Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-23T22:44:08.807Z Has data issue: false hasContentIssue false

Enabling technologies for a centre-line tiltrotor

Published online by Cambridge University Press:  27 January 2016

B. Burrage*
Affiliation:
Rotorcraft Operations, Oxfordshire, UK

Abstract

The success of the MV-22 Osprey has created the opportunity for a new design of gunship, tailored to the task of escorting it, an opportunity identified by many. Existing and emerging rotorcraft technology does not appear to have the complete capability, so this centre-line tiltrotor approach is aimed specifically at the escort duty.

The mission is taken to be escorting the MV-22 throughout a land assault (Marine Corps), to provide cover while the MV-22 is on the ground at the landing zone, and to still have useful capacity for diversions. To meet this task this Escort concept stays with the same core physics of tilting rotors plus fixed wings of the Osprey, but re-configured for gunship duties. The rotors are removed from the wing tips to mount them on the aircraft centre-line as inter-meshing rotors tilting back one-at-a-time, to act as pusher props in the aeroplane mode. The merits and concerns of this approach are discussed.

The study first reviews present tiltrotor technology and how that may develop. It then reviews what may be achievable from the centre-line tiltrotor configuration, the targets needed in key design parameters and design sensitivities, defining what the enabling technologies must achieve for the Escort. In hover, key areas are rotor disk loading and figure of merit, and also the rotor blockage caused by the fuselage and wings. In winged flight, the proprotor propulsive efficiency and the aircraft lift-over-drag are key, and fundamental to the feasibility of any tiltrotor concept, there is the all important transition process.

At this conceptual stage of the Escort, the transition process stands out as the dominant risk, and one that touches on all the others, so it was decided to build and flight test a model. The flight test programme plans are described and initial flight results reported.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2013 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Wernicke, K.G. Mission potential of derivatives of the XV-15 tilt rotor aircraft, 1981, AGARD paper 19, April 6-9, 1981, Paris.Google Scholar
2. Johnson, W., Benton, H.L. and Bowles, J.V. Calculated performance, stability and maneuverability of high-speed tilting-prop-rotor aircraft, 1986, NASA Technical Memorandum 88349.Google Scholar
3. Trask, J.T. The Special Osprey: Impact on Special Operations Doctrine, June 1996, Thesis presented to School of Advanced Airpower Studies.Google Scholar
4. Whittle, R. Marines want companion for Osprey — A tilt-rotor gunship could be boon for Bell Helicopter, Dallas Morning News, 5 July 2004.Google Scholar
6. Maisel, M.D., Giulianetti, D.J. and Dugan, D.C. The History of the XV-15 Tilt Rotor Research Aircraft: from Concept to Flight, Figs 74, A-12, NASA SP-2000-4517.Google Scholar
7. McVeigh, M.A., Liu, J., O’Toole, S.J. and Woods, S. V-22 Osprey aerodynamic development — a progress review, 1996, Paper 2225, 22nd European Rotorcraft Forum, September 1996, Brighton, UK.Google Scholar
8. Leishman, J.G. and Rosen, K.M. Challenges in the aerodynamic optimization of high-efficiency proprotors, J American Helicopter Soc, 2011, 56, (1), pp 012004-1/21.Google Scholar
9. Burrage, R.G. Studies of a gunship escort concept for the MV-22, 2010, International Powered Lift Conference, October 2010, Philadelphia, PA, USA.Google Scholar
10. Anderson, J.D. Aircraft Performance and Design, 1999, p 217, WCB/McGraw-Hill.Google Scholar
11. Stepniewski, W.Z. and Keys, C.N. Rotary-Wing Aerodynamics, 1984, Dover, Vol I, pp 112/118 and Vol II, pp 151/155.Google Scholar
12. Angle, G., O’Hara, B., Huebsch, W. and Smith, J. Experimental and computational investigation into the use of the Coanda effect on the Bell A821201 airfoil, June 2005, 2004 NASA/ONR Circulation Control Workshop, Part 2, pp 889910.Google Scholar
13. Floros, M.W., Johnson, W. and Scully, M.P. Advanced rotor aerodynamic concepts with application to large rotorcraft, 2002, American Helicopter Society Aerodynamics, Acoustics, and Test and Evaluation Technical Specialists Meeting, 23-25 January 2002, San Francisco, CA, USA.Google Scholar
14. Acree, C.W. Calculation of JVX proprotor performance and comparisons with hover and high-speed test data, 2008, AHS Specialist’s Conference on Aeromechanics, 23-25 January 2008, San Francisco, CA, USA.Google Scholar
15. Prouty, R.W. Helicopter Performance, Stability, and Control, 1986, PWS, pp 41, 52.Google Scholar
16. Johnson, W. Helicopter Theory, 1994, Dover.Google Scholar
17. Quackenbush, T.R. et al. Tiltrotor/tiltwing performance enhancement via active on-blade flaps, 2010, 66th Annual Forum of the AHS, 11-13 May, Phoenix, AZ, USA.Google Scholar
18. Raymer, D.P. Aircraft Design: A Conceptual Approach, 2006, AAIA Education Series, p 347.Google Scholar
19. Leishman, J.G. Principles of Helicopter Aerodynamics, 1st edition, 2000, Cambridge Aerospace Series.Google Scholar
20. Heckles, P. PH School of flying, http://www.paulhecklesrc.co.uk Google Scholar
21. Willington, R. Flight Dynamics Advantages of the Centre-Line Tilt-Rotor Configuration, Spring 2012, Final Year Project Paper, Liverpool University.Google Scholar