Neville T.,AgustaWestland Ltd.
40th European Rotorcraft Forum 2014 | Year: 2014
In June 2011, Apache AH Mk1 Helicopters of the British Army's 656 Sqn conducted their first raid on Libya, using as their base the Royal Navy's helicopter Carrier HMS Ocean. The Apaches went on to destroy 100 targets over a five month period, all the while based on board the ship. Meanwhile civil operators fly regularly to and from oil platforms and ships in the North Sea, covering large distances overwater, and dedicated naval helicopters are based aboard ships in the most demanding of maritime environments for months at a time. "Marinisation" may be considered the task of making a helicopter platform and its support system capable of operating in the maritime environment, including overwater and to and from ships. This paper explores the stages of marinisation of a helicopter, from the fundamental issues affecting aircraft operating in this environment, to the specification of requirements, through design and testing to declaration of operating limits. A number of case studies are presented showing how different designs have been tailored to meet customer objectives. In addition AWs aspirations for improving maritime operational capability in the future are discussed. Copyright © (2014) by the Royal Aeronautical Society. All rights reserved.
Rezgui D.,University of Bristol |
Lowenberg M.H.,University of Bristol |
Jones M.,AgustaWestland Ltd. |
Jones M.,System Dynamics |
And 2 more authors.
Journal of Guidance, Control, and Dynamics | Year: 2014
The dynamics of rotary wing systems are complex and typically feature highly nonlinear and often unsteady aerodynamics, as well as aeroelastic influences. In ongoing efforts to reduce noise and vibration, active devices such as trailing edge flaps on the rotor blades are being studied and these devices can introduce further nonlinearities. Therefore, it is important to be able to evaluate the stability of the overall systemwith a proper understanding of the global nonlinear behavior. Numerical continuation and bifurcation analysis is well suited to this need, and this paper presents evidence of the technique providing a deeper insight into the stability of helicopter rotor systems than the methods typically adopted in the industry. We first investigate the aeroelastic stability of rotor blades of a medium-sized helicopter in hover and the periodically forced forward flight condition, in both trimmed and untrimmed cases. Then, bifurcation analysis is used to predict the nonlinear stability of a single degree-of-freedom trailing edge flap added to the aeroelastic system, over a range of design parameters. The approach is novel in the context of real-world aeroelastic rotormodels, and the emphasis here is on the potential for revealing important multiple-attractor dynamics rather than the study of a particular system. The results presented highlight the advantages of the approach, both in terms of generating an understanding of local and more global stability, and in the efficiency in obtaining relevant results as parameters vary. Copyright © 2013 by the American Institute of Aeronautics and Astronautics, Inc.
AGUSTAWESTLAND Ltd | Date: 2014-02-25
A device for holding a bearing member relative to a fixed body, including a first part having a formation for engagement with a corresponding formation on a fixed body to hold the first part relative to the fixed body, and a receiving formation for receiving and slidably supporting a generally elongate second part, wherein a first end of the second part is configured for engagement with a part of a bearing member to hold the bearing member relative to the fixed body, and wherein a second, opposite, end of the second part supports an abutment member which prevents the first and second parts separating from each other, wherein the device includes biasing means for biasing the first end of the second part away from the first part.
AGUSTAWESTLAND Ltd | Date: 2012-02-16
A helicopter tail rotor gearbox including a housing, an output shaft for connection to a tail rotor rotatably supported in the housing and having an open end therein, an input member rotatably supported in the housing, gearing providing a power transmitting connection between the input member and output shaft, a pitch control shaft for effecting a change in the pitch of the tail rotor, the pitch control shaft being disposed at least partially within the output shaft, rotatable therewith, and movable relative thereto along the rotational axis of the output shaft, an actuating member for effecting axial movement of the pitch control shaft, the actuating member being movable axially of the output shaft but held against rotation therewith, and a bearing assembly positioned in between the pitch control shaft and the actuating member for permitting relative rotation therebetween, wherein the gearbox includes at least one formation for diverting oil, dispersed within the housing in use, towards the open end of the output shaft.
AgustaWestland Ltd | Date: 2013-08-16
A gearbox including a housing; an input member rotatably supported in the housing; a rotatable shaft supported in the housing; gearing providing a power transmitting connection between the input member and the rotatable shaft; and an oil feed member held against rotation relative to the housing; wherein the oil feed member has at least one helical formation for causing oil within the gearbox to be fed axially of the oil feed member, on rotation of the rotatable shaft.