Abstract:
Launch, recovery, and deck handling operations are among the most challenging tasks in the deployment of fleet piloted and unpiloted air vehicles on board of air capable ships. In today's long-lead acquisition process, some existing devices are installed on new ship platforms for which the air vehicle was not initially designed. As part of the Navy deployment process, a ship suitability assessment is conducted in the form of Dynamic Interface (DI) testing. DI testing evaluates all aspects of shipboard helicopter including suitability, compatibility, adequacy, effectiveness, safety of air vehicle shipboard Flying Qualities and Performance (FQ&P), aviation support facilities and procedures for all ship-based aircraft types. With monohulled rudder/screws steered legacy vessels, certain seakeeping and turbulent boundary properties have open-ocean performance similarities. When faced with a deployment target ship producing different ship properties, a systematic approach to adapt to the new environmental condition is devised. A significant example involves the deployment of air vehicles (both piloted and unpiloted) on-board LCS class vessels where large, unexpected roll oscillations, coupling with rapid motions of the stern, are recorded. These unusual deck responses have been traced to shipboard operational characteristics which do not relate to the seaway alone. The implications for air vehicle operations encountering seemingly random large motions further underscores the need for an accurate definition of the ship's dynamics and, possibly, refined models able to predict steep motions anticipating the onset of excessive movements. In this paper we describe a new instrumentation with the goal to predict ship motions conditions with sufficient forecasted time (over a minute) to launch, recover and complete other motion sensitive tasks regardless of the seaway. The fundamental concept is to measure remote sea surface profiles to predict the future wave forces acting upon a vessel as a function of the approaching air vehicle. The final objective is to expand ship operating deck limits to approximately Sea State 6+. This will allow the air's vehicle operator to have a more complete deck information and ship behavior. This article describes the common test procedures being developed at Fincantieri to define the deck behavior with the least air vehicle modifications. Enhanced dynamic interface testing is designed to better understand how the new ship classes affect the deck environment. The enhanced trial methodology test results clearly characterize essential aspects of the ship responses to the maritime climate and its impacts on air vehicle launch and recovery.