The Pitot-Static Evaluation Exercise is one of the first flight exercises conducted as part of the rotary wing syllabus at the U.S. Naval Test Pilot School. The purpose of the exercise is to introduce the basics of flight test through an evaluation of a helicopter pitot-static system, which provides pilots with information about the helicopter’s airspeed and altitude by measuring total and static air pressure.
The exercise is designed to confirm the calibration of the aircraft’s built-in instruments in various modes of flight, such as climbs, descents and turns. Pitot-static systems can be affected by many variables such as the flight path, rotor downwash and external stores. Carrying a pitot-static system at the end of a trailing line that extends beyond the rotor downwash eliminates many of these localized effects.
A typical evaluation exercise sortie consists of two aircraft, with the lead aircraft carrying a trailing pitot-static device on a 125-foot cable attached to its cargo hook fitting. The safety chase aircraft verifies cable clearance from the underside of the aircraft and rotors during a variety of flight profiles.
Over the years, the school has used a variety of helicopters to conduct the sortie. It most recently transitioned from the OH-58 Kiowa to the UH-60A+ Blackhawk. To further maximize scheduling efficiency and availability, the school recently obtained a flight clearance to install the trailing device system on its five UH-72A Lakotas.
The first sortie of the trailing pitot-static device on a UH-72A Lakota took place Oct. 15 at NAS Patuxent River. The engineers, ground crew, instrumentation team and aircrew worked together to safely achieve the first flight objective to verify the flight profiles were suitable for instruction. Subsequent student sorties have been flown which allow them to develop their understanding of pitot-static theory, identify risks specific to flight operations with a trailing pitot-static device and perform data collection techniques during engineering test flights.