This paper focuses on a novel concept of haptic cueing developed in order to optimize the performance of an Unmanned Aerial Vehicle (UAV) teleoperator and to improve the human-machine interfaces in a mixed obstacle avoidance/wind gust rejection task. It presents an experimental evaluation of two different Haptic aiding concepts: one based on what we called Direct Haptic Aiding (DHA) approach, and a novel one based on the Indirect Haptic Aiding (IHA) approach. The two haptic aids were compared with a baseline condition in which no haptic force was associated to the obstacles (NoEF condition). It will be shown that IHA-based approach definitely improves the pilots' performance with respect to the other approaches. A significant difference in performance (i.e. the number of collisions) was noticed between IHA and both DHA and NoEF conditions. The goal of this paper is to show that the IHA philosophy is a valid alternative to the other commonly used, and published in the scientific literature, approaches which fall in the DHA category.