The 67 WAH-64D Apache attack helicopters were built by the merged companies Boeing and McDonnell Douglas (1997) and Westland between 1999 and 2004. The first aircraft was built by Boeing and delivered to the Army in March 1999, followed by the Westland, who built their first aircraft in 2000 and delivered in July 2000. The last aircraft was built and delivered in July 2004.