Testing and Evaluation of Landing Aids to Improve Helicopter/Ship Operational Limits

The pilot effort involved in a helicopter ship landing is a function of the helicopter flying qualities, the ship airwake and associated turbulence, ship motion, ship visual landing aids, and shipboard obstructions. There are no visual landing aids (VLA) on US Navy surface combatant ships to aid the pilot in anticipating a ship flight deck quiescent period. The Landing Period Designator (LPD) was designed to provide ship motion cues to the pilot to assist him/her in anticipating ship deck quiescent periods that result in acceptable conditions for a shipboard landing. An analytic evaluation of the LPD concept was conducted at the NAVAIR Manned Flight Simulator (MFS) as a build-up prior to at-sea testing. The NAVAIR MFS LPD data were compared to similar data from a RNAS Culdrose UK simulation conducted using similar analytic ship motion conditions. This report summarizes the recorded validating SH-60B / DDG-88 Deck Landing Qualifications (DLQ) exercise data with LPD. The data was recorded on-board USS PREBLE (DDG-88) while transiting from San Diego to Vancouver (BC Canada) March, 2006. As developed in the report, green deck points are identified even in the worst of sea conditions. These periods may be rapid, but owing to the rise time, the deck is constrained to pass from green to red by a latency period. Both the recorded physical data and pilot commentary found LPD to be a useful tool to complete motion sensitive tasks. More importantly, LPD served to demystify the fundamental question of when it is safe to launch and recover. A striking outcome from the DLQ exercise is the validation of the simulated results recorded earlier in the NAVAIR Manned Flight Simulator (MFS). The data further suggested the deck needs to be sufficiently stable for some time after recovery. Once the aircraft is captured, the deck crew would use the LPD as a deck monitor. The limits would be those at which a person would stumble owing to boundary layer conditions.