Presentation of research project DIFT:

Over the last years, EASA has been made aware of incidents during the take-off of anti-iced aircraft. The incidents have been reported for various aircraft types, mainly aircraft with unpowered flight controls and low-medium rotation speeds. The pilots typically reported these incidents as difficulties or incapability to rotate the aircraft at Vr.

The Swedish accident investigation body investigated a related serious incident and made safety recommendations to EASA.

To address one of the recommendations, EASA launched a research project aiming to replicate the phenomena, understand the causes of the reported events and establishing the most adverse conditions. In the research project, an aerodynamic model representing a horizontal stabiliser was exposed to an accelerated stream in a wind tunnel modelling the actual conditions of a typical aircraft during a take-off run and the stabiliser lift and elevator hinge moments were measured over time to assess the impact of the applied anti-iced fluids.

More information in the provided documents.