Helicopter IRS Engine Integration for the “FIRST” Technology Demonstrator Programme

Abstract

The balanced protection of military assets presents a major challenge to military rotorcraft customers. The proliferation of sophisticated threat systems (including simpler weapons cued by imaging hardware) has highlighted the need for signature suppression systems to be considered as an integral part of rotorcraft design. Suppression of emissions at source offers multiple synergies with other aircraft systems including aerothermal optimisation (minimised pressure losses & highest utility of air flows), enhanced efficiency of other defensive aids equipment, and increased operational effectiveness. The optimisation of the benefits of IR suppression to the helicopter platform as a whole is closely tied into the design of the engine and exhaust system. The achievement of a successful design thus requires the close cooperation of the airframe and engine manufacturers and the availability of the necessary design and assessment tools. This paper is intended to illustrate the many aspects of Infra-Red Suppressor (IRS) design and the tools required to enable successful IRS optimisation and airframe integration. The development of a generic Future Infra-Red Suppressor Technology (FIRST) and the supporting design & analysis capability are described. The FIRST technology development programme has yielded a generic, scaleable, retrofit helicopter IRS that balances aircraft signatures (multi-band IR & RADAR) and installation penalties (such as engine performance and operating costs) to yield a substantial increase in aircraft survivability when compared with existing IRS designs.