5 - PROCEDURES112 190-00356-00 Rev GFlying the LP ApproachFlying the LP ApproachLP approach capability is available for units with SWVersion 3.30, or later.An LP approach is flown the same as an LPVapproach, except that vertical guidance is not provided.Angular scaling is similar to a localizer approach. MostLP approaches have step down altitudes associated withthem.1. Within 30 nautical miles of the destination, the400W-series unit switches from en route modeto terminal mode and the CDI scale transitionsfrom 2.0 to 1.0 nautical miles, full scale deflec-tion.2. As you approach the IAF, a turn direction mes-sage appears on the bottom of the screen.3. As the distance (DIST) to the IAF approacheszero, the message is replaced by a time to turnadvisory that counts down 10 seconds prior tothe turn.4. As you approach the FAF, the 400W-seriesunit will begin to automatically rescale in anangular fashion. This will allow the LP approachto be flown in the same fashion as a standardlocalizer approach. At 2.0 nautical miles fromthe FAF, CDI scaling is tightened from up toeither 2° or 0.3 nautical miles, full scale deflec-tion, whichever is smaller.5. Sixty seconds prior to reaching the FAF, the400W-series unit will check the requiredHorizontal Alarm Limit (HAL) to ensure the GPSposition integrity is within limits to completethe LP non-precision approach. In the eventthe HAL limits are exceeded, the approach willbe downgraded, when available, indicated by“LNAV” on the moving map, otherwise theapproach will be aborted. A message will notethat the approach is downgraded and the NAVindicator will be flagged. You may continue theapproach using LNAV non-precision minimumsif there are LNAV minimums for this approach.In the rare event the GPS HAL limits cannotmeet non-precision limits, the 400W-series unitwill notify the pilot with a message to abort theapproach. The 400W-series unit will revert toterminal limits of 1.0 NM to support navigationto the missed approach.6. As you cross the FAF, the destination sequencesto the MAP. With the needle on the external CDI(or HSI) centered, fly toward the MAP, observingthe altitude minimums dictated by the approachplate.7. When viewing the Map Page, you’ll note thatthe final course segment is displayed in ma-genta (the active leg of the flight plan alwaysappears in magenta).8. As you approach the MAP, a waypoint message(“Arriving at Waypoint”) appears on the bottomof the screen.9. At the MAP initiate the missed approach, ifnecessary. Once the 400W-series unit crossesthe MAP sequencing will be suspended. Preparethe aircraft for missed approach operation.Press the OBS key to sequence to the MissedApproach procedure.NOTE: For missed approaches with heading legs,fly manually until the ifrst active course leg isreached, as described in earlier sections.10. Fly the guidance provided by the 400W-seriesunit to the MAHP and hold.
