The Ural Civil Aviation Plant is building the LMS-901 Baikal light multipurpose aircraft for local flights. Within the framework of its certification, the Central Aerohydrodynamic Institute (TsAGI) named after N.E. Zhukovsky examined the plane’s behaviour in overcritical flight modes.
Earlier, specialists from TsAGI conducted a series of tests of LMS-901 model in low-speed wind tunnels T-102 and T-103. The flight performance of the “Baikal” and its airflow characteristics were studied. In addition, there was a tube experiment with a screen which evaluated the effect of the proximity of the ground surface on the take-off and landing characteristics. The institute’s staff also tested the efficiency of the LMS-901 controls in all flight modes.
At present, the main task of TsAGI has become the calculation-experimental research of aircraft behaviour at high angles of attack. “In the T-103 wind tunnel we studied the non-stationary aerodynamic characteristics of the Baikal at critical flight regimes – at angles of attack up to 30 degrees and sliding up to 25 degrees. Scientists of the institute tested the model aircraft in a vertical wind tunnel T-105 in the mode of corkscrew – at angles of attack up to 90 degrees “, the TsAGI press service said.
“The aircraft is planned to be certified in 2023. In order to pass this procedure, it is necessary to confirm the maximum permissible angle of attack in flight. To enable this to be done during flight tests, the critical modes are first simulated in the wind tunnel on the ground. Thanks to the recommendations prepared at TsAGI, the pilot will be prepared for atypical machine behaviour in certain situations and will be able to achieve angles of attack that will become valid,” said Alexander Kornushenko, Head of the Department of Aircraft Aerodynamics at TsAGI.
In addition, the institute conducted studies aimed at refining the flap, improving the local aerodynamics of the aircraft and the elimination of small tear zones at the junction of the wing with the fuselage and struts. Based on the results of all experiments, TsAGI specialists will prepare and submit to the customer recommendations for piloting techniques to stop or prevent stalling and recovery from an unintentional stall for the final certification tests of LMS-901 Baikal.
