Boeing has sent a letter to the homes of production workers getting ready to vote Friday on the company's contract extension proposal.

KING-TV reports the letter from Boeing Commercial Airplanes human resources Vice President Alan May says approval "will secure jobs in the Puget Sound region for the next decade and beyond."

May says ratification will mean Boeing will agree to both fabricate and assemble the wings of its new 777X jet -- and build the new jet -- in the Puget Sound area.  The letter says construction work will include building the fuselage, final assembly and work on major components such as interiors and wiring.

Boeing says mechanics who now build aluminum wings will be trained to build new composite wings.

The contract proposal would freeze existing pensions and deny fixed pensions to new employees.

Since Machinists rejected an initial contract offer in November, 22 states have submitted bids to secure work on the new jet.