The Model 300 has roots in a Hughes Helicopter design, the Model 269, which originally attempted to interest the United States Army as a combat-level observation platform to succeed an aging line of Bell OH-13 and Hiller OH-23 types. These were evaluated by the service from 1957 until 1958 under the designation of "YOH-2" but were not adopted due to budget reasons and lack of over-battlefield value. Only in 1964 was the helicopter selected by the service to fulfill a dedicated training role under the designation of TH-55 "Osage" and 792 units were delivered (additional production, 38 units, stemmed from Kawasaki of Japan for the JGSDF).
From this, the Hughes Helicopter design ultimately fell under the McDonnell Douglas (MD) brand label when the company and its assets were absorbed into MD in 1984. In 1986, the Schweizer concern secured the rights to the compact helicopter and the company evolved the line into the "Model 300C" (Model 296C). The initial form carried a Lycoming HIO-360-D1A engine coupled to a larger-diameter main rotor of 26.9 feet (increased from the original's 25.3 feet). This, in turn, increased overall performance for the series which, in turn, led to an increase in global customer interest.
The C-model carried its crew of two in side-by-side seating under and behind a large-view glassed nose. Structural dimensions included a running length of 30.9 feet, a beam (rotor included) of 26.9 feet, and a height of 8.8 feet. Empty weight is 1,100lb against an MTOW of 2,050lb. The HIO-360-D1A engine provides for speeds up to 110 miles-per-hour (cruising near 100 mph), a range out to 205 miles, and a rate-of-climb near 750 feet-per-minute.
Showcasing its strengths as an urban environment performer for law enforcement, the Model 300CQ "Sky Knight" was born for just that market segment. These were outfitted with additional noise-reduction equipment for urban operations, the reduction claiming up to 75% of noise generated by the small helicopter.
The Model 300CB then followed as the first dedicated helicopter development produced by Schweizer itself. Prior to this, the forms were emerging under the Hughes Helicopter/MD Helicopters brand labels. The series switched to a Textron Lycoming HO-360-C1A engine of 180 horsepower and recorded its first-flight on May 28th, 1993. The design was then type-certified in August of 1995, clearing the path for serial production and formal operations in virtually any military or civilian airspace setting.
The "Model CBi" has since been introduced as a fuel-injected version of the Model 300CB. In addition to this, several enhanced survival features are championed with this variant.
The Schweizer Model 300 series has seen operational service with Argentina (Coast Guard), Brazil (military police), Colombia (Air Force), El Salvador (Air Force), Greece (Army), Indonesia (Army), Pakistan (Army), Thailand (Army), Turkey (Army), and the Los Angeles County Sheriff's Department (law enforcement) of the United States. The list certainly showcases the type's inherent design versatility, able to operate in urban or open-country settings as well as over-land or over-water.
The S-330/S-333 is a modernized Model 300 offshoot appearing in 1992. This more modern, sleeker offering is the basis for the North Grumman MQ-8 "Fire Scout" helicopter UAV (detailed elsewhere on this site) and improved, four-bladed Sikorsky S-434 series. Powered by a Rolls-Royce 250-C20W turboshaft engine of 420 horsepower, it is only in service with the Dominican Air Force as well as the Saudi Arabian Army (2019). This two- or three-seat model offers speeds closer to 120 mph, and range out to 365 miles and a rate-of-climb reaching 1,380 feet-per-minute.
In 2004, Sikorsky purchased Schweizer and its assets in order to take full advantage of the latter's ability to prototype helicopter specimens for rapid testing. In 2010, Model 300 production ended which went on to hamper parts distribution and product support - leaving many Model 300 operators to seek alternatives and damaging Model 300 global interest.