacelles, and wing components. In addition to Gulfstream, it supplies Bombardier’s business jet program, and it produces several products for Boeing 737 and Airbus A32 commercial jet programs.

Final numbers have not yet been determined for the salaried and management employees to be impacted in the next series of cuts, Spirit Aerosystems reported. The reductions will be accomplished through voluntary retirement and voluntary layoff programs, and to be followed by targeted reductions of management and salaried positions.

Details of the workforce reductions will be shared with eligible and included employees in the coming weeks. Spirit said it would offer a lump-sum severance payment and career transition services to employees who are laid off, and a lump=sum severance payment and healthcare bridging option to employees who are eligible for voluntary retirement.

Spirit Aerosystems said it is seeking “to balance the workforce, reduce overhead costs, increase efficiency and drive improved performance.”

The problem for Spirit is cost overruns in several of the aircraft production programs it supplies, notably for Gulfstream business jets, for which it produces composite wing structures. Spirit also supplies products to several Boeing 737 commercial jet programs, to Airbus A32 program, and to Bombardier’s business jet program.

It emphasized that it continues to manufacture its products and estimated its order backlog at $38 billion.