In April, Boeing provided a $425 million advance to support Spirit's liquidity. Spirit, Wichita's largest employer with around 12,800 full-time workers, previously disclosed it has spent all of that money, as well as the entirety of a $350 million bridge loan that was set up earlier this year.

The airframe manufacturer will get a new cash infusion from its major customer to ensure it can remain financially stable and maintain inventory, reduce operating expenses,

According to Reuters, Boeing and Spirit AeroSystems are close to reaching a funding agreement to give the struggling supplier a cash lifeline. The funding will increase the company's liquidity, which it needs to continue operating for the foreseeable future.