DE3014323A1 - Flight computer for aircraft pilot - obtains max. fuel economy by monitoring sensors for air speed and fuel consumption rate - Google Patents

Abstract

The flight computer uses a velocity signal and a fuel consumption rate signal to provide the pilot or the autopilot control with a flight value corresp. to max. fuel economy. Pref. the computer uses a microprocessor and associated integrated circuit modules corresp. to the lay-out of the aircraft instruments. It has a main panel comprising the microprocessor and its digital peripheries, a second panel with input/output connections for the sensors and the display system and current supply module which can be switched for connection to a 12 volt or 30 volt supply. The sensors comprise a differential pressure sensor, an absolute pressure sensor, a total temp. sensor and a fuel consumption rate sensor.

Description

This # denotes a device that the pilot

of an aircraft gives the possibility with the help of its control variables an optimal or partially optimal flight condition in terms of maximum range to adjust.

It is a self-sufficient, highly integrated unit that has a microprocessor as its core.

It is primarily intended as a supplement to the existing cockpit systems.

The following paragraphs briefly cover the structure and work received with this device.

STRUCTURE The device is designed as a single-block device using plug-in module technology and corresponds with the width of 146 mm and the height of 47.5 mm in its front panel dimensions the international ARINC standard for avionics built-in devices.

The entire electronics are built on three plug-in boards: - Main board 1: with the processor and its digital peripherals - main board 2: input / output for sensors and display systems - Stromversorgungsmqdui With this system classification the highest level of service friendliness was achieved.

The power supply module was designed for any input voltage rated between 12 and 30 volts.

FUNCTION The following sensors supply the microprocessor via A / D converter Measured values: - differential pressure sensor; this sensor delivers proportional to the difference between total pressure 'Pitot tube connection) and static pressure (connection to static boreholes of the aircraft) an analog signal which is a measure for the IAS (Indicated Airspeed) is.

- Absolute pressure sensoro this transducer delivers proportional to the static pressure and thus an analog signal for the flight altitude.

- Total temperature sensor: it also provides an analog output signal, which is proportional to the air temperature. This is a special one sensitive transducer; this results in a measurement that is as delay-free as possible the ambient temperature of the moving aircraft.

- Flow meter: a special sensor was developed here, which has been adapted to the requirements of the overall system.

The main features of this sensor are: - small dimensions - high accuracy - very low temperature dependence - very high resolution - low hysteresis - short response time - no impairment of the fuel flow in the event of failure after When the device is switched on, the microprocessor continuously queries the measured values from the sensors and the setting values of the two coding switches and essentially calculates from them the true airspeed and the quotient of this and the fuel consumption. Furthermore, the corrected altitude and the remaining fuel are determined and displayed.

The fuel flow is digitally linearized and also displayed All displays are of a bright and energy-saving LCD design.

OPERATION AND DISPLAY MODES Before the aircraft takes off, the Pilot switch on the device and check the current QNH value and the usable amount of fuel snap into place. If the aircraft has not been refueled, there is no need to set the Amount of fuel, since the remaining amount of the last flight is saved.

If the OFC is only switched on during the flight, the remaining amount is in the tank from the on-board fuel gauges, if an absolute one Display of remaining quantities is required.

For cross-country flights, the QNH value is the respective local air pressure adapt.

The extreme value display is independent of the above-mentioned entries active immediately after each switch-on.

During the flight the pilot has the following data at his disposal Available: - TAS - (True Airspeed) display This only provides an exact one Value if the QNH value corresponds to the local air pressure conditions.

With QFE or the standard setting, the error is a maximum of 1 - 2% - Altitude display This indicates the altitude above MSL if the local QNH value is set will. If the QFE value is locked, then Xie height above ground is available.

With a setting of 1013 mb, the flight level is displayed.

This setting method is completely identical to that of a conventional one Altimeter. ~ - Fuel Consumption This is a calibrated display of the current consumed fuel volume shown per unit of time.

The dimension is liters / h, i.e. the pilot can still use it the standing fuel volume to conclude the maximum flight time.

- Fuel gauge With this a very precise value of the still flyable fuel volume made available.

- Extreme value display This display is the core of the OFC it is calibrated in kilometers of flight distance per liter of fuel ".

This gives the pilot the opportunity to optimally adjust the flight status. Some examples of these setting options are explained in the next paragraph. When there is no wind, you can use the fuel gauge to determine the range.

WORKING WITH THE EXTREME VALUE DISPLAY The options for setting, which open up with the extreme value display are on a light aircraft with a piston engine explained. In principle, this system can be used for every aircraft.

It is known from flight mechanics that there is an airspeed for every aircraft with which you can achieve maximum range. This speed is in the Practice, however, so small that the associated specific fuel consumption due to the low power is very high.

This results in an optimal cruising speed in general is much higher.

To fly this, the pilot simply takes the throttle lever back until the extreme value display shows a maximum value. The read The number shows the flight distance per liter of fuel that can be achieved with this setting relative to the air mass, If there is no wind, this corresponds then the flight distance per liter of fuel over the ground.

If a propeller adjustment is available, a combination of this and the throttle position.

These settings generally lead to a longer range than the ones suggested in the manual as they both the condition of the engine and the of the cell.

A further increase in the extreme value is achieved through precise setting of the fuel mixture lever reached. This method is identical to the setting according to the maximum exhaust gas temperature.

To fly relative maxima - this is necessary, for example, when the pilot compromises between high cruising speed and optimal Want to close profitability - is primarily the desired one with the throttle lever Travel performance and then with the help of the extreme value display the propeller position and adjust the fuel mixture for optimum economy.

Claims (1)

OPTIMAL FLIGHT CALCULATOR Patent claims: The claims relate to a device, which is characterized in that it uses the speed signal and the fuel flow signal determines a value which the pilot or Autopilot of an aircraft the possibility gives an optimal flight condition adjust with regard to economic efficiency.