The results of preliminary tests concerning estimation and widening of helicopter limiting manoeuvre abilities are presented. Research space applies to super‐ and hipermanoeuvrability problems that are especially important for helicopters, because of better manoeuvrability influence on higher safety level and effectiveness in special applications. In airplane engineering, these types of tests are advanced and aerodynamic system improvements are introduced as well as thrust vector control. There are also new manoeuvres recognized for advanced manoevrability airplanes: Cobra, Kulbit, Hook, Bell, Herbst manoeuvre. Although helicopter is “originally” thrust controlled, systematic researches on this field are still not conducted. The paper deals with the problem of helicopter flight mechanics at low flight speeds. The purpose of performed analysis is to achieve possibility of helicopter angular position control within wide range of angular displacements. This is performed by linear and centrifugal acceleration control. Rotor thrust vector control makes those accelerations appear.

The paper generally discusses Whirl Tower research stands. Whirl Tower stands are used to test, among others, rotorcrafts main rotors in hovering. The work presents an overview of similar solutions of test stand presented in the available literature and online data. Beyond these solutions the paper also contains test stands used so far at the Institute of Aviation, these solutions were prepared for testing one type of rotor (for example: only for gyroplane rotors). The article provides information about new (Whirl Tower) test stand fully designed and manufactured in Łukasiewicz Research Network ‒ Institute of Aviation (Ł-ILOT). One of the basic assumptions is that it will be a universal test stand, giving the possibility to test different types of rotors. Moreover, the article discusses the types of tests and research that can be carried out on this type of test stand, tests that are performed to ensure the safety of the rotor design.

No abstract

Unsteadiness of pressure in a helicopter rotor slipstream may bring a significant problem during operation from the elevated heliports, as the oscillating slipstream acts on the heliport plate and causes vibration of building's structure (Ref. 1). However, still it is an unappreciated issue, discussed mainly in the literature focused on the brownout (e.g. Nathan and Green (Ref. 2), Ramasamy et al (Ref. 3)). In this case researchers usually neglect the loads acting on the ground. On the other hand, investigation of interaction between rotor slipstream and helicopter's surroundings (e.g. Gibertini et al. (Ref. 4), Dziubinski (Ref. 5)) is often limited to a time-averaged case. The investigation presented below has been carried with the 2-bladed rotor, having diameter of 8 meters, in conditions of IGE hover. Pressure measurements showed that the amplitude of its oscillations is nearly constant along the radius of the rotor and achieves the value up to 30% of the disc loading.