What is RTC on Boeing 737? (Rudder Trim Control)

The Rudder Trim Control (RTC) is an essential feature on the Boeing 737 aircraft that allows pilots to adjust the position of the rudder trim tab. The rudder trim tab is a small movable surface located on the trailing edge of the vertical stabilizer, or the fin, at the back of the aircraft. It works in conjunction with the rudder to help the pilot maintain balanced flight and control the yaw movement of the aircraft.

The rudder trim control is primarily used for two main purposes: to eliminate the need for continuous manual rudder pedal input during flight and to counteract any yaw or directional imbalances caused by various factors such as engine thrust asymmetry, unequally loaded cargo or passengers, or fuel imbalances. By adjusting the rudder trim control, pilots can optimize the aircraft’s aerodynamic performance, improve fuel efficiency, and enhance overall flight stability.

How Does the Rudder Trim Control Work?

The rudder trim control on the Boeing 737 is typically operated through a control wheel or a control panel located on the cockpit’s center console. It allows the pilot to adjust the position of the rudder trim tab, which in turn changes the aerodynamic forces acting on the vertical stabilizer. This adjustment modifies the rudder’s neutral position and helps neutralize any yawing moments caused by external influences.

When the aircraft experiences yawing tendencies due to factors like engine thrust asymmetry or uneven weight distribution, the pilot can use the rudder trim control to counteract these imbalances. By applying the necessary rudder trim, the pilot can minimize the need for continuous rudder pedal inputs to maintain coordinated flight. This reduces pilot workload and enhances overall flying experience for both the crew and passengers.

Additionally, the rudder trim control is also useful during various flight phases, such as takeoff and landing, where precise control of the aircraft’s yaw is crucial. For example, during takeoff, the rudder trim can be adjusted to counteract any yawing moments caused by the asymmetrical engine thrust. This ensures a smooth and coordinated takeoff, allowing the pilot to maintain control of the aircraft’s heading.

Importance of Proper Rudder Trim Control

Proper rudder trim control is crucial for safe and efficient flight on the Boeing 737. Failure to appropriately adjust the rudder trim can lead to handling difficulties, increased pilot workload, and compromised aircraft performance. It is essential for pilots to have a thorough understanding of the rudder trim control system and its operation to ensure they can effectively manage any yaw imbalances during flight.

One common scenario where the importance of rudder trim control becomes evident is during engine failure. In the event of an engine failure, the remaining operating engine generates uneven thrust, leading to an asymmetrical force distribution that can cause the aircraft to yaw. The pilot must promptly adjust the rudder trim to counteract this yawing moment and maintain control of the aircraft’s direction.

Furthermore, proper rudder trim control is necessary to maintain fuel efficiency. Misaligned rudder trim can result in increased drag, causing the aircraft to consume more fuel than necessary. By correctly adjusting the rudder trim, pilots can minimize drag and optimize the aircraft’s fuel consumption, ultimately reducing operational costs and environmental impact.


The Rudder Trim Control (RTC) plays a vital role in maintaining balanced flight and managing yaw imbalances on the Boeing 737 aircraft. It allows pilots to adjust the position of the rudder trim tab to optimize flight stability, reduce pilot workload, and enhance overall aerodynamic performance. Proper understanding and utilization of the rudder trim control system are essential for safe and efficient flight operations.

Next time you board a Boeing 737, take a moment to appreciate the intricacies of the rudder trim control, knowing that it contributes to a smoother, more comfortable flight experience.

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