Joined: 11 Dec 2005
|Posted: Mon Aug 06, 2012 3:49 am Post subject: Flight Instruments (Technical Notes)
|Localizer Pointer and Scale
Scale turns amber and the pointer flashes:
To indicate excessive localizer deviation (at low radio altitudes (below 500 RA), with the autopilot or flight director engaged).
To indicate that the localizer is not captured (at low altitudes (below 1000 RA), with LNAV engaged and LOC armed).
Glideslope Pointer and Scale
Scale turns amber and the pointer flashes:
To indicate excessive glideslope deviation (at low radio altitudes (below 500 RA), with the autopilot or flight director engaged).
Autopilot/Flight Director Barometric Source
L or R indicates that the left or right EFIS control panel is the barometric setting reference for the autopilot or flight director (the same indication is displayed on both PFDs).
Displayed when a flight director switch is ON or the autopilot is engaged.
F/D one turned on and one not on determines L or R
F/D both on L is displayed
A/P first one pushed on determines L or R.
Maximum Speed and Maximum Maneuvering Speed
RED: Indicates maximum permissible airspeed as limited by the lowest of the following:
Landing gear placard speed, or
Flap placard speed.
AMBER: When displayed, indicates maneuver margin to high speed buffet. Bottom of the bar is the airspeed that provides 1.3 g maneuver capability (or an alternative approved maneuver capability as preset by maintenance). Bar may be displayed when operating at high altitude at relatively high gross weights (1.3 g maneuver capability = 40 degrees bank capability in level flight)
Minimum Speed and Minimum Maneuvering Speed
RED: Indicates the airspeed where stick shaker activates.
AMBER: Indicates maneuver speed margin to stick shaker or low speed buffet. Top of the bar is the airspeed that provides:
1.3 g maneuver capability to stick shaker with flaps down.
1.3 g maneuver capability to stick shaker or VREF + 80, whichever is less, with flaps up below 20,200 FT.
1.3 g maneuver capability to low speed buffet (or an alternative approved maneuver capability as preset by maintenance), with flaps up above 20,200 FT.
Displayed with first flap retraction after takeoff (1.3 g maneuver capability = 40 degrees bank capability in level flight)
Stall Speed, Warning & Limitations on Maneuvering Flight
Weather radar and TCAS are not displayed in:
CTR APP mode
CTR VOR mode
Basically not avaialble in all the CTR modes except MAP mode
WXR turns the weather radar on and off, and displays weather radar information.
- displays high and low altitude navigation aids, if the ND range selector is in the 10, 20 or 40 NM range
- displays high altitude navigation aids, if the ND range selector is in the 80, 160, 320, or 640 NM range.
WPT displays waypoints, if the ND range selector is in the 10, 20 or 40 NM range.
- displays ADIRU and GPS positions
- displays VOR raw data radials extended from the nose of the airplane to the stations displayed on the CDU NAV RAD page.
Instrument Source Select Panels
Navigation (NAV) Source Switch
OFF - (Normal Position) with the FMC selector in AUTO, the active FMC provides the information to generate the ND map. If both FMCs fail, the CDU provides navigation data.
CDU - (Non-Normal Position) The selected CDU generates the ND map. Normally the sources are: left ND map left CDU and right ND map right CDU.
Air Data / Attitude (AIR DATA/ATT) Source Switch
OFF (normal position). ADIRU (Air Data Inertial Reference Unit) provides air data and attitude information to the PFD and ND. Alternate sources or the SAARU (Secondary Attitude Air Data Reference Unit) are automatically selected to replace ADIRU air data or attitude, as required.
ALTN (nonnormal position). The PFD and ND alternate air data/attitude source is selected as follows:
air data (captain): SAARU single channel
air data (first officer): ADIRU single channel
attitude (captain and first officer): SAARU.
Display Control (DSPL CTRL) Source Switch
OFF (normal position). Automatically selects display processing channels for the outboard and inboard (left/right) display pairs. Reconfigures display processing channels as required for display unit or processing channel failures.
ALTN (nonnormal position) An alternate display processing channel is selected to replace the current display processing channel.
Center Display Control (DSPL CTRL) Source Switch
Same as the display control source switches for the left and right inboard and outboard display units, except this switch controls the upper center and lower center display units.
Heading Reference (HDG REF) Switch
NORM: Normally references magnetic north
automatically references true north when north of 82°N or south of 82°S latitude or within the vicinity of the magnetic poles (PFDs, NDs, and FMCs).
provides no reference for AFDS roll modes other than LNAV when north of 82°N or south of 82°S latitude or in the vicinity of the magnetic poles.
TRUE: References true north regardless of latitude.
When the AFDS roll mode is HDG SEL (or TRK SEL), switching the heading reference switch from NORM to TRUE or TRUE to NORM engages the HDG HOLD (or TRK HOLD) mode.
Grid Heading is displayed on ND above 70 deg latitude
Display Select Panel
Pushing the switch displays the associated display. Pushing the same switch a second time blanks the display or (left and right inboard display units) redisplays the ND if there is only one page of messages. If there are more than one page of messages, pushing STAT pages through the messages.
STAT status page:
hydraulic system indications
oxygen system indications
status messages for dispatch determination
Integrated Standby Flight Display
Attitude Reset (ATT RST) Switch:
Push and hold at least two seconds -
aligns horizon with the airplane symbol
reset takes approximately ten seconds
starts new initialization sequence if previous attempt failed (ground only).
Air Data Inertial Reference System (ADIRS)
The ADIRS provides:
primary, secondary and standby air data
inertial reference information.
The major components of the ADIRS are:
one air data inertial reference unit (ADIRU): It is the primary source for speed, altitude, attitude and inertial navigation position information.
one secondary attitude air data reference unit (SAARU): It is the secondary source for speed, altitude, and attitude information. It does not provide navigational position data.
eight air data modules
six static ports
three pitot probes
two angleofattack vanes
one total air temperature probe.
Non-Normal Checklist Icon
EICAS alert messages with associated incomplete or unaccessed checklist procedures are displayed with an icon (a white, empty box) to the left of the message. The icon indicates checklist status.
- the checklist for the displayed message has not been accessed
- or the checklist has incomplete steps
Icon not displayed:
all checklist steps are complete
- there is no checklist procedure for the displayed message
- or another message is displayed whose corresponding checklist inhibits display of the icon