航空電子設(shè)備-飛行指引儀

1、 Civil Aviation Flight University of China Flight Director 飛行指引儀Flight Director (F/D) 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 betw

2、een 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

3、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 Operation Civil Aviation Flight University of China Fl

4、ight Director OperationFigure 3.1 Pitch Up Roll LeftPitch Down Roll RightCommands Satisfied Pitch Up Roll LeftPitch Down Roll RightCommands Satisfied 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 p

5、osition, 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 pr

6、ovides flight attitude commands for the same modes as the autopilot, although the bank angles and capture protocols may be slightly different.Flight Director Operation Civil Aviation Flight University of China Figure 3.2AFlight Director Operation To explain the operation of the roll command bar, con

7、sider a right turn to a pre-selected heading. The pitch command bar has been removed for clarity. Split Cue Command Bar Operation 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

8、Cue Command Bar Operation 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 r

9、oll command bar will remain in the zero position while the steady state turn continues.Split Cue Command Bar Operation 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 reduc

10、e the bank angle.Split Cue Command Bar Operation 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 th

11、e new heading.Split Cue Command Bar Operation 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

12、 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 3.2G Civil Aviation Fli

13、ght 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 mo

14、ve 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 OperationFlight Director Control Panel Civil Aviation Flight University of China Pitch Selector The pit

15、ch 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

16、a navigation mode is selected.Flight Director Control PanelFigure 3.3 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 o

17、n the HSI. VOR/LOC. The VOR/LOC mode slaves the bank function of the command bars to the VOR radial set on a HSI, or to the localizer path of a tuned ILS localizer. Flight Director Control Panel Civil Aviation Flight University of China Mode SelectorAPP AUTO. Selection of approach automatic commands

18、 the roll function of the command bars to maintain the present intercept mode (heading or VOR radial tracking), and to capture and maintain the localizer course. APP MAN. Selection of approach manual commands an immediate capture of localizer and glidepath, overriding any current roll or pitch modes

19、.Flight Director Control Panel Civil Aviation Flight University of China Mode SelectorGA. When GA (go-around) is selected, the FD will command a pre-programmed go-around pitch attitude, typically 15nose-up (or 13nose-up, engine-out) with wings level. More modern systems normally have the GA function of the FD activated by pressing a button on one of the power levers.Flight Director Control Panel Civil Aviation F