Dynamic and Aerodynamic Clearance of the Apache AH Mk1 Attack Helicopter for Embarked Operations

Abstract

Abstract

The introduction into service of the Westland manufactured Apache AH Mk1 has coincided with a thrust within the UK armed services for a greater emphasis on amphibious operations within the littoral environment. From this background has emerged a requirement for an embarked, attack helicopter capability, for which the Apache AH Mk1 has been earmarked. However, this helicopter being, by design, optimized for the battlefield environment, cannot be presumed to adapt to the naval environment without presenting certain challenges. This article describes how Westland Helicopters Ltd has sought to determine the feasibility of conducting embarked operations with Apache AH Mk1 by deriving limits to be respected during Ship Helicopter Operating Limits (SHOL) trials using a variety of analytical methods. Aspects of operation considered include aircraft lashing, landing, stability on deck with rotors running or stationary and when being towed, rotor engagement and disengagement, ground resonance, and main rotor spreading and folding. The article considers further aspects of importance to embarked operations and summarizes the trials process that results in an operational envelope for service use. It concludes that a practical operating envelope can be achieved, anticipates a successful outcome for the SHOL trials, and includes a projection for future activities to enhance the aircraft's maritime operational capabilities.