On the Airborne Measurement of Vertical Air Velocity

Abstract

The basic design requirements and dynamic performance evaluation techniques are discussed for a vertical air velocity system (VAVS) installed on a Learjet. An empirical technique is presented which compensates the measured angle of attack for the effects of upwash. Flight tests of the VAVS indicated dynamic errors on the order of 0.6 m s?1 plus 3?12% of the aircraft induced vertical velocity during maneuvers where horizontal accelerations were <0.2 m s?2. Substantially larger dynamic errors were seen in the VAVS during maneuvers where the horizontal acceleration exceeded about 0.5 m s?2.