Although the temperature distributions and infrared characteristics on the helicopter fuselage and in the exhaust plume have been great investigated in previous literatures, most of them are only in hover condition. In order to extend these models to any flight condition, a new integrated methodology is proposed considering the construction coupling and energy transfer relation of the helicopter. In this integrated methodology, we put forward a helicopter model to estimate the flight performance, including required power and attitude of the rotor, and a component-based model of the engine to evaluate the working performance of engines and exhaust plume parameters under various symmetrical steady level flight conditions. After this analysis of coupled working performance, the characteristics of flow and temperature fields are investigated through computational fluid dynamics. Subsequently, infrared radiation characteristics of helicopters are analyzed by a ray tracing method. This work can provide useful information for the energy management design and infrared radiation suppression of helicopters. (C) 2017 Elsevier Ltd. All rights reserved.