Published online by Cambridge University Press: 08 April 2020
Rotor Track and Balance (RTB) is an important part of regular helicopter maintenance. The ability to perform this service assessment during normal operations, rather than with a series of explicit RTB flights, would greatly reduce the time the vehicle is non-operational and the maintenance costs associated with these flights and adjustments. This paper presents a novel methodology for identifying the RTB-related flight regimes, using a minimal number of vibration signals and comparing these to repeatable and stable characteristic vibration profiles. The technique is stable, with an 81% success in correct identification of the flight regime, when applied to a whole flight with a number of unknown regime events. The method can be run in real time, making it an effective way of identifying periods of flight that are suitable for RTB measurements. A new technique for visually representing any real-time flight signal, such as vibration, is also presented.