Boeing reached a new contract on Friday with about 1,600 white-collar workers with the former Spirit AeroSystems, which it re-acquired in December.

The contract, which expires in late 2030, was approved with 85% of votes cast.

The contract includes a $6,000 ratification bonus, annual wage increases, improvements to medical and retirement plans, and an additional six days off a year.

It was the first labour deal reached with former Spirit AeroSystems employees.

The workers are part of the Society of Professional Engineering Employees in Aerospace's (SPEEA) Wichita Technical and Professional Unit. SPEEA represents 11% of Boeing's 182,000 employees, according to recent company filings with the US Securities and Exchange Commission.

Boeing will start negotiations later this year with SPEEA's two largest bargaining units, which comprise roughly 16,000 engineers and technical workers in Washington, Oregon, California and Utah.