Abstract
ABSTRACTThe landing period designator (LPD) is primarily a visual aid that provides air and ground crew an unambiguous means of interpreting helicopter and ship safe landing and deck handling conditions. LPD, an application of dynamic interface (DI) studies, was developed to describe in real‐time the responses of an air vehicle to the boundary layer processes during air vehicle launch and recovery. LPD is an attempt to pay greater attention to the dynamic issues encountered by free bodies (air vehicles, for example) on launch and recovery. A review of the tools used to develop the LPD is made. A brief synopsis of the theory and calculation of the ship motion and dynamic interface simulation programs, is presented. The LPD is based on the evaluation of motion bearing energies collapsed into a scalar function called the energy index. The index, an empirical relation, evaluates ship motion as a function of the air vehicle limits by a process of filters designed to determine the air vehicle responses at the instant of recovery. The theory, simulation, and at sea testing programs of the LPD, are summarized. Particular attention is given to LPD responses under especially rigorous at sea pilot‐in‐loop testing conditions. Filter modifications prompted by exposure to extreme environments are discussed. LPD has been found to accurately represent a safe deck in any sea condition. More importantly, LPD has been shown to correctly identify safe deck windows even in the most severe conditions. Application of the LPD as a tool in other DI taskings is considered. In particular, the incorporation of the LPD into NSWC's active operator guidance (AOG) system as a navigational tool is presented. AOG provides the operator with the best ship's heading and speed combination to acquire a desired ship motion risk level within the wind requirements for an aircraft's operations.
Published Version
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