The first phase of production eventually will lead to the manufacture of 690 of the new Apache Block III aircraft for the Army, Boeing officials say.
The contract was hailed as a major boost to the southeast Valley's economy and to the continued stabilization of Boeing's Mesa operations.
Mesa Mayor Scott Smith said it represented "a segment of economic stability that goes out for the next 10-plus years."
Boeing spokeswoman Carole Thompson said "it's beyond huge."
A memorandum signed by Defense Department officials last month authorized the program to enter "Low Rate Initial Production" to produce 51 of the Apache Block III aircraft. Delivery of the first helicopter is scheduled for October 2011. A separate contract with the government signed on Oct. 22 covers production of eight helicopters.
The Army's objective calls for delivery of 690 of the new Apaches, which could extend production for nearly a decade or more, Thompson said.