Vortex Ring State Briefing -Italian-

1. A CURA STV SANTAGATI DARIO

4. Vortex Ring State - Anello Vorticoso - Il VRS è un incontrollato rateo di discesa causato da un flusso d’aria turbolenta che si sviluppa Ogni volta che l’elicottero effettuando un avvicinamento ripido ed a bassa velocità, discende attraverso il proprio Flusso Indotto. In questa condizione, nonostante ci sia ancora potenza disponibile l’elicottero continuerà a scendere con velocità variometriche molto elevate.

7. Vortex Ring State - Anello Vorticoso -

10. “ Figure 11-7 shows a sequence of events based upon interpretation of the smoke patterns. According to this model, the rotor is continually pumping air into a big bubble under the rotor. This bubble fills up and bursts every second or two, causing large-scale disturbances in the surrounding flow field. The bubble appears to erupt from one side and then another, causing the rotor thrust to vary and the rotor to flap erratically in pitch and roll, requiring prompt reaction. This is what causes the loss of control effectiveness. Recovery includes lowering the collective and forward cyclic to fly out of the condition. Increasing the collective only serves to aggravate the situation.” Fonte Advanced Rotary Wing Aerodynamics –US NAVY--

12. Vortex Ring State - Anello Vorticoso - MANUALE DI PILOTAGGIO AB 212

13. Vortex Ring State - Anello Vorticoso -