Senior Autonomous Flight Simulation Engineer

Grex Defense, Inc.; Northern (KY); Hybrid; USD 110,000 - 170,000; Full time

Job summary

Grex Defense, Inc. seeks a hands-on Senior Simulation Engineer to architect, develop, and deploy simulation capabilities for autonomous aircraft design and testing.

You will connect aerodynamic data, vehicle dynamics, controls, actuation, and environment models within an integrated SIL workflow. This role requires deep expertise in MATLAB/Simulink, C/C++, nonlinear 6-DOF simulations, and model verification, with a track record of building simulation tools for real-time execution and flight-test

Qualifications

• Significant professional experience developing flight-vehicle or other complex dynamic-system simulations.
• Expert proficiency with MATLAB and Simulink.
• Strong software development in C and C++, including MATLAB/Simulink integration.
• Experience architecting nonlinear six-degree-of-freedom simulations.
• Understanding of rigid-body and multi-body dynamics, equations of motion, numerical integration.
• Experience designing SIL environments for control, autonomy, or embedded software.
• Knowledge of model linearization, state-space analysis, PID control architectures, gain scheduling, controller tuning, and stability analysis.
• Strong understanding of actuator dynamics, sensor behavior, nonlinearities, delay, latency, bandwidth, sampling rates, and real-time execution constraints.
• Experience building automated test harnesses, regression tests, Monte Carlo simulations, and model-verification frameworks.
• Experience developing aerodynamic databases from CFD, wind-tunnel, lower-order analysis, or flight-test data.
• Experience creating surrogate surfaces, response surfaces, reduced-order models, or ML-based representations of complex datasets.
• Ability to move between high-fidelity CFD data and computationally efficient real-time simulation models.
• Working knowledge of lower-order aerodynamic methods: lifting-line theory, vortex-lattice, panel methods, or comparable physics-based approaches.
• Understanding of atmospheric, wind, turbulence, gust, and other environmental disturbance models.
• Experience modeling actuator and control-system behavior: saturation, rate limits, deadband, backlash, compliance, delay, and bandwidth.
• Ability to investigate complex simulation behavior, isolate root causes, and communicate model assumptions, limitations, and findings.
• Ability to develop tools and processes from a clean sheet in a fast-paced startup environment.
• Ability to work collaboratively across aerodynamics, GNC, autonomy, propulsion, systems, software, and flight-test disciplines.
• U.S. person status under U.S. export-control law (ITAR/EAR).

Responsibilities

• Architect, develop, and deploy the simulation capabilities required to design and test autonomous aircraft.
• Connect aerodynamic data, vehicle dynamics, controls, actuation, environmental models, and visualization within an integrated simulation environment—designing software-in-the-loop (SIL) systems.
• Establish simulation workflows and standards and build models that progress from conceptual analysis to real-time execution and flight-test support.
• Mentor engineers, help define key hires, and build a simulation organization capable of supporting multiple vehicle programs.

Skills

Flight-vehicle simulations

MATLAB

Simulink

C and C++

Nonlinear 6-DOF simulations

SIL environments

Dynamics modelling

Test harnesses & regression tests

Aerodynamic databases

Surrogate models / ML representations

Real-time execution

Coordinate transformations / reference

Model linearization / state-space /PID

Actuator & sensor dynamics

Verification frameworks

CFD/wind-tunnel data handling

Tools

MATLAB/Simulink

Job description

Grex Defense, Inc. seeks a hands-on Senior Simulation Engineer to architect, develop, and deploy simulation capabilities for autonomous aircraft design and testing.

You will connect aerodynamic data, vehicle dynamics, controls, actuation, and environment models within an integrated SIL workflow. This role requires deep expertise in MATLAB/Simulink, C/C++, nonlinear 6-DOF simulations, and model verification, with a track record of building simulation tools for real-time execution and flight-test