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.
UNABLE NEXT ALTITUDE
U10.4 and later
CLEAR THE MESSAGE AND REVIEW THE PREDICTION. FOR UNDERSHOOT CONDITION DURING CLIMB, CONSIDER SELECTION OF MAX RATE CLB OR MAX ANGLE
CLB, OR A DIFFERENT N1 LIMIT AS APPROPRIATE. Cause - Unable to meet the next flight plan altitude constraint in a VNAV climb or descent. The message appears only with VNAV engaged.
UNABLE PROC AIRSPACE
U10.6 and later
MODIFY FLIGHT PLAN AS REQUIRED.
CLEAR THE MESSAGE. Cause - Minimum procedure turn built by guidance exceeds the allowable excursion distance.
UNABLE YYY KTS AT XXXXX
U10.7 and later
MODIFY FLIGHT PLAN AS REQUIRED.
CLEAR THE MESSAGE. Cause - Next waypoint speed restriction (speed YYY, at waypoint XXXXX) cannot be met.
UNABLE REQD NAV PERF–RNP
U10.3 and later
REFER TO UNABLE REQD NAV PERF-RNP
NON-NORMAL CHECKLIST IN THE QRH.
NOTE: WHEN ON A PROCEDURE OR AIRWAY WITHOUT AN RNP ALERTING REQUIREMENT, THE FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE IN SP11 CAN BE USED TO VERIFY POSITION.
YW140, YW141,
YW152 - YW164
(SB CHANGES YA573 - YW139, YW142 - YW151)
IF A UNABLE REQD
NAV PERF-RNP IS
SHOWN DURING THE RNP-AR APPROACH, WHETHER THE LATERAL OR VERTICAL RNP ARE
EXCEEDED OR NOT, DO THE GO-AROUND AND MISSED APPROACH PROCEDURE UNLESS SUITABLE VISUAL REFERENCE IS ESTABLISHED AND MAINTAINED. Cause - FMC actual navigation performance is not sufficient for the displayed RNP.
YW140, YW141,
YW152 - YW164
(SB Changes YA573 - YW139, YW142 - YW151)
UNABLE REQD NAV
PERF-RNP
message will be displayed if there is a divergence between IRU-L and IRU-R
inertial altitude, or between IRS-L and IRS-R inertial vertical
speed, when the aircraft is on an RNP-AR approach leg.
VERIFY GW AND FUEL
ENTER FUEL WEIGHT ON PERF INIT PAGE 1/2. PERIODIC UPDATE OF FUEL WEIGHT IS REQUIRED TO KEEP GROSS WEIGHT VALUE CURRENT. Cause - Fuel data becomes invalid, PERF INIT fuel value is replaced with dashes. FMC uses last valid fuel quantity for performance predictions until manual entry is made.
Shows if 30 minutes have elapsed since last manual entry.
Does not show in descent with Vref selected.
VERIFY POS: FMC-FMC
U10.7 and later
REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE. Cause - Position information is contradictory.
VERIFY POS: FMC-GPS
U10.7 and later
REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE. Cause - Position information is contradictory.
VERIFY POS: FMC-RADIO
U10.7 and later
REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE. Cause - Position information is contradictory.
VERIFY POS: IRS-FMC
U10.7 and later
REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE. Cause - Position information is contradictory.
VERIFY POS: IRS-IRS
U10.7 and later
REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE. Cause - Position information is contradictory.
VERIFY POS: IRS-RADIO
U10.7 and later
REFER TO FMC NAVIGATION CHECK SUPPLEMENTARY PROCEDURE. Cause - Position information is contradictory.
VERIFY POSITION
on ground
CLEAR MESSAGE. CHECK ACCURACY OF MANUALLY ENTERED DATA. CROSSCHECK IRS, GPS AND FMC
POSITIONS. MANUALLY RE-ALIGN BOTH IRS’S IF NEEDED. Cause - Position information is contradictory.
VERIFY RNP
U10.3 and later
ENTER APPROPRIATE RNP. Cause - Underlying RNP value is less than manually entered value.
VERIFY TAKEOFF SPEEDS
ON TAKEOFF REF PAGE 1, ACCEPT PREVIOUS V SPEEDS, OR REJECT PREVIOUS V SPEEDS AND ENTER NEW V SPEEDS. Cause - A PERF INIT change has been made after takeoff speeds were specified.
VERIFY TAKEOFF THRUST
U10.7 and later
CLEAR THE MESSAGE. MANUALLY CHANGE TAKEOFF THRUST SETTING, OR ACCEPT UPLINK OF DIFFERENT THRUST SETTING. Cause - With the Takeoff Thrust Auto Selection option enabled, the system determines that the selected takeoff thrust setting is not compatible with the engine thrust rating configuration.
VERIFY VERT RNP
U10.5 and later
CLEAR CDU MESSAGE. ENTER APPROPRIATE VERTICAL RNP. Cause - During an active descent with CDS navigation performance scales enabled, a manually entered vertical RNP is greater than the default vertical RNP.
VNAV DISCONNECT
U10.4 and later
MANUALLY CONTROL THE VERTICAL PATH. Cause - The criteria for VNAV engagement is not satisfied (VNAV disengages).
On approach, with VNAV engaged, the FCC has switched to LVL CHG.
VNAV INVALID-PERF
U10.8 and later
PILOT SHOULD REENTER THE CI USING EITHER THE PREVIOUS CI DISPLAYED OR ENTER A NEW CI. REENGAGE VNAV WHEN CHANGE HAS BEEN EXECUTED. Cause - If the exception affects both the MOD and the ACT flight plan, the Cost Index (CI) will be replaced with box prompts on the PERF INIT page and the message will result.
LNAV is still valid and can navigate the airplane laterally but VNAV will disconnect. Reference section 11.32 for further Software Exception Logic.
ALT CONSTRAINT
XXXXX (waypoint identifier)
CLEAR THE MESSAGE AND REVISE THE ENTRY. Cause - A flight plan modification has caused an altitude conflict with a waypoint that has an altitude constraint.
DATA BASE FULL
GO TO THE NAV DATA PAGES AND DELETE UNNEEDED WAYPOINTS, NAVAIDS, OR AIRPORTS FROM THE APPROPRIATE DATABASE AND RE–ATTEMPT ENTRY. Cause - Entry attempted into a supplemental or temporary navigation database category which is full.
DUPLICATE FLIGHT PLAN ID
U10.3 and later
CLEAR THE MESSAGE AND SELECT A UNIQUE FLIGHT PLAN NAME. Cause - The entry attempted is a duplicate of an existing supplemental flight plan name.
INVALID DELETE
CLEAR THE MESSAGE AND SELECT THE PROPER LINE AFTER THE DEL KEY IS PRESSED. Cause - DEL key operation was attempted for a data line to which it was not applicable.
INVALID ENTRY
CLEAR THE MESSAGE AND SCRATCHPAD ENTRY, AND REPEAT THE ENTRY WITH THE CORRECT DATA. Cause - Attempted data entry has incorrect format, range, etc. for the selected data line. Entered RTA waypoint is not in the flight plan.
INVALID QUAD
U10.2 and later
CLEAR THE MESSAGE AND REVISE THE QUAD ENTRY. Cause - Attempted HOLD page QUAD entry has incorrect format or range.
NO OFFSET AT LEG
XXXXX (waypoint)
CLEAR THE MESSAGE AND AMEND THE ROUTE. Cause - Attempted entry of a lateral offset start or end waypoint XXXXXX that is not offsetable (lateral offset as installed).
NOT IN DATA BASE
CLEAR THE MESSAGE AND CHECK DATA ENTRY, OR ENTER THE REQUIRED INFORMATION INTO THE SUPPLEMENTAL OR TEMPORARY NAVIGATION DATABASE VIA THE NAV DATA PAGES. Cause - FMC does not contain the required data for the entered identifier.
NOT IN FLIGHT PLAN
CLEAR THE MESSAGE AND AMEND THE ENTRY. Cause - RTA waypoint or lateral offset (as installed) start/end waypoint entry is not in the active flight plan.
ROUTE FULL
CLEAR THE MESSAGE AND REVIEW EXISTING AND DESIRED WAYPOINTS AND HOLDING PATTERNS FOR POSSIBLE DELETION. Cause - Entry of more than maximum allowed number of waypoints or holding patterns attempted.
SUPP RTE DATA BASE FULL
U10.3 and later
CLEAR THE MESSAGE, DELETE UNNEEDED SUPPLEMENTAL FLIGHT PLANS AND RE–ATTEMPT ENTRY. Cause - Attempted save of the 11th supplemental flight plan.
ABOVE MAX CERT ALT
DESCEND TO AN ALTITUDE BELOW THE MAXIMUM CERTIFIED ALTITUDE. Cause - The airplane is above its maximum certified altitude.
APPRCH VREF NOT SELECTED
SELECT VREF ON APPROACH REF PAGE. Cause - Airplane has transitioned into approach environment and Vref has not been selected on APPROACH REF page.
ARR N/A FOR RUNWAY
GO TO THE ARRIVALS PAGE AND MODIFY SELECTION. Cause - Runway or approach does not match the selected arrival procedure.
BUFFET ALERT
Only appears if flaps are retracted
BRING THE AIRPLANE BACK WITHIN THE OPERATING ENVELOPE. Cause - Current conditions result in a maneuver margin less than specified.
CHECK FMC FUEL QUANTITY
CHECK THE FUEL QUANTITY INDICATIONS FOR CORRECTNESS. Cause - The FMC has detected an unexpected drop in the fuel quantity.
DRAG REQUIRED
USE SPEEDBRAKES, TRIM OR REDUCED THRUST, AS REQUIRED, TO BRING THE AIRPLANE WITHIN 5 KTS OF FMC TARGET SPEED. Cause - Airspeed is 10 kts or more above FMC target speed or within 5 kts of Vmo/Mmo.
ENTER EO CRZ SPD AND ALT
U10.8 and later
ENTER CRUISE SPEED AND ALTITUDE ON CRUISE PAGE. Cause - Engine-out operation has been terminated and no cruise speed or altitude has been entered.
FMC APP MODE UNAVAIL–GP
U10.5 and later
SELECT AN ALTERNATE APPROACH. CLEAR THE MESSAGE. Cause - The approach selected in the FMC does not have a specified glide path angle for final approach. The FMC approach mode cannot be used for this approach.
FMC APP MODE UNAVAIL–QFE
U10.5 and later
SELECT QNH AS THE LANDING ALTIMETER REFERENCE ON THE APPROACH REF PAGE.
CLEAR THE MESSAGE. Cause - An approach that utilizes FMC generated glide path is in the flight plan, but QFE is selected on the FMC.
INVALID INACTIVE PLAN
U10.8 and later
REENTER A NEW VERSION OF THE INACTIVE PLAN. Cause - An exception has occurred in the INACTIVE plan prior to execution and it has been deleted as a result.
INVALID MOD PLAN
U10.8 and later
REENTER A NEW VERSION OF THE MOD PLAN. Cause - An exception has occurred in the MOD plan and it has been deleted as a result.
INVALID OFFSET
CLEAR THE MESSAGE AND AMEND THE ENTRY. Cause - Desired offset does not meet FMC offset criteria.
KEY/FUNCTION INOP
CLEAR THE MESSAGE OR SELECT ANOTHER CDU PAGE FOR DISPLAY. Cause - A mode key is pressed for which an FMC function has not been implemented or has not been enabled. (FANS MCDU only)
LOC CAP ACTIVE
U14 Removes [LOC CAP ACTIVE]
CLEAR THE MESSAGE MANUALLY, OR WAIT FOR THE AFDS TO SIGNAL RESET STATUS TO THE FMC. Cause - The airplane is approaching its turn onto the localizer or GLS course and will maintain an intercept heading.
LOC CAP CANCELLED
U14 Removes [LOC CAP CANCELLED]
CLEAR THE MESSAGE MANUALLY, OR WAIT FOR THE AFDS TO RESET TO LOC CAP ACTIVE Cause - Flight plan modifications or the airplane condition did not facilitate localizer capture.
MAX ALT FLXXX
flight level value
CLEAR THE MESSAGE OR AMEND THE DATA ENTRY. Cause - Altitude entry on any page is above the maximum altitude for current selected performance margins.
MAX MACH
.XXX/MIN MACH
.XXX OR
MAX CAS .XXX/MIN CAS .XXX
CHANGE THE TARGET SPEED TO WITHIN THE MESSAGE LIMITS OR ENTER A LOWER ALTITUDE. Cause - FMC target speed is greater than the maximum or less than the minimum buffet speed for the entered cruise or step climb altitude.
NO DES PATH AFTER
XXXXX (waypoint)
MODIFY SPEED OR ALTITUDE RESTRICTIONS ON THE RTE LEGS PAGES. Cause - FMC is unable to construct a PATH DES that satisfies all altitude restrictions after XXXXX.
NOT ON INTERCEPT HEADING
MANUALLY PLACE THE AIRPLANE ON AN INTERCEPT HEADING AND REENGAGE LNAV. Cause - Airplane is not within the LNAV capture criteria for the active leg (LNAV disengages).
If the LNAV button is pressed and the airplane is not within the capture criteria. (LNAV will not engage)
OFFSET DELETED
CLEAR THE MESSAGE AND AMEND THE ROUTE. Cause - The entered start waypoint has been deleted from the flight plan. (lateral offset as installed)
OFST ENDS ABEAM XXXXXX
CLEAR THE MESSAGE AND AMEND THE ROUTE. Cause - An invalid offset leg exists between the end waypoint (XXXXXX) and the start of offset or no end waypoint exists.
PERF DEFAULTS DELETED
CONTACT MAINTENANCE PERSONNEL. Cause - Performance database has been automatically deleted due to conflict with performance database limits.
POS SHIFT OVER 50NM
U10.6 and later
CLEAR THE MESSAGE. Cause - A viable position shift is currently selected that will result in an FMC position shift in excess of 50nm when executed.
PROGRAM PIN ERROR
SYSTEM UNUSABLE; ADVISE MAINTENANCE PERSONNEL. THE CLR KEY WILL NOT CLEAR THE MESSAGE. Cause - FMC connector wiring is incorrect.
PROGRAM PIN NOT IN DB
ADVISE MAINTENANCE PERSONNEL Cause - FMC connector wiring or performance database is incorrect.
RESET MCP ALT
SELECT A MCP ALTITUDE VALUE IN THE PROPER DIRECTION (HIGHER FOR CLIMB, LOWER FOR DESCENT). Cause - Normal FMC operation would require flying away from MCP altitude.
RESET MCP APP MODE
U10.5 and later
CLEAR AND REARM FCC APPROACH MODE. CLEAR THE MESSAGE. Cause - A change in the expected approach is made with an FCC approach mode armed or engaged.
RUNWAY N/A FOR SID
CLEAR THE MESSAGE AND CHECK SELECTIONS ON THE DEPARTURES PAGE.
MODIFY AS REQUIRED. Cause - The selected runway is not applicable to the selected departure procedure.
SELECT ACTIVE WPT/LEG
EXECUTE A DIRECT–TO OR LEG INTERCEPT TO TELL THE FMC WHICH LEG OF THE ROUTE IS ACTIVE. Cause - Power–up restart or insertion of a different flight plan while airborne.
STEEP DESCENT AFTER XXXXXX
CHECK ROUTING. Cause - An excessive vertical discontinuity exists after point XXXXXX.
TAI ON ABOVE 10°C
CLEAR THE MESSAGE AND CHECK THE USE OF ANTI–ICING FOR ENGINES AND/OR WINGS. Cause - Airplane is operating with anti–icing with TAT above +10°C.
UNABLE CRZ ALT
CLEAR THE MESSAGE AND REVIEW THE CRZ ALT SELECTION. Cause - FMC predicts that no cruise time is possible at the entered CRZ ALT.
UNABLE MACH. XXX
SELECT A SMALLER MACH NUMBER OR WAIT UNTIL GROSS WEIGHT IS REDUCED SUFFICIENTLY. Cause - The entered cruise Mach is unattainable based on present gross weight.
UNABLE TO OFFSET
CLEAR THE MESSAGE AND AMEND THE ROUTE. Cause - A valid offset cannot be constructed due to geometric limitations.
V SPEEDS UNAVAILABLE
CORRECT INPUTS THAT AFFECT V SPEED COMPUTATION. Cause - FMC cannot compute V speeds (as installed) due to unreasonable
inputs on the RTE, PERF INIT, or TAKEOFF REF
pages.
VERIFY RNP VALUE
CHANGE OR DELETE THE MANUALLY ENTERED RNP. Cause - When entering an RNP the underlying RNP value is smaller than the manually entered value or the ANP is greater than the manually entered RNP.
VERIFY VERT RNP VALUE
U10.5 and later
CLEAR THE MESSAGE. CHANGE OR DELETE THE MANUALLY ENTERED RNP. Cause - With CDS navigation performance scales enabled, a manually entered vertical RNP is greater than the default vertical RNP or manually entered vertical RNP is less that vertical ANP.
XXXX (airport identifier)
ENTER THE AIRPORT IDENTIFIER ON THE ORIGIN DATA LINE. Cause - A REF AIRPORT is
entered on the POS INIT page and no entry of ORIGIN yet appears on RTE page 1.
XXXXX (MCP altitude value)
ENTER THE MCP ALTITUDE VALUE ON THE APPROPRIATE TARGET ALTITUDE DATA LINE. Cause - With the CRZ page displayed, resetting the AFDS MCP altitude to a value different from the CRZ ALT causes the value to appear in the scratchpad.
