The deal, a follow-on to a $2 million agreement last year between the companies, is worth as much as $2.3 million.
The windows are of two-piece construction located just behind the pilot seat on each side of the aircraft. They slide open for use by the machine gun operator.
CPI Aerostructures said deliveries are expected to start in the first half of 2012 and end in early 2013.
More than 3,000 Sikorsky Black Hawk multi-mission helicopters are in use, operating in 29 countries. Among the mission configurations it serves are troop transport, medical evacuation, electronic warfare, attack, assault support and special operations.
CPI Aerostructures is engaged in the contract production of structural and other aircraft parts for leading prime defense contractors, the U.S. Air Force and other branches of the armed forces.