2. Integrated Flight Instrument Systems Flashcards
Aautomatic Flight Control System
Consists of
- autopilot flight director system (AFDS)
- AUTO THROTTLE SYSTEM (A/T)
REMOTE CONTROL PANEL, AND FLIGHT MANAGEMENT COMPUTER CONTROL AFDS AND AUTO THROTTLE SYSTEM
Autopilot flight director system (AFDS)
Consists of
- three autopilot flight director computers (AFDCs)
- the MCP
Flight director
Either inverted chevron, known as integrated cue command bars.
Some aircraft use crossed bars, known as split cue command bars.
Flight director components (8)
- Mode select panel
- Computer
- Attitude direction indicator
- Horizontal situation indicator
- NAV receiver
- VERTICAL GYRO
- Amplifier unit
- Magnetic compass unit
HSI modes
Expanded map mode centre map mode, Expanded VOR/ APPROACH MODE Centre VOR/ Approach mode Plan mode
Auto throttle modes
THR- AUTO THROTTLE APPLY THRUST TO MAINTAIN THE VERTICAL SPEED REQUIRED BY PITCH MODE
THR REF- thrusters sit to the selected thrust limit displayed on EICAS.
IDLE- displayed while auto throttle moves the thrust leaders to idle. Idle mode is followed by hold mode.
HOLD- auto throttle servos are inhibited. Pilot sets thrust manually.
SPD- AUTO THROTTLE MAINTAINS SELECTED SPEED ON THE PFD.
Auto throttle stall support
Can support stall protection when armed and not activated. If speed decreases to near stick shaker activation, auto throttle automatically activates in the appropriate mode. Advances thrust to maintain minimum maneuvering speed. EICAS message AIRSPEED LOW displays.
DURING A DESCENT IN VNAV SPD, auto throttle may activate in HOLD mode and will not support stall protection.
Auto throttle disconnect automatically when
- A fault in the active auto throttle mode is detected
- either reverse thrust lever is raised to reverse idle
- thrust levers are overridden during a manual landing, after the auto throttle has begun to retard thrust levers to idle.
- when both engines are shut down
Flight mode annunciator
FMA.
Function is to alert the pilot to what the current status of the autopilot flight director system AFDS is
Flight MODE annunciator
1A. Auto throttle status- N1
1B. Roll status
1C. Pitch status
Expanded localizer indications
Displays when autopilot or flight director is in LOC mode And aircraft is closed to runway centerline. Provides a more sensitive display in final critical phase of flight.
Rectangle equals 1/2 dot deviation.
Also called GAIN program
Charted temperature limitations- VNAV
Barometric ALTIMETERS calibrated to indicate altitude in ISA conditions. WHEN TEMPERATURES HOTTER THAN ISA, true altitude will be higher than altitude indicated by altimeter.
Conversely, when temperature is lower than isa, true altitude will be lower than indicated.
Remember- temperature gradient from sea level is greater in cooler air, therefore pressure drops off faster.
High to low- watch out below..
Procedure altitudes often raised to compensate for colder climates!
LNAV intercept
On any heading and within 3 nautical miles of active route segment. If outside of three nautical miles a plane must be on an intercept course of 90° or less and intercept the route segment before the active waypoint
Autoland
Fail-passive system (Land 2)
Following system failure, no out of trim condition. requires at least two autopilots to be engaged in the autoland mode.
Fail-operational system (Land 3)
In the event of a failure below alert height, the approach, flare, landing can still be completed by the remaining part of the automatic system. If system fails, simply reverts to being fail passive system. To be fail operational, three or more independent autopilot channels must be engaged for autoland.
Land 1- only one autopilot is engaged. Autoland cannot be completed.
Automatic trim system
Transfers trim from elevators to the stabilizers. Trimmable stabilizer does not move in response to control column movement.
