SECTION XI DATA LOADER UNIT (DLU)
GROSS WT DISCREPANCY
FMS has detected a significant difference between the gross weight received from the IFDS EFIS and the gross weight computed by the FMS.
One of the weight fields on the FUEL 2/2 page has to be updated in order to clear the message.
HEADING INPUT LOST Total loss of heading input. When not in GPS navigation, the FMS builds up an error during rapid turns, and should be used with caution. No wind computation is available.
Refer to Operator’s Manual Section 15 for operation with a failed heading input.
HIGH ARC EXIT SPEED The combination of current TAS and computed wind may cause the aircraft to overshoot the next flight plan leg.
Reduce speed prior to exiting the arc.
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HIGH GLIDEPATH ANGLE Computed glide-path angle for the selected runway exceeds 3.77 degrees.
No vertical guidance is provided for this approach.
HIGH HOLDING SPEED The combination of current TAS and computed wind may cause the ICAO holding pattern protected airspace to be exceeded. This message is displayed one (1) minute prior to reaching the holding fix and on passage over the fix.
Reduce speed prior to reaching the holding fix.
INDEPENDENT OP In a dual/triple-FMS installation, the identified FMS is now operating independently of the off-side FMS(s), because of at least one of the following reasons:
1. Independent mode manually requested on SETUP 1/1 page. 2. An inter-FMS communication
failure has occurred. 3. The Operational Software
programs are not the same in all FMSs.
4. The active navigation database is not the same in all FMSs. 5. The FMSs have been in a different phase of flight for more than thirty seconds.
Any automatically synchronized item listed in Section 3-5 of the Opertor’s Manual, dual-FMS Operations, must be now performed
independently on each FMS. 1. Clear message.
2. See MESSAGE RECALL and/or MAINT MESSAGE page(s) for more details. Advise maintenance.
3. Verify Op Program on IDENT 1/1 page and advise maintenance if different.
4. Verify active navigation database on IDENT 1/1 page, select appropriate database if possible, otherwise advise maintenance. Verify consistency of altitude input of each FMS.
INS NAV LOST INS function in EGI has failed on the onside and offside FMSs.
INS cannot be used for navigation. Advise maintenance .
INS/DVS NAV LOST No INS/DVS navigation solution is available due to an INS and a DVS failure (SIGMA50H EGI only).
INS/DVS solution cannot be used for navigation.
Advise maintenance .
INS/GPS NAV LOST Communication failure with the EGI on the onside and offside FMSs.
INS/GPS cannot be used for navigation. Advise maintenance .
INS-GPS POS DIFF Excessive drift of the INS position with respect to the GPS position.
Verify aircraft position with a different sensor. Deselect this sensor if necessary.
Advise maintenance.
INS/GPS POS UNCERTAIN The FMS is using embedded INS/GPS (EGI) sensor position data for which the sensor integrity does not meet requirements for the phase of flight and there are no other IFR approved navigation sensors available to cross check the EGI position. This message does not imply that the EGI position is in error, only that confidence in the position accuracy is reduced. This message is enabled only when an EGI other than the Litton LN-100GT is configured and POF (Phase of Flight) error limits are selected in the configuration.
Verify INS/GPS position and monitor HIL (Horizontal Integrity Limit).
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Page May 10, 2007307 IRSx ALIGN FAIL INS/IRS reports alignment failure.Message enabled for LTN-92 and ADIRS interfaces.
LTN-92: Ensure that entered position meets LTN-92 latitude check and 3+3T check. Retry INS initialization on POS INIT page.
ADIRS: Ensure that entered position meets Reasonableness Test and System
Performance Test. Retry IRS initialization on POS INIT page.
IRSx CHECK ACCURACY INS reports that some of its navigation parameters may have become unreliable.
or
FMS determined that INS inertial position drift exceeds 3+3T nm, where T is the INS Time in Nav in hours.
Message enabled for ADIRS interfaces.
Move appropriate INS/IRS Mode Selector Unit to ATTitude position.
If attitude data of INS/IRS seems unreliable, switch this INS/IRS to OFF.
IRSx CYCLE OFF/NAV ADIRS alignment fault. Cycle Mode Selector Unit through OFF and back to either NAV or ALIGN.
IRSx ENTER HEADING In Attitude mode, magnetic heading must be manually updated. Message enabled for ADIRS interface.
Magnetic heading must be manually entered in SET IRS HDG field of POS INIT 1/2 page every 15 minutes.
IRSx ENTER PPOS INS requests position initialization. Message enabled for LTN-92 and ADIRS interfaces.
Perform INS/IRS initialization on POS INIT page. Enter position on POS INIT page.
IRSx ON BAT INS/IRS reports that AC power is too low and is operating on DC backup power. If the backup power source is a battery unit, 15 to 30 minutes of operation are available with a fully charged battery. If primary power is not restored promptly, the battery voltage will fall below the level required to operate the INS/IRS. Message enabled for LTN-92 and ADIRS interfaces
Verify IRS AC power.
IRSx SELECT ATTITUDE LTN-92 INS reports invalid navigation data. INS outputs still valid: pitch, roll and platform heading. INS cannot be used in FMS-based inertial navigation mode.
FMS-based inertial navigation mode, heading and altitude inputs still available as long as one inertial sensor is still operating normally.
Move appropriate INS Mode Selector Unit switch position to ATT position.
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KALMAN NAV LOST Kalman filter navigator is not available as a backup navigation source. or
The APIRS measurements for the Kalman filter are not ready. or The APIRS measurements for the Kalman filter are out of range.
Avoid conducting low level altitude mission where GPS signal may be affected.
LOW BATTERY POWER The power level of the internal battery is low. Manually-entered data may be lost if there is a primary power interruption during flight.
After any power interruption, monitor system performance and re-enter data as required. Advise maintenance.
MANUAL WPT