Airplane safe take,-off rotation indicator with headwind calculation

Keywords: Safety, Flight safety

In GB Patent 2353511 Safe Flight Instrument Corporation describes a device for indicating that an airplane has reached a safe speed in the presence of headwinds for initiating takeoff rotation. The device senses the true ground speed of the airplane and converts the true ground speed into an "inidicated ground speed" using a coefficient between true air speed and indicated air speed for the airplane, which may be based on ambient air temperature and pressure. The device determines a value relating to headwind from the difference between the indicated ground speed and the indicated air speed of the airplane and,whenever the headwind exceeds a preselected margin, the device increases the value of the safe minimum indicated air speed for initiation of take-off by any excess of the headwind over the preselected margin. The device then directs the flight director to initiate take-off rotation when the indicated air speed of the airplane equals or exceeds the adjusted minimum indicated air speed. The device may utilise clippers and a solenoid or use a computer to process data.