Jet transport response to a horizontal wind vortex

The dynamic response of a twin-jet transport aircraft encountering a horizontal wind vortex (or rotor) on final approach to landing is investigated. Computer simulations determine the effects of vortex strength, vortex length, lateral entry position, vertical entry position, and encounter incidence angle on the aircraft’s roll response. Maximum roll rate and roll angle increase proportionally with vortex strength and length until a saturation length is reached. Roll response is highly dependent on entry location: changes in lateral entry position largely affect maximum roll angle while changes in vertical entry position affect maximum roll rate. Peak roll rate and roll angle obtain their largest values at near-zero incidence angles. The response is highly dependent on the precise initial conditions of the encounter–even small variations in initial condition cause significant changes in aircraft roll response.