This procedure applies to engine or airframe-mounted fuel pumps. The procedure recommends single-pass operation to minimize changes in fuel properties affecting NPSP capability. An optional method using a recirculation system is also included and may be specified at the discretion of the equipment specification. This procedure defines the recommended test setup@ test procedure@ data acquisition@ and data presentation. Purpose: This SAE Aerospace Recommended Practice (ARP) defines standard procedures to conduct tests and evaluations of aircraft and engine fuel pumps for the purpose of determining NPSP performance capability. NPSP = Total pressure - TVP (Eq.1) NPSP = ( P static + P Dynamic) - TVP (Eq.2) The procedure recommended herein is intended to produce useful@ reproducible results at steady state conditions. This test is not intended to establish altitude@ climb rate@ starting@ or other transient performance of the article being tested for a specific aircraft installation. This test does address interstage or discharge heat input from the engine in addition to heat generated by the pump itself. This is common to modern engine fuel systems and can significantly influence NPSP capability. This is especially true at high turn down conditions as described in 3.1.1. NOTE: At high flow conditions where metalconditions is negligible where compared to flow capability to remove heat@ interstage or discharge heat may not be required since inlet pump elements are unaffected. Prior testing with temperature measured directly at the pump inlet may be required to determine the influence of this heat addition.