The paper concerns the severity of the response of a rotorcraft encountering the vortex of a fixed-wing aircraft. One of the key questions is whether a rotorcraft designed to meet handling performance standards will have sufficient control margin for the pilot to overcome the effects of a vortex encounter. This question is addressed through an analytical study supported by preliminary piloted simulation tests. The handling qualities criteria are found to be well suited to establishing the severity and associated hazard category of typical encounters. Cases are illustrated where insufficient control margin is available to overcome the effects of the encounter. Pilot intervention time is a critical parameter in the upset severity. In risk assessment parlance, the work suggests that an intervention time of 3 seconds leads to HAZARDOUS encounters ( > Level 3 handling qualities) while with a reduced intervention time of 1.5 seconds, the encounter severity is more likely to be in the MAJOR category (Level 3 handling qualities).
A severity analysis for rotorcraft encounters with vortex wakes
Eine Belastungsanalyse für Hubschrauber bei Wechselwirkung mit Wirbel-Nachläufen
Journal of the American Helicopter Society ; 49 , 4 ; 445-456
2004
12 Seiten, 19 Bilder, 5 Tabellen, 16 Quellen
Article (Journal)
English
A Severity Analysis for Rotorcraft Encounters with Vortex Wakes
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