In 1978 Frank Robinson was granted a patent for a T-bar cyclic flight control system in a helicopter. His concept was a departure from the conventional helicopter flight control design where the cyclic control came up between the pilot’s legs. During the last 30 years the T-bar cyclic in Robinson helicopters has generated a lot of comments.
Robinson’s objective when designing the R22 helicopter was low cost and mechanical simplicity and the T-bar cyclic fits this design goal by reducing the complexity, weight, and cost of the conventional flight-control system. Other advantages include ease of getting in and out of the helicopter and a comfortable flying position as the pilot’s arm can rest on top of his leg. Moreover, not having the control between the pilot’s legs allows for a narrower cabin, which lends to a more aerodynamic fuselage design. Robinson used this arrangement on the larger R44 and the soon to be certified turbine- powered R66.
I have flown many different helicopters with the conventional cyclic design and do not see any difference in the T-bar’s ability to control the helicopter. Also, I agree with the claims of increased comfort while flying and find entering and leaving the helicopter much easier as well. I view it as simply different and believe with just a small amount flight time with the system most pilots will discover that it works quite well.
Still, like all systems, there are unique issues that need to be addressed. One is that the horizontal control bar pivots, allowing the pilot to lower the hand grip to his leg. I have seen pilots struggle with the control’s ability to move up and down while in flight. Once they get comfortable resting their hand on their leg, that goes away. Also, when giving dual instruction–especially to primary students–the instructor needs to pay close attention to the controls and keep his hand close to the cyclic grip, which can be fairly high up when the student is flying. Another point, even with the dual controls removed, is the access the front-seat passenger has to the flight controls. I have had pilots tell me that when giving rides they have had passengers grab or bump the center stick.
The T-bar cyclic works well, however, as with any aviation system, a complete understanding of limitations coupled with good student/passenger briefings is important.
Tags: Tim McAdams