航空电子设备-飞行指引仪..ppt

1NBAA 2003 Civil Aviation Flight University of China Flight Director 飞行指引仪Flight Director (F/D)2NBAA 2003 Civil Aviation Flight University of China The principle of the flight director is that the pilot programmes the system by selecting a mode, such as an ILS approach, and the computer would assess the difference between what the aircraft was doing, and what the pilot wanted it to do, e.g. intercept (capture) the localizer and glidepath. The computer would then tell the pilot what to do in the form of pitch commands and roll commands. Pitch and roll guidance is presented on the attitude indicator in the form of command bars. These can either be a system of two separate bars at right angles (split cue), which present pitch and roll commands separately, or an inverted V-bar which presents combined pitch and roll commands (integrated cue). Flight Director Operation3NBAA 2003 Civil Aviation Flight University of China Flight Director OperationFigure 3.14NBAA 2003 Pitch Up Roll LeftPitch Down Roll RightCommands Satisfied5NBAA 2003 Pitch Up Roll LeftPitch Down Roll RightCommands Satisfied6NBAA 2003 Civil Aviation Flight University of China There are no deviation scales for command bar movement, but the further the command bar is from the center position, the greater the correcting input must be; small command bar deviations from the aircraft symbol only require small corrections to attitude. Usually, the FD pitch command is limited to +25/-10of pitch attitude, while the roll command is limited to about 30of bank. In manual flight, the FD provides flight attitude commands for the same modes as the autopilot, although the bank angles and capture protocols may be slightly different.Flight Director Operation7NBAA 2003 Civil Aviation Flight University of China Figure 3.2AFlight Director Operation To explain the operation of the roll command bar, consider a right turn to a pre-selected heading. The pitch command bar has been removed for clarity. Split Cue Command Bar Operation8NBAA 2003 Civil Aviation Flight University of China Figure 3.2BFlight Director Operation When the pilot selects the new heading, the roll command bar will move to the right. Split Cue Command Bar Operation9NBAA 2003 Civil Aviation Flight University of China Figure 3.2CFlight Director Operation As the pilot rolls to the right, the roll command bar will move towards the center position. The roll command bar centers when the flight director computer is satisfied with the bank angle. The roll command bar will remain in the zero position while the steady state turn continues.Split Cue Command Bar Operation10NBAA 2003 Civil Aviation Flight University of China Figure 3.2DFlight Director Operation As the selected heading is approached, the roll bar moves to command a roll to the left, i.e. to reduce the bank angle.Split Cue Command Bar Operation11NBAA 2003 Civil Aviation Flight University of China Figure 3.2EFlight Director Operation As the pilot rolls left, reducing the bank angle, the command bar will center. Following the guidance given by the command bar, the aircraft will roll out wings-level on the new heading.Split Cue Command Bar Operation12NBAA 2003 Civil Aviation Flight University of China Figure 3.2FFlight Director Operation The pitch bar responds in a similar manner to the roll bar, centering when the pitch command is satisfied. The pitch command bar is horizontal and moves vertically in relation to the aircraft symbol on the attitude director indicator. A movement of the pitch command bar below the aircraft symbol calls for a nose-down attitude change, and a movement above the aircraft symbol calls for a nose-up attitude change. Split Cue Command Bar OperationFigure 3.2G13NBAA 2003 Civil Aviation Flight University of China Flight Director Operation With the integrated cue system, a movement of the V-bars above the aircraft symbol calls for a nose-up attitude change. A left roll movement of the V-bars relative to the aircraft symbol is commanding a left roll input. Note that the V-bars do not move from side to side, they can only roll left and right relative to the aircraft symbol. Flying the aircraft to tuck the aircraft symbol into the V-bars will satisfy the FD computer.Integrated Cue Operation14NBAA 2003Flight Director Control Panel15NBAA 2003 Civil Aviation Flight University of China Pitch Selector The pitch selector allows the pilot to set the desired pitch attitude, usually between 10 nose DOWN and 15 nose UP, by rotating the knob. Once selected, the bars will command the pitch attitude adjustments needed to achieve and maintain the desired pitch angle. The roll bar will command wings level, until a navigation mode is selected.Flight Director Control PanelFigure 3.316NBAA 2003 Civil Aviation Flight University of China Mode Selector OFF. The OFF position turns the flight director off and removes the command bars from view.HDG. The heading mode is used to hold the selected heading set by the heading bug on the HSI. VOR/LOC. The VOR/LOC m。