The Bell 406 resulted from the US Army Helicopter Improvement Program (AHIP). Airframes received a upgraded transmission and engine, a four-bladed main rotor and the distinctive Mast-Mounted Sight (MMS) above the rotor system.
The Kiowa Warrior distinguishes from the original AHIP model when carries the weapons pylon mounted on both sides of the aircraft
Model News
US Army OH-58D Kiowa Warrior Final Flight, 19-Sep-17 : The US Army Aviation Development Directorate flew the Army’s final OH-58D Kiowa Warrior flight from Felker Army Airfield at Joint Base Langley-Eustis on September 19, 2017
Croatia Receiving OH-58D Pilot, Maintainer Training, 13-Feb-17 : U.S. Mission and Installation Contracting Command (MICC) in charge of pilot and maintenance training of 16 former US Army Bell OH-58D Kiowa Warrior helicopters to Croatia
Eleven ex-US Army Kiowas Delivered to Croatia, 06-Dec-16 : Croatia received 11 Bell OH-58D Kiowa Warriors in a $50 million foreign military sales by the U.S. Army Security Assistance Command
Last OH-58D Kiowa Aviator class to graduate, 25-Aug-14 : FORT RUCKER, Alabama By Nathan Pfau - A legacy decades in the making is coming to an end, as eight students from Fort Rucker's last OH-58D Kiowa Warrior class prepare to graduate.
Heroes of Aviation Series: Bell Honors OH-58 Kiowa Warriors, 19-Apr-11 : Fort Worth, TX - Bell Helicopter, a Textron Inc. company, announced the Bell Helicopter "Heroes of Aviation" Series which pays tribute to the men and women who preserve freedom and save lives while using Bell Helicopters.
83-24129 : US Army cnvt. from ex OH-58A 69-16169 
20aug90 w/o near air base Dharan 
US Army, conv from ex OH-58A ???; 03jul93 pictured with+ 
oh-58f conv to OH-58F ?