Senior Guidance, Navigation & Controls (GNC) Engineer

Grex Defense; United States; Remote; USD 130,000 - 170,000; Full time

Job summary

Grex Defense is seeking an early team member to develop and flight-test inner-loop controls for autonomous aircraft. You will take work from initial control architecture and simulation through embedded implementation, hardware integration, and real-world testing.

You will work closely with design, aerodynamics, autonomy, avionics, propulsion, and test teams to shape the control system, establish workflows, and mature tools and engineering practices used across the program.

Qualifications

• Experience taking a vehicle or robotic system from modeling and simulation through hardware integration and real-world testing.
• Deep knowledge of control design and analysis (PID tuning, gain scheduling, loop shaping, filtering).
• Strong foundation in rigid-body dynamics, nonlinear/state-space methods, MIMO systems, controllability and observability.
• Strong MATLAB and Simulink skills, with working proficiency in C/C++ and Python.
• Experience with system identification, actuator and latency modeling, test data correlation, and high-rate telemetry analysis.

Responsibilities

• Architect, implement, and tune rate, attitude, velocity, and position control laws.
• Build simulation and analysis environments using nonlinear six-degree-of-freedom vehicle models.
• Integrate control software with hardware and support ground tests, flight tests, and field operations.
• Analyze telemetry and test results to identify model discrepancies and guide system changes.
• Develop test harnesses and repeatable verification methods for control systems.
• Collaborate across disciplines and help establish GNC workflows, toolsets, software practices, and technical standards.

Skills

PID tuning

Gain scheduling

Loop shaping

State-space methods

Rigid-body dynamics

MIMO control

MATLAB

Python

C/C++

System identification

Telemetry analysis

Education

Bachelor's degree in aerospace engineering (or related field)

Tools

Simulink

C/C++

Python

Job description

Role overview

Develop and flight-test inner-loop controls for autonomous aircraft, taking the work from initial control architecture and simulation through embedded implementation, hardware integration, and real-world testing. As an early team member, you will help shape the control system and establish the engineering workflows and tools used to mature it. The role works closely across vehicle design, aerodynamics, autonomy, avionics, propulsion, and test.

Responsibilities

• Architect, model, implement, and tune rate, attitude, velocity, and position control laws.
• Build and use simulation and analysis environments, including nonlinear six-degree-of-freedom vehicle models.
• Integrate control software with hardware and support ground tests, flight tests, and field operations.
• Analyze telemetry and test results to identify model discrepancies and guide system changes.
• Develop test harnesses and repeatable verification methods for control systems.
• Collaborate across disciplines and help establish GNC workflows, toolsets, software practices, and technical standards.

Requirements

• Degree in aerospace, mechanical or electrical engineering, robotics, controls, or a related field, plus substantial relevant professional experience.
• Demonstrated experience taking a vehicle or robotic system from modeling and simulation through hardware integration and real-world testing.
• Deep knowledge of control design and analysis, including PID tuning, gain scheduling, loop shaping, filtering, stability margins, and frequency-domain methods.
• Strong foundation in rigid-body dynamics, nonlinear and state-space methods, MIMO systems, and controllability and observability.
• Strong MATLAB and Simulink skills, with working proficiency in C/C++ and Python.
• Experience with system identification, actuator and latency modeling, test data correlation, and high-rate telemetry analysis.
• Ability to work hands-on across disciplines and support vehicle integration and testing.
• U.S. person status under applicable export-control rules.