Wing rock is a potentially hazardous flight condition where an aircraft could lose lateral-directional stability. This occurs in modern combat aircraft at moderate to high angles of attack and is characterized by lightly-damped roll oscillations. The F-104 was one of the aircraft known for this. This is caused by the twin vortices of a Karman sheet moving over the circular cross-section of the aircraft. This behavior is typically restricted to speed ranges in the high-subsonic as well as high-G maneuvers. The matrix equations that describe this dynamic is.
Depending on the flight mode wing rock can be either a nuisance or a hazard to aircraft or mission success. It is sometimes an early sign of departure from controlled flight. Wing rock behavior typically needs control system modifications to attenuate the oscillations.
[[F-104 Starfighter]] – exhibited extensive wing rock
[[Wing Rock Adaptive Controller]]
[[Usable Lift]] – mandates no wing-rock
F-14 Aerodynamics – experienced wing rock at 20-30 deg AOA
[[T-38 Talon]] – wing rock over 10deg AOA
[[X-29 Lateral Directional Model]] – exhibited wing rock above 35 degrees AOA, was stabilized by the flight control system
Sources
- [1] R. Rodríguez, “Concurrent Learning: Boost that Controller Now!,” Geek Culture. Accessed: Oct. 18, 2022. [Online]. Available: https://medium.com/geekculture/concurrent-learning-boost-that-controller-now-9f88a5c48fc
- [2] “Wing Rock Prediction Method for a High Performance Fighter Aircraft”.
Backlinks:
4DoF Dynamic Lateral Aircraft Model
[[Falling Leaf Mode]]
[[Flight Control System]]
[[Linearizing Systems of Differential Equations]]
State-Space Model
Wing Rock