SARAH is concerned with establishing novel holistic, simulation-based approaches to the analysis of aircraft ditching. It is build up from a consortium of experts from OEM industries, experienced suppliers of simulation technologies, established research institutions and representatives of the certification authorities.

The Challenges

Aircrafts and helicopters often travel above water and thus have to prove a safe landing under emergency conditions. The specific challenge is to minimize the risk of injury to passengers and to enable safe evacuation. Accordingly, the motion of the aircraft/helicopter along with the forces acting on the structure are studied for controlled water impact during the design phase of an aircraft.

Ditching has close links with crash simulation, but also distinctive features. Examples refer to hydrodynamic slamming loads on airborne vehicles and complex hydromechanics (partially at very large forward speeds) as well as the interaction of multi-phase fluid dynamics (involving air, water, and vapor phases) and structure mechanics.

Design for ditching involves more than the analysis of loads and subsequent strengthening of the structure. It often requires adjustment campaigns for the handling of the vehicle during approach and the identification of favorable approach/flight-path conditions in line with the pilots flying capabilities to minimize the remaining kinetic energy of the vehicle to be transferred into the water.

In conclusion, a pressing need for more advanced studies to support the development of next-generation, generalized simulation-based ditching-analysis practices is acknowledged by all stakeholders.  Results of SARAH are expected to support a performance-based regulation and certification for next generation aircraft and helicopter and to enhance the safe air transport as well as to foster the trustworthiness of aviation services.

The Objectives

…increase the safety of aircrafts and helicopters in ditching / floatation situations…

• improve aircraft/ helicopter certification tools in order to deliver accurate loads to safely design aircrafts/ helicopters and deliver input on how ditching needs to be simulated in order to obtain robust, safe and accurate loading information
• derive a robust way to safely design new configurations for which no engineering experience is available regarding ditching
• What kind of tools do we need?
• What kind of design is necessary?
• use methods obtained to analyse and optimise approach, landing and impact phases to supporting the pilot in water-landing scenarios

For more information visit: www.sarah-project.eu

The TUHH in the project

TUHH aims to improve their ditching simulation tool DITCH. Emphasis is given to an enhancement of the structural and hydrodynamic load model.

Therefore, high-fidelity CFD tools like FreSCo+ and elbe should be used to train the DITCH tool and get a more thorough understanding of the hydrodynamic details of the ditching process.