If you ever saw the movie Black Hawk Down, you saw the "Little Bird" kick some serious butt out there. Officially, it comes in two variants, the MH-6 (a small transport that holds as many as nine troops, according to GlobalSecurity.org), and the AH-6 (a small but powerful attack helicopter that usually carries miniguns and Hydra rockets, per GlobalSecurity.org).
A MH-6 Little Bird. (USASOC photo)
These helicopters serve well, but they had an ancestor that is much less known. That was the OH-6 Cayuse, also known as the Loach, which first flew in 1963, according to MilitaryFactory.com. Back then, it was made by the Hughes Tool Company's aviation division, and was known as the Hughes 500 in the civilian market. And yes, that company was owned by the Howard Hughes – mastermind behind the Glomar Explorer and Spruce Goose, among other projects.
This photo of Howard Hughes was taken 25 years before the OH-6 first flew. (Photo from Wikimedia Commons)
The OH-6A was not armed, other than whatever pilots took aboard. But it was small, nimble, and fast. The Army bought over 1,400 choppers, but the Army soon was forced to re-assess its procurement decision. Massive losses in Vietnam (over 650 airframes) and training (297 more) caused the Army to realize they needed a new helicopter.
An OH-6 Cayuse in flight. (U.S. Army photo)
In 1969, the Army bought a version of the Bell 206, which became the OH-58, and which would serve for almost five decades. It seemed like the end, but some U.S. allies bought the OH-6, and some found their way to what would become the 160th Special Operations Aviation Regiment, the Nightstalkers. In the wake of "Desert One," the Army unveiled new versions using an improved version of the OH-6, the first "Little Bird" helicopters to serve America's special operators.
OH-6D with the Japanese Ground Self-Defense Force. (JGSDF photo)