You are using an unsupported browser. Please update your browser to the latest version on or before July 31, 2020.
close

Top of Descent Functionality

A green circular top of descent (TOD) marker and “TOD” label are drawn on the map when flying “on-path” along the FMS flight plan, giving a clear visual cue when it is appropriate to begin the enroute descent. • TOD is based on the vertical constraint associated with a downpath waypoint. (500fpm by default-editable in user settings) • To generate the TOD feature: - There must be an altitude constraint defined on at least one down-path waypoint at least 50’ below present altitude - There must be a valid GPS MSL Altitude or Baro Altitude - The aircraft is less than 2nm from the active leg centerline - Aircraft course is within 45 degrees of Desired Track (DTK) • TOD function is not available on any waypoint of an approach past the Final Approach Fix (FAF), or in holds, or procedures turns.

In this example we are enroute at 10,000 ft and want to cross GTH at 7,400. We have programmed 7,400 ft into the altitude constraint window of the GTH waypoint on the FMS.

There is an associated “door bell” tone and CAS countdown message 10 seconds prior to reaching the TOD point. • The TOD Marker and CAS message are removed from the map immediately after passing the TOD point. • Notes: - TOD tone requires wiring to the audio panel. - “TOD” label may be auto-decluttered from the map depending on map range and feature density.

In this example we descended from 8,000 ft. at PVW to be at 6,500 ft when we get to TXO. CAS Message (and TOD audio tone) tells us when to start our 500FPM descent.

The FMS uses a default of 500 feet per minute descent rate • Descent Rate can be edited on the AUX→Setup→FMS Setup page • Keep these the same values in dual IFD installations.

A small green arc (aka “Boeing Banana”) will be drawn on the map that depicts the geographic point where, at the current vertical speed, the aircraft will reach the altitude target. • The altitude target is any crossing restriction on a waypoint that is either manually entered or a part of a procedure. • Green arc will be removed from the map when current aircraft altitude is within 150 feet of the target altitude.

In this example we crossed GTH at 7,400 ft and we set the FMS to 8,000ft at PVW. At current VS, the banana shows when we will reach the target altitude of 8,000ft.

  • 699
  • 08-Nov-2022
  • 2502 Views