With a single operational FMC, during VOR approaches one pilot must have raw data from the VOR associated with the approach displayed on the RDMI or RMI (as installed) with separate DME display, or HSI in a VOR mode no later than the final approach fix. During other non-localizer based approaches where the FMC is used for course or path tracking (VOR, TACAN, NDB, RNAV, GPS, etc.), Boeing recommends monitoring raw data if it is available. For airplanes with two operational FMCs, two IRSs and two GPS receivers (or two DME receivers if GPS updating is not available), or if the FMC is RNP/ANP capable, raw data monitoring is not required.
Note: The FMC is RNP/ANP capable if RNP/ANP is displayed on the applicable FMC POS REF page.
During non-localizer based approaches where the FMC is used for course or path tracking (TACAN, NDB, RNAV etc.), if only one FMC or one IRS or one DME is operational, or the FMC is not RNP capable, raw data must be monitored or checked if available for correct navigation or the update mode should be checked no later than final approach.
During single FMC, single IRU, or single DME or single GPS operation, in the event the single operational FMC, IRU, DME, or GPS fails during the FMC approach, there must be a non-FMC means of navigation available for a missed approach such as VOR/NDB raw data and/or radar, and there must be a non - FMC approach available. Failure of the remaining single DME need not be considered if GPS updating is being used.
MAP Displays and Raw Data
The map mode should be used to the maximum extent practicable. The map display provides a plan view of the approach, including final approach and missed approach routing. The map increases crew awareness of progress and position during the approach.
The map is particularly useful when the inbound course does not align with runway centerline and allows the pilot to clearly determine the type of alignment maneuver required. The map can be used to integrate weather radar returns, terrain or traffic information within the approach path and airport area.
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October 31, 2003 FCT 757 (TM) 5.29
When raw data VOR information is required, the manual tuning feature may be used to pretune the appropriate frequency and select the course prior to starting the approach. The frequency may then be returned to automatic control. When required for the approach, selection of the VOR mode restores the preset frequency. With a single operational FMC, monitoring of VOR raw data is required no later than the final approach fix. Use of the VOR course and DME information displayed on the RDMI or RMI (as installed) with DME display, or one EHSI in a VOR mode satisfies this requirement.
Note: When appropriate, compare airplane position on the map with ILS, VOR,
DME, and ADF systems to detect possible map shift errors. Use of the
VOR mode selectable on the EFIS control panel is the recommended
method for making this comparison. If ADF pointers are available, they
should be displayed on the map.
RNAV Approaches
RNAV approaches may be flown with any RNP alerting capable FMC (Pegasus) provided the RNP being used is equal to or less than the RNP specified for the approach and is consistent with the AFM demonstrated RNP capability.
FMCs that are not RNP alerting capable (prior to Pegasus) may be used for RNAV approaches provided the following requirements are met:
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