The second prototype of the Harbin Z-9W (c/n Z-9W-02 and serialled '043 Black') had its maiden flight in 1989 and went into production.  The attack helicopter entered service with the PLA Army Aviation Corps as the first Chinese helicopter capable of destroying armored targets; about 80 were initially delivered.
The exact month and day are unknown and will be updated.

Yefim Gordon, Dmitriy Kommissarov.  "Chinese Aircraft: China's Aviation Industry Since 1951".  Hikoki Publications Ltd., 2008.  Pg. 280. Print.