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.
Ultrasonic echo ranging techniques and voice synthesis are used to provide a cost-effective convenient means of determining aircraft altitude during the landing phase of flight to overcome parallax problems, thereby to permit proper flare out, while maintaining constant visual contact down the runway during the landing procedure. In one embodiment a visual height indication or audible altitude annunciation is provided by through-the-air sonar ranging, with the display changing or an annunciation made only when the plane descends through predetermined altitudes such as 50, 25, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 feet. In the above embodiment the height is called out by converting a number representing height to a number which is audiblized in a human voice. This height annunciation technique may also be used with microwave range detection apparatus. In various embodiments, the altitude call outs may be periodic, for predetermined changes in altitude, or upon reaching predetermined heights above the runway. A specialized flare out annunciation may also be provided. As an added feature, an apertured focusing tube is used to maintain the transducer contamination to a minimum as is the use of a skeg in front of the open end of the focusing tube to divert air flow and thus contaminants.
A parafoil recovery system capable of autonomously controlling the descent profile of a payload to a recovery area and maneuvering the parafoil to execute a soft landing in the recovery area is disclosed. A descent profile management system determines wind speed and direction, altitude, heading, and position of the payload based on sensor input. The descent profile management system also determines a gliding flight path profile from the launch point to the desired recovery area. A flare and stall maneuver is executed at the end of the landing sequence by braking the parafoil to slow the vertical descent speed and groundspeed for a soft landing. The pitch attitude of the payload can be adjusted by the descent profile management system to prevent nose-first impact with the ground. The parafoil canopy is released from the payload upon touchdown to prevent the canopy from dragging the payload on the ground after landing.
Device for determining the position of an aircraft (11) at an airport, includes a plurality of sensors (5) for detecting at least one radio signal originating from a vehicle (11), in which the plurality of sensors (5) are preferably positioned at regular intervals from one another on parts (2, 3) of the airport which are accessible to the vehicle (11). The present device is preferably used for detecting the position of an aircraft (11) on the runway system of an airport. The sensors (5) are preferably fitted in light positions of runway lighting provided at the airport on taxiways, take-off and landing runways (2, 3) and on plat-forms. The signal originating from a radio altimeter (12) of an aircraft (11) is preferably used as the radio signal.
An aircraft landing information system is disclosed which provides to the aircraft pilot information regarding the actual and preferred sink rate of the aircraft, the distance between the landing gear wheels and the runway, and deviation of the actual sink rate from the preferred sink rate. An altitude determining sensor is provided on the aircraft and the information transmitted therefrom is fed into a microprocessor or like system which then presents the relevant data to the pilot in an audio and/or visual format to allow the pilot to touch down at the preferred sink rate.
A system for use in monitoring, measuring, computing and displaying the Kinetic Energy generated and experienced while aircraft are executing either normal, overweight or hard landing events. Pressure sensors and motion sensors are mounted in relation to each of the landing gear struts to monitor, measure and record the impact loads and aircraft touch-down vertical velocities experienced by landing gear struts, as the aircraft landing gear initially comes into contact with the ground. Velocity adjustments are made to correct for errors caused by landing gear per-charge pressure and landing gear strut seal friction. The system also measures the landing loads experienced by each landing gear strut during the landing event and determines if aircraft limitations have been exceeded.
