Gust Alleviation System
A gust alleviation system (GAS) is a flight control system designed to reduce the impact of turbulence and gusts on an aircraft, improving passenger comfort and reducing structural loads. It works by using sensors to detect changes in air pressure and angular velocity, then sending electrical signals to actuators that power the control surfaces on the wings and tail.
Purpose
The primary goal of a GAS is to mitigate the effects of turbulence and gusts, which can cause uncomfortable vibrations and potentially stress the aircraft's structure.
How it works
- Sensors: The system utilizes sensors, such as accelerometers and rate gyros, to detect changes in air pressure and angular velocity.
- Actuators: Based on the sensor data, the system sends signals to actuators that control the aircraft's control surfaces (ailerons, elevators, rudders).
- Load Alleviation: By precisely controlling the control surfaces, the GAS can counteract the effects of gusts and turbulence, reducing the stresses on the aircraft's structure and improving passenger comfort.
Benefits
- Improved ride quality: Passengers experience smoother rides during turbulence.
- Reduced structural loads: The aircraft's structure is subjected to less stress, leading to increased durability and potentially reduced maintenance costs.
Examples
- The Boeing 787 Dreamliner is equipped with a gust suppression system, which is a type of gust alleviation system.
- The Active Turbulence Suppression (ATS) system for electric Vertical Take-Off and Landing (eVTOL) vehicles employ existing lifting propellers to dampen instabilities during flight, such as Dutch-roll oscillations and other gust-induced oscillations.
Active vs. Passive Load Alleviation
- Active: This involves using control surfaces to actively compensate for the effects of gusts and turbulence.
- Passive: This relies on the aircraft's design and structural characteristics to absorb and dissipate gust loads.