(AP) — Aircraft parts maker Spirit Aerosystems plans to cut more jobs at its plant in Wichita, starting in September.

Thursday’s announcement came roughly a month after Spirit said it was laying off about 360 salaried support and management workers at its facilities in Kansas and Oklahoma.

Spirit says in a statement that the number of upcoming cuts in Wichita hasn’t been finalized. The company says it will start by offering voluntary retirement and voluntary layoff programs, followed by layoffs of management and salaried employees.

Spirit has about 11,000 employees in Wichita and 2,500 at its plant in Tulsa, making large airplane components for such manufacturers as Boeing and Airbus.

The company says its remains strong, with a “robust backlog” of orders worth about $38 billion.