JIC_V1_N1_RP01 K. Thanapalan F. Zhang Journal on Instrumentation & Control Engineering 2321 – 1148 1 1 9 17 Modelling, Stability, Helicopter-Load System This paper describes the mathematical modelling, analysis and simulation study of a helicopter with an external slung load system. The primary feature of the proposed model is the use of a helicopter model that consists of a six-degree of freedom and combined with a three-dimensional motion load model. Considering the two models, a mathematical model for a helicopter carrying an external load is obtained. The combined system model can be used for stability analysis and controller development to improve flight handling quality and system performance. Stability analysis of the system was carried out via simulation. Simulation results revealed that the stability of the helicopter is significantly reduced due to the presence of an underslung load. November 2012 - January 2013 Copyright © 2013 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=2077