Airplane instrument for furnishing an indicator signal to indicate the necessity for or to control corrective action for offsetting decrease in head wind during landing approach

摘要

1,060,969. Aircraft instruments. SAFE FLIGHT INSTRUMENT CORPORATION. Oct. 2, 1964 [Oct. 16, 1963], No. 40288/64. Heading B7W. [Also in Division Gl] In a device for producing an output signal to indicate an undesirable diminution of headwind during an aircraft's landing approach, or to control automatic apparatus to initiate corrective action, a signal indicative of the airspeed or lift of the craft is modified by a signal indicative of forward deceleration of the craft, although positive forward acceleration has no effect on the output signal. As shown, Fig. 1, an air-speed transducer 12 positions the wiper 68 of a D.C.-energized potentiometer 64 to pick off a potential which is compared with that of the wiper 76 of a reference potentiometer 72 in a first control winding 106 of a magnetic amplifier 20. Forward acceleration is sensed by a pendulum device 18 which positions the wiper 94 of a potentiometer 90; pitch is compensated by a vertical-gyro senser 16 controlling the wiper 86 of a potentiometer 82. Signals indicative of deceleration pass through a second control winding 108 of magnetic amplifier 20, but signals indicative of positive acceleration are shunted through a diode 112 and a series resistor 113. The output signal 104 from the magnetic amplifier is amplified at 114 and fed to indicating or control means 22. Fig. 2 (not shown) depicts a lift senser comprising an angle-ofattack vane controlling a potentiometer to produce a signal which may replace the signal indicative of air-speed. The system may be wholly mechanical.