MODIFICATION TO THE HAWKER HUNTER’S EJECTION SEAT DESIGN TO IMPROVE PILOT SAFETY

THE PROJECT

Owning and operating a unique fleet of special Hawker Hunter fighters, Lortie Aviation aims to extend the working life of this complex transonic aircraft and provide its customers with a safe flight environment.

With multiple recent cases of ejection leading to severe injuries, Lortie Aviation mandated Creaform Engineering to study the seat design and identify the current risk of severe back injuries during pilot ejection. Lortie Aviation also entrusted the team of engineers with the task of proposing design corrections and mitigation strategies for reducing impulse acceleration and peak magnitude transferred to the pilot body.

Creaform Engineering employed explicit numerical simulation using LS-Dyna software to reproduce the dynamics of pilot ejection with a Martin-Baker seat on board a Hawker Hunter fighter. In addition, the numerical simulation experts used a simplified anthropomorphic test device (ATD) model with specific kinematics and kinetics outputs to establish the risk of injury and a biofidelic numerical dummy (THUMS 50th male model) to see the effect of ejection dynamics on physiological structures. This way, the team could monitor the acceleration and forces transmitted from the seat to the pelvis and spine. The engineers also carried out a complete scan of the seat and the foam cushions and used the 3D scan data to carefully position the numerical models.

Based on the finite element models, the numerical simulation experts proposed improvements to the seat design to reduce the energy transmitted to the pilot during seat firing. They also demonstrated that these modifications offered better temporal distribution of forces and acceleration. Convinced that all these numerical simulations and analyses on models and biofidelic dummies could reduce the risk of spinal injuries, Lortie Aviation chose to proceed with the new seat configuration.

Read the whole story here.

Services delivered

• 3D scanning
• 3D modeling for reverse engineering the pilot seat
• Physical tests for material characterization
• Numerical simulation, more precisely explicit finite element analysis (FEA) using LS-Dyna

GALLERY