Abstract: A device is provided for indicating a fluid pressure and flow reversal. The device comprises a float tube in which a float is slideably disposed. An accumulator is disposed in communication with the float tube. The float tube is further in communication with a fluid pressure line. Pressure and flow reversals in the pressure line cause a noticeable movement of the float within the float tube.

Abstract: A compressor air bleed override control system is provided to bleed interstage air from the compressor of an aircraft turbine engine under the conditions during which a compressor instability, such as surge, is likely to occur. The override system includes an override valve control that is in communication with an altitude sensor to make the system operative above a preselected pressure altitude, but inoperative below the selected pressure altitude. The altitude sensor is in communication with the engine fuel control power lever, which is an indirect sensor of compressor speed, such that at speeds corresponding to a slow deceleration from a sufficiently high altitude, the compressor bleed value will rapidly open. The system further measures the rate of movement of the power lever so that small but sufficiently rapid movements of the power lever, which are sustained for a selected period of time, will also cause the compressor bleed valve to open quickly.