Minimum Air wake and Quiescent Motion Indicator Simulator Test Program

A preliminary evaluation is presented concerning anticipated testing results from a real-time shipmotion-based helicopter recovery monitoring system. The method, which is being implemented at the Culdrose Test Centre, gives good performance experimental results with minimal airflow disturbances correlating well with measured quiescent windows of deck motion. The theoretical approach is described concerning wake effects created by structures on the T45 destroyer (air) flight deck using limits appropriate to the approach of a RN MERLIN helicopter. The monitoring system is based on the Landing Period Designator (LPD) energy index, which was integrated into the flight simulator at Culdrose. The system is a reliable means of recording ship motion parameters at the landing deck and in the hangar. A brief synopsis is presented summarising development, simulation and testing of the LPD helicopter recovery aid as applied during the simulator test. The LPD is based on the evaluation of the critical motion parameters collapsed into a scalar function called the Energy Index. The index, an empirical relation, evaluates shipmotion 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. Measurements of instantaneous degree-of-freedom velocity and acceleration are reported, and preliminary comparisons are made with the LPD energy index evaluation during recovery.