航空电子设备 飞行指引仪

20
20
10
10
10
10
20
20
FD command - maintain present heading
Figure 3.2A
Civil Aviation Flight University of China 7
Flight Director Operation
Split Cue Command Bar Operation
NBAA 2003
Commands Satisfied
Pitch Up Roll Left
Pitch RDololwRnight
4
NBAA 2003
Commands Satisfied
Pitch Up Roll Left
Pitch DRoowllnRight
5
Flight Director Operation
Civil Aviation Flight University of China 2
SPLIT CUE COMMAND BAR
Integrated Pitch/Roll Bar
Flight Director Operation
NBAA 2003
20
20
10
10
10
10
20
20
Pitch Up Roll Left
NBAA 2003
When the pilot selects the new heading, the roll command bar will move to the right.
20
20
10
10
10
10
20
20
Selected heading
FD command - roll right
Original heading
ቤተ መጻሕፍቲ ባይዱ
20
20
10
10
Pitch Bar
Roll Bar
10
10
20
20
Pitch Down Roll Right
Aircraft Symbol Horizon
Commands Satisfied
INTEGRATED CUE COMMAND BAR
Aircraft Symbol
Figure 3.1
Civil Aviation Flight University of China 3
Usually, the FD pitch command is limited to +25°/-10°of pitch attitude, while the roll command is limited to about 30°of 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 (F/D)
NBAA 2003
Flight Director
飞行指引仪
Civil Aviation Flight University of China 1
Flight Director Operation
NBAA 2003
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.
Civil Aviation Flight University of China 6
Flight Director Operation
Split Cue Command Bar Operation
NBAA 2003
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.
Figure 3.2B
Civil Aviation Flight University of China 8
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).
NBAA 2003
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.