Experiences with the Landing Period Designator (LPD) Helicopter Recovery Aid in High Sea States

Experience with the Landing Period Designator (LPD) helicopter recovery aid in various sea states up to severe, hurricane conditions are discussed. Operational improvements, as shown by helicopter/pilot performance are presented together with an evaluation of a prototype LPD display leading to the development of a production NVG compatible light indicator. LPD is a helicopter recovery aid designed to display helicopter operational limits as a function of ship motion, to the pilot and ship operators. The device complements wind oriented launch and recovery charts with realtime evaluation of the ship oriented forces the helicopter will encounter. Theory and technical descriptions are presented. Recovery time and deck status was recorded for all sea conditions. Pilot evaluations indicate that LPD improves confidence by consistently indicating safe landing periods in all sea conditions. Even though air operations were canceled above sea state 6, LPD continued to operate through Hurricane Lili, with only minor fluctuations during the most extreme conditions.