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This paper analyzes the effects of the helicopter dynamics on pilots' learning process and transfer of learned skills during autorotation training. A quasi-transfer-of-training experiment was performed with 10 experienced helicopter pilots in the SIMONA moving-base flight simulator at Delft University of Technology. Pilots had to control an in-house flight dynamics model setup to simulate two types of helicopter dynamics: (1) a "hard" dynamics characterized by a low autorotative flare index requiring high pilot control compensation and (2) a "easy" dynamics characterized by a high autorotative flare index with low pilot control compensation required. Two groups of pilots tested these types of dynamics in a different training sequence: hard-easy-hard (HEH group) and easy-hard-easy (EHE group). The main conclusion of this study proved that simulator training for autorotation can best start with pilots training in the most resource demanding condition. A more challenging helicopter's dynamics will require higher pilot agility and more rapid responses to his/her perceptual changes. This will result in pilots developing more robust and adaptable flying skills. Indeed, a clear positive transfer of training effect was observed in the experiment presented in this paper in terms of acquired pilot skills in the HEH group, but not the EHE group. Positive transfer was especially observed in terms of reduced rate of descent at touchdown. The two groups differed in the control strategy applied, with the HEH group having developed a control technique mimicking more closely the one adopted in a real helicopter. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to examine the mathematical modeling of the helicopter flight dynamics for simulator qualification and to reveal new insights into the mathematical model's response fidelity. The paper will focus on the qualification process of the simulator mathematical model as given by joint aviation requirement STD-1H, the European standard for helicopter simulator qualification. Using the joint-aviation-requirement tolerances, defined as acceptable differences between the model results, the flight test data, and the critical-pole-distance method developed at Delft University of Technology for predicting the necessary degrees of freedom of a simulation model, the paper will perform a sensitivity study on the pitch tolerances specified by the joint-aviation-requirement regulation, investigating how these tolerances might affect the model level of detail. It will be demonstrated that depending on the rotor system, the tolerances may or may not affect the helicopter flight dynamics behavior. For an articulated centrally hinged rotor, it will be shown that the tolerances have very little effect on the level of detail used in the modeling; for a hingeless rotor, variations in the model from an uncoupled flap-body dynamics to a coupled flap-body result in large variation in the simulation results and handling-qualities characteristics.

This paper analyzes the effects of the helicopter dynamics on pilots' learning process and transfer of learned skills during autorotation training. A quasi-transfer-of-training experiment was performed with 14 experienced helicopter pilots in a moving-base flight simulator. Two types of helicopter dynamics, characterized by a different autorotative index, were considered: "hard," with high pilot compensation required, and "easy," with low compensation required. Two groups of pilots tested the two types of dynamics in a different training sequence: hard-easy-hard (HEH group) and easy-hard-easy (EHE group). Participants of both groups were able to attain adequate performance at touchdown in most of the landings with both types of dynamics. However, a clear positive transfer effect in terms of acquired skills is found in both groups from the hard to the easy dynamics, but not from the easy to the hard dynamics, confirming previous experimental evidence. Positive transfer is especially observed for the rate of descent at touchdown. The two groups differed in the control strategy applied, with the HEH group having developed a more robust control technique. During the last training phase the EHE group aligned its control strategy with that of the HEH group. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to give a basic understanding of the mechanisms through which pilot cyclic inputs in lateral cyclic interacts with high-order rotor dynamics destabilizing the helicopter roll motion. The paper will use a "Newtonian formulation" representing the main forces acting on the airframe body-rotor system as the pilot applies his/her control. It will be demonstrated that pilot lateral controls applied through his/her arm (which may involve also pilot biodynamics, i.e. the dynamics of pilot neuromuscular inputs and contraction dynamics of his/her muscles) may excite much higher-order frequency rotor dynamics than thought at the present. [ABSTRACT FROM AUTHOR]

ABSTRACT The aim of this study is to assess the load predicting capability of a classical Beddoes-Leishman dynamic stall model in a horizontal axis wind turbine environment, in the presence of yaw misalignment. The dynamic stall model was tailored to the horizontal axis wind turbine environment and validated against unsteady thick airfoil data. Subsequently, the dynamic stall model was implemented in a blade element-momentum code for yawed flow, and the results were compared with aerodynamic measurements obtained in the MEXICO (Model Rotor Experiments under Controlled Conditions) project on a wind turbine rotor placed in a large scale wind tunnel. In general, reasonable to good agreement was found between the blade element-momentum model and MEXICO data. When large yaw misalignments were imposed, poor agreement was found in the downstroke of the movement between the model and the experiment. Still, over a revolution, the maximum normal force coefficient predicted was always within 8% of experimental data at the inboard stations, which is encouraging especially when blade fatigue calculations are being considered. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]