Runway and obstacle detector to improve airplane landing

• US 4,302,827 A
• Filed: 04/08/1980
• Issued: 11/24/1981
• Est. Priority Date: 04/08/1980
• Status: Expired due to Term

• Current Assignee: Arthur B. Rosenblum
• Original Assignee: Arthur B. Rosenblum
• Inventors: Rosenblum, Arthur B.
• Primary Examiner(s): Farley, Richard A.
• Application Number:
  US06/138,645
• Time in Patent Office: 595 Days
• Field of Search: 367/114, 367/116, 367/909, 367/902, 340/27 R, 340/27 AT, 343/5 LS
• US Class Current: 367/116
• CPC Class Codes: G01S 15/88 Sonar systems specially adapted for specific applications seismic or acoustic prospecting or detecting G01V1/00

Abstract

An airplane flies through the air because the forward speed of its wings through the air produces lift which is greater than the total weight of the craft. When the forward speed decreases below a certain amount, there is insufficient lift to counteract the weight of the plane and the plane will drop down (or stall). This is the ideal condition of speed at which an airplane lands, but it is important that the stall occur when the plane is only a very short distance (like three feet) above the ground. It is also very important that the plane remain well above the ground or other obstacles until a suitable landing field is reached.

The device herein described uses "sonar" or reflections of sound pulses to give the pilot an audible indication of his exact distance from the ground so that he can know the correct moment to stall or "flare" the plane for a perfect landing. The device also warns of obstacles when they are less than 100 feet below the aircraft to warn the pilot if he is flying too low before reaching the airport.

Claims

1. An apparatus for a pilot controlled airplane comprising an ultrasonic pulse transmitter;

ultrasonic echo detecting means including time measuring means for measuring the interval between a transmitted pulse and its echo;

converting means for transforming the measured interval into an altitude signal within a range from one foot to about one hundred feet;

means for converting said altitude signal into a variable pitch tone signal in the audible range;

a tone generator for producing an intermittent flare tone signal;

means providing the pilot with the variable pitch signal and the flare tone signal for indicating the desired flaring altitude; and

means for mounting the ultrasonic pulse transmitter and echo detecting means so that the ultrasonic pulses are reflected from the revolving propeller tips, thereby generating an intermittent change in the variable pitch tone signal, thus assuring the pilot that the altitude measuring system is operative.