Authored By Dan Alex (Updated: 4/25/2016):
Little Bird Origins
Little Bird development stemmed from a 1960 US Army requirement looking for a versatile transport and light attack helicopter. This requirement fell under "Technical Specification 153" and itself was part of the US Army's/US Navy's Light Observation Helicopter (LOH) program. Hughes submitted their Model 369 as one of a dozen firms totaling some 19 design proposals (25 firms were initially solicited). By October of 1961, the US Army, with input from the US Navy, selected three of the designs for further evaluation - these being the Bell D-250, the Hiller Model 1100 and the Hughes Model 369. The US Army liked what it had in the Bell D-250 while the US Navy was interested in the Hiller Model 1100. All three were assigned respective new designations as the YHO-4, YHO-5 and YHO-6 and constructed as five evaluation prototypes. Flight testing occurred at Camp Rucker, Alabama. All systems were later redesignated under the new DoD system in 1962 as the YOH-4, YOH-5 and YOH-6.
The Bell YHO-4 was eventually eliminated from contention to which the Hiller YOH-5 and Hughes YOH-6 were left to battle it out. Ultimately, Hughes was awarded the production contract in 1965 and the YOH-6 now became the OH-6A "Cayuse". An initial order for 714 production systems was later increased to 1,300. In civilian form, the OH-6 was marketed as the Hughes 500, to which several military forms were developed for export - the first of these becoming the Hughes 500M to Columbia.
Original production fell under the Hughes Helicopters, Incorporated banner but McDonnell Douglas' purchase of Hughes in 1984 forced a renaming of the brand to McDonnell Douglas Helicopter Company. In 1985, the company was renamed yet again as McDonnell Douglas Helicopter Systems. In 1997, McDonnell Douglas merged with Boeing Company. Boeing proceeded to sell the civilian portion of the helicopter line to MD Helicopter Holdings, Incorporated. In 2005, Patriarch Partners LLC bought the company and reinvented it as the independent MD Helicopters, Incorporated.
The New Requirement
By 1980, the need for a lightweight, easily transportable helicopter system to be crewed by specially-trained personnel operating as a part of the special forces was realized. The OH-6A was evolved into a specialized form to be known as "Little Bird". Select pilots were trained and soon placed into the newly-formed 160th Aviation Battalion (aka "Night Stalkers"). Two Little Bird forms were then developed - one to assist in transporting a small group of operatives into and out of hot zones (the MH-6) and another to support such actions in a light attack role (the AH-6).
Little Bird Walk-Around
The external appearance of the Little Bird is as utilitarian as it gets. The design is dominated by the large bubble-type framed glass cockpit that allows for excellent visibility out of the two-man cockpit. The cockpit resides just forward of a small crew cabin area (MH-6) with placement for up to 6 combat-ready operatives on "bench" type seating along the outboard sides of the cabin fuselage. Rear of that is the housing for the powerplant. The powerplant consists of a single Allison-brand T63-A-5A or T63-A-700 series turboshaft engine rated at 650 full horsepower and powering a five- or -six blade main rotor (depending on the model) as well as a two- or four-blade tail rotor. The main rotor sits atop the fuselage on a short mast while the tail rotor is set to the portside of the aircraft off of the slender and short tail section. The tail is characterized by the complex "T" style assembly made up of a single vertical tail fin topped by a horizontal plane, itself affixed with two small vertical planes. The engine exhaust port, though typically fitted above the tail section in most other helicopters, actually sits under the empennage base in the Little Bird. The weight of the entire aircraft when on the ground is displaced across two rudimentary skids braced in two locations. The skids serve the Little Bird well in providing a handy step area for operatives hitching a ride. Little Birds are commonly painted over in black to reflect their clandestine operation suite.
Performance specifications from the single engine allow the Little Bird a top speed of 175 miles per hour with a cruise speed of 155 miles per hour. Her range is listed at 267 miles with a service ceiling of 18,700 feet and a rate-of-climb equaling 2,061 feet per minute. Internal fuel is reported at 62 US gallons. Operating weight is 1,509lbs with a maximum takeoff limit of 3,100lbs. When completely "clean", the Little Bird weighs in at a respectable 1,591lbs. Its size and weight make it a relatively easy transportable system when moved via the existing American aircraft transports on hand.