The Machinists union making aerospace parts at the Triumph Composite Systems factory west of Spokane rejected a labor contract Monday and voted to go on strike beginning Wednesday.

The vote by 93 percent of the 403 members of the Machinists Union Local 86 follows weeks of contract talks.

It will be the first time in nine years the union walked out on strike, said Machinists spokeswoman Connie Kelliher.

Triumph is a parts supplier for aircraft companies including Boeing and Airbus. The Machinists make floor panels and ducting systems for planes.

Union officials contended the three-year contract offer did not restore pension benefits nor did it eliminate what they called a two-tier wage system that pays some employees less than others for similar work. Also, the union is opposed to contract language that would allow management to increase health insurance costs beginning in 2018.

Triumph officials were not available for comment Monday night.

The union also accused Triumph executives of accepting Washington state tax credits and then moving jobs to Mexico.

The aerospace business is booming, said union President John Holden, and wages and job security should be rising – not falling.

Machinists last went on strike in Spokane for three days in 2007.

Triumph, headquartered in Pennsylvania, bought the factory from Boeing in 2003.