  Specific gust response is considered as one of the most important loads
encountered by an aircraft. The Certification Specification (CS) 25, defined by
the European Aviation Safety Agency (EASA), and the Federal Aviation
Regulations (FAR) 25, defined by the Federal Aviation Administration (FAA),
describe the critical gusts that an aircraft must withstand. They must be
analyzed for a large range of flight points (Altitude and Equivalent Air speed)
and mass configurations. For some load cases, the standard tools could not be
accurate enough to correctly predict the gust response and the use of
high-fidelity computation could be required. Therefore, ONERA has implemented
in its in-house Computational Fluid Dynamics (CFD) code elsA
(ONERA-Airbus-Safran property) the capability to compute the high-fidelity
aeroelastic gust response, directly in the time-domain, for different discrete
gust shapes.This paper presents some recent work achieved at ONERA concerning
high-fidelity simulations for gust response. First, a physical validation of
the gust response simulation is performed by comparing the results to those
obtained experimentally on a scaled model. Second, numerical comparisons are
performed using various techniques, in order to model the gust. Finally, an
application for generic regional aircraft is shown.
