FMC Messages Flashcards
CRZ ALT CHANGED TO XXXXX
U10.5 and later
CLEAR THE MESSAGE. VERIFY MCP CRUISE ALTITUDE. Cause - An altitude constraint added due to entering a new company route, a new destination airport, or selection of a new procedure conflicts with the cruise altitude, resulting in automatically raising the cruise altitude to match the highest waypoint altitude constraint in the mod plan, when not in active descent.
CHECK ALT TGT
U10.5 and later
CLEAR THE MESSAGE. Cause - VNAV disengages while airplane is between MCP and FMC altitudes or VNAV button pressed while airplane is between MCP and FMC altitudes.
CUTBACK DISARMED
U10.6 and later
CLEAR THE MESSAGE. RE-ARM AS REQUIRED. Cause - Cutback turned off as a result of changing or deleting the flight plan runway while on the ground.
CUTBACK UNAVAILABLE
U10.3 and later
CLEAR THE MESSAGE. Cause - The FMC is unable to compute a Cutback N1 value.
CYCLE IRS OFF–NAV
CYCLE IRS MODE SELECTOR TO “OFF” AND BACK TO “NAV.” Cause - IRS is unable to complete alignment under current conditions.
DATA BASE INVALID
ADVISE MAINTENANCE PERSONNEL TO CHECK THE FMC AND RELOAD THE DATABASE, AS REQUIRED. IF DESIRED, CONSIDER THE USE OF THE TEMPORARY NAV DATABASE. Cause - The automatic validity test of the permanent navigation database has failed.
DISCO INSRTD AFTR
XXXXX (waypoint identifier)
SELECT THE RTE OR RTE LEGS PAGES AND MODIFY THE WAYPOINTS FOR A CONTINUOUS ROUTE. Cause - A ROUTE DISCONTINUITY has
been inserted into the flight plan due to undefined termination of a downpath leg or a triple waypoint BYPASS.
DISCONTINUITY
SELECT THE RTE LEGS PAGE. ENTER THE DESIRED ACTIVE WAYPOINT INTO THE BOX PROMPTS. CORRECT ANY ROUTE DISCONTINUITY AND
EXECUTE. REENGAGE LNAV. Cause - Passing the last waypoint in the route prior to a ROUTE DISCONTINUITY
(LNAV disengages) or pressing LNAV while in a discontinuity.
DRAG REQ AFTER XXXXX
U10.7 and later
MODIFY FLIGHT PLAN AS REQUIRED.
CLEAR THE MESSAGE. Cause - A waypoint speed constraint greater than 10 knots above the predicted speed exists at waypoint XXXXX.
END OF OFFSET
CONFIRM CLEARANCE. Cause - Two minutes prior to passing offset leg termination.
END OF ROUTE
SELECT THE RTE LEGS PAGE. ENTER THE DESIRED ACTIVE WAYPOINT INTO THE DASH PROMPTS AND EXECUTE. REENGAGE LNAV. Cause - LNAV engaged and passing the last waypoint in the route (LNAV disengages).
ENG OUT SID MOD
U10.3 and later
CLEAR THE MESSAGE. Cause - An engine–out SID has been automatically inserted into the flight plan as a modification.
ENTER IRS POSITION
ENTER IRS PRESENT POSITION INTO THE SCRATCHPAD PAD AND LINE SELECT 4R ON THE POS INIT PAGE OF THE CDU. IF PRESENT POSITION WAS PREVIOUSLY ENTERED, OVERWRITE DISPLAYED DATA. IF NECESSARY, ENTER PRESENT POSITION DIRECTLY INTO THE IRS CONTROL
/DISPLAY UNIT. Cause - IRS in the alignment mode needs present position to complete alignment. Previous present position entry was not received back from the IRS.
FMC APP/TUNE DISAGREE
U10.5 and later
CONFIRM THE TUNED FREQUENCY AND APPROACH SELECTED IN THE FMC ARE BOTH CONSISTENT WITH THE ACTUAL APPROACH INTENDED TO BE FLOWN. RESOLVE TUNING OR APPROACH SELECTION INCONSISTENCY. CLEAR THE MESSAGE. Cause - An approach that utilizes FMC generated glide path is in the active flight plan but an approach navaid (ILS/GLS) has been tuned with G/S ON.
FMC DISAGREE
U10.8 and later
MONITOR FMCS CLOSELY. BOTH FMCS REMAIN ONLINE. LIMIT APPROACHES TO SINGLE FMC ONLY. IF DESIRED, REVERT TO SINGLE FMC
OPERATION IN THIS SECTION. Cause - During approach or on the ground, monitored parameters required for dual FMC operation are in disagreement. (Dual FMC as installed) Message will remain displayed until the condition has been resolved. The FMC does not check for mach and indicated air speed miscompares on the ground.
FMC DISAGREE - VERTICAL
U10.8A and later
DO NOT MOVE THE FMC SOURCE SELECT SWITCH. MONITOR CROSSING ALTITUDES TO ENSURE COMPLIANCE. Cause - A vertical deviation, FMC Airspeed, or FMC Mach value disagreement between the FMCs by more than the allowed tolerance occurs and long enough that all attempts to resynchronize failed while the aircraft is in a path descent. Message display is inhibited when in the Approach Nav environment. (dual FMC as installed)
FMC POS/RW DISAGREE
U10.7 and later
REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE. Cause - Position information is contradictory.
GPS-L INVALID GPS-R INVALID
U10.7 and later
CLEAR THE MESSAGE.
FOR ADS-B OPERATIONS (IF INSTALLED), WHEN ONE GPS IS INVALID, ENSURE THAT THE TRANSPONDER SELECTOR IS POSITIONED TO THE SIDE WITH THE VALID GPS.
FOR DUAL GPS INSTALLATIONS, IF BOTH GPS-L INVALID AND GPS-R INVALID
MESSAGES SHOW, REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE.
FOR SINGLE GPS INSTALLATIONS, REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE Cause - FMC is no longer receiving valid information from the displayed GPS system.
INSUFFICIENT FUEL
U13.0 and later
MODIFY THE ROUTE PLAN OR CRUISING ALTITUDE, OR DIVERT FOR ADDITIONAL FUEL. Cause - FMC fuel at the destination is predicted to be less than 2000 lbs/900 kilograms.
Scratchpad message shows for Active and Mod Flight Plan.
Illuminates the FMC P/RST Light for Active and Mod Flight Plan.
IRS MOTION
CLEAR MESSAGE AND ATTEMPT TO REDUCE AIRPLANE MOVEMENT, IF PRACTICABLE. Cause - IRS has automatically restarted the alignment due to detection of excessive motion.
IRS-(L or R) DRIFT
U11.0 and later
REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE. Cause - An FMC has detected that the IRS-(L or R) position or velocity data is unreasonable, and deselected IRS-(L or R) due to velocity divergence or position blunder checks.
IRS POS/ORIGIN DISAGREE
U10.7 and later
REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE. Cause - Position information is contradictory.
LNAV BANK ANGLE LIMITED
U10.6 and later
REVIEW THE LNAV COURSE CHANGE. IF COURSE CHANGE EXCEEDS AIRWAY/ROUTE BOUNDARY, CONSIDER FLIGHT PLAN CHANGE. Cause - LNAV is engaged and the airplane is not on a lateral offset and is not near or in an orbit or hold and the airplane is within 5 minutes or less from an LNAV guided course change, and will exceed the airway/route boundaries for
non-flyover turns less than or equal to 135 degrees due to performance limited bank angle. This message does not apply to fixed radius turns.
MAX ALT FLXXX
flight level value
CLEAR THE MESSAGE. Cause - Altitude intervention (as installed) attempt to raise cruise altitude when MCP altitude is above maximum altitude.
MISSED CAPTURE
U14 Removes [MISSED CAPTURE]
CLEAR THE MESSAGE Cause - Proper localizer capture maneuver was performed, but the AFDS did not capture.
MODEL/ENG DATA INVALID
CONTACT MAINTENANCE PERSONNEL. Cause - A valid performance database is not available.
NAV DATA OUT OF DATE
CHECK THE IDENT PAGE AND REVERSE THE DATES FOR ACTIVE NAV DATA IF
REQUIRED. Cause - Effectivity dates of nav database do not agree with date input from clock.
NAV INVALID–TUNE
XXXXX (navaid identifier)
CROSS–CHECK RADIOS AND MANUALLY TUNE THE DESIRED NAVAID. Cause - FMC is unable to auto–tune or receive the navaid for a RNAV or VOR approach procedure.
NO VNAV AFTER XXXXX,
U11.0 and later
AFTER SEQUENCING WAYPOINT XXXXX, VNAV INVALID -
PERF LOGIC APPLIES:
PILOT SHOULD REENTER THE CI USING EITHER THE PREVIOUS CI DISPLAYED OR ENTER A NEW CI. REENGAGE VNAV WHEN CHANGE HAS BEEN EXECUTED. Cause - The descent path is monitored independent of path construction for the following scenarios:
A) - an “at”, “at or above”, “at or below” or “window” constraint is violated
B) - a navigation data base gradient (vertical angle) is violated
If a violation is detected and not resolved, VNAV will disconnect after the point of the violation.
The alerting message is displayed one minute prior to the violation.
OAT DISAGREE - DELETED
U12.0 and later
ENTER UPDATED/CORRECTED OAT ON THE N1 LIMITS PAGE. Cause - A check of entered OAT versus sensed OAT occurs after first engine start. A difference of +/- 6 degrees Celsius between the OAT value on the N1 LIMIT / TAKEOFF REF page
and the engine temperature sensors.
OVERSPEED DISCONNECT
U10.2 and later
MANUALLY REDUCE SPEED AND REENGAGE VNAV. Cause - During path descent and above or below the speed restriction altitude, VNAV disengages when airspeed exceeds FMC speed restriction by more than 15 knots.
PARTIAL ROUTE X LOADED
U11.0 and later
CLEAR THE MESSAGE. Cause - A route is loaded into the active/inactive RTE 1 or 2 flight plan buffer which references data not contained in any of the databases.
PERF DEFAULTS INVALID
CONTACT MAINTENANCE PERSONNEL. Cause - Validity check of performance defaults database has failed.
RESET MCP ALT
U10.5A and later
SELECT LOWER MCP ALTITUDE VALUES AS CLEARANCES PERMIT. Cause - During the FMC cruise phase with VNAV engaged, when within 5 NM of the top-of-descent point without selecting a lower altitude on the AFDS MCP.
RTA UNACHIEVABLE
ENTER AN ACHIEVABLE RTA OR DISCONTINUE THE RTA MODE OF NAVIGATION.
ADJUST PARAMETERS TO MEET THE RTA. Cause - The RTA is not in the computed RTA window under current parameters.
RW/APP TUNE DISAGREE
U10.4 and later
CLEAR THE MESSAGE AND SELECT CORRECT APPROACH FREQUENCY. Cause - During approach, manual tuned approach frequency or channel does not match active flight plan.
RW/APP CRS ERROR
U10.4 and later
CLEAR THE MESSAGE AND SELECT CORRECT MCP COURSE. Cause - During approach, MCP selected course does not match front course for the approach in the active flight plan.
SCANNING DME FAIL
CLEAR THE MESSAGE AND CHECK POSITION. RADIO UPDATING OF FMC POSITION IS NOT AVAILABLE. Cause - Inputs from both frequency scanning DME radios have failed.
SELECT MODE AFTER RTA
SELECT ALTERNATE PERFORMANCE MODE. (ECON, MANUAL SPEED, ETC.) Cause - RTA mode has been discontinued due to sequencing of RTA waypoint or RTA waypoint has been removed from the flight plan.
SINGLE FMC OPERATION
IF THE FMC SOURCE SELECTOR SWITCH IS IN THE “NORMAL” POSITION, MOVE TO “BOTH ON L”. NO ACTION IS REQUIRED IF THE FMC SOURCE SELECTOR SWITCH IS ALREADY POSITIONED TO “BOTH ON L” OR “BOTH ON R”. Cause - The primary FMC has determined that the secondary FMC is not available. (Dual FMC as installed)
SW OPTIONS INVALID
U10.5 and later
RELOAD THE FMC OPC SOFTWARE BY MAINTENANCE. Cause - The CRC performed during power up BIT on the current software options data base has failed, or the CRC of the software options data base that has been loaded via the data loader has failed.
TAKEOFF SPEEDS DELETED
(U12.0 and later) and CDS BP 15
RESELECT NEW V SPEEDS AND CLEAR MESSAGE.
ENTER UPDATED/CORRECTED OAT ON THE N1 LIMITS PAGE, THEN RESELECT NEW V SPEEDS AND CLEAR MESSAGE. Cause - A change to runway, runway data, takeoff thrust selection or performance data is made after the V speeds have been selected, or entered V speeds fail to meet relative value check.
A check, after first engine start, of entered OAT versus sensed OAT has a difference of +/- 6 degrees Celsius.
THRUST REQUIRED
U10.5 and later
CLEAR THE MESSAGE. INCREASE AIRSPEED TO WITHIN 15 KNOTS OF SPEED TARGET. Cause - Airplane is in an underspeed condition.
UNABLE HOLD AIRSPACE
U10.2 and later
REVIEW THE HOLDING PATTERN. IF HOLDING PATTERN EXCEEDS ALLOWABLE HOLDING AIRSPACE, CONSIDER FLIGHT PLAN CHANGE. Cause - The lateral predicted hold path using the bank angle limit causes protected airspace to be exceeded.
