The Sikorsky Support Services, Inc. employees build and repair helicopters for the military.
Union representatives said the company's contract offer was unacceptable. Worker's health benefits are just one of the sticking points.
The company had recently announced it had landed a $1.5 billion contract to build 80 Blackhawk Helicopters for the Army and 82 helicopters for the Navy.
The strike involves about 105 helicopter mechanics represented by the teamsters union.
A spokesman at the company headquarters in Connecticut said he's disappointed the contract was rejected.