As aircraft takes off and lands, the controlling forces that provide the choice and sustainability of flight direction are enabled by deflection of control surfaces. They allow a pilot to cope with different emergencies, for example, when one of the engines fails.

Today, TsAGI (a part of NRC “Zhukovsky Institute”) scientists are researching into the ways of increasing efficiency of aircraft controls. The research is being carried out under a state contract with the Ministry of Industry and Trade of the Russian Federation within the Technologies—Transport—2 R&D.

At the first stage, TsAGI’s Specialists for Aircraft Aerodynamics designed a wing section structure with different aerodynamic controllers. The structure included such units as deflectors or leading-edge droop flaps. Profile of the load-bearing surface was also improved. The next step was the manufacturing of small-scale metal section model with about 1.4-meter span.

‘Airflow separation occurs at aerodynamic controls when they are deflected at a large angle to control the aircraft, so their performance decreases and aircraft controllability is compromised. This phenomenon can be eliminated with our structure that uses deflectors and droop flaps. Furthermore, we expect a reduction in hinge moment that usually requires more powerful control actuator or more force applied by pilot at manual control,’ said Cand. Sc. Vladimir Bogatyryov, Head of Sector, Department for Aircraft Aerodynamics, TsAGI.

The wing section with controls was tested in the T‑103 wind tunnel. The influence of the developed modifications on model flow was studied at the takeoff/landing mode at the velocity of 50 m/s and with the angles of attack from —5 to 20 degrees. The performance of the aerodynamic controls increased by 1.5–2 times.

The next stage of the research is expected to take place in 2024. It is planned to manufacture a full-scale load-bearing surface model with controls, and to study the model considering drive connections.