The T-bar cyclic control in the Robinson series helicopters is a departure from the typical flight-control design, however, its collective control conforms to industry standards. I know of only one manufacturer that has designed and installed a collective control that differs from the norm. Bell Helicopter certified the twin-engine model 222 in 1979 with a collective control that moves in more of a horizontal arc as opposed to up and down. The pilot pulls the collective rearward to increase pitch and pushes it forward to decrease. Bell used this arrangement on all subsequent variants including the model 430.
When designing the model 222 in the early 1970s, Bell was targeting the business jet community. Thinking the helicopter would appeal to corporate operators, the company believed the new collective design would feel more like a corporate jet. Additionally, Bell claimed the unique collective lever reduced pilot effort and enhanced safe operation. Also according to company documents, the near horizontal arc is perpendicular to any vertical rotor system vibrations which eliminate any pilot induced oscillations.
The twist-grip engine throttles are located on the collective, however, they are perpendicular (canted aft about 10 degrees to make for a comfortable grip) to the collective shaft as opposed to the standard in-line arrangement. This left/right design works well with the cockpit engine instruments making identification of the correct engine with its corresponding throttle very easy.
When I started flying a Bell 430, the collective movement was natural and instinctive from the beginning. Throttle friction is adjustable, so I never had an issue with inadvertently twisting the throttles while making collective changes. Although the standard up and down collective control works fine, I do like the arc motion better.
Tags: Tim McAdams