8a Data Available and TC Type (Vertical) Target Altitude Target Altitude Target Altitude
8b TC Altitude 15,000 ft 15,000 ft 15,000 ft
8c TC Altitude Type MSL MSL MSL
8d (Reserved) * * *
8e (Reserved) * * *
8f (Reserved) * * *
8g Command/Planned -V Command Command Command
* Reserved for Future MASPS Revisions
In Figure 5a, the aircraft is flying in cruise at FL350, approaching the top of descent. The FMS cruise altitude provides the vertical target source. It has a single FMS altitude constraint at End of Descent (cross ABC at 3,000 ft). The MCP altitude is set to an intermediate value of 15,000 ft. Since the aircraft is limited by MCP altitude, it will level off at 15,000 ft, given the current automation state. This path is the command trajectory. If the pilot resets the MCP altitude prior to reaching 15,000 ft, the aircraft will continue toward the End of Descent at ABC. ABC is included as a planned trajectory point. It has a known 3D location and the FMS time estimate may be provided.
Table 6. Trajectory Change Report Elements for Figure 5a
Element # Contents TC+0 Report Values (TCP 1) TC+1 Report Values (TCP 2) TC+2 Report Values (TCP 3)
4 TC Sequence Number 0 1 2
5a TC Cycle Number 0 0 0
5b (Reserved) * * *
6 Time to Go (TTG) TTG-TOD TTG-MCP_ALT TTG-ABC
7a Data Available and TC Type (Horizontal) Course-to-Fix Course-to-Fix Course-to-Fix
7b TC Latitude LatitudeTOD Estimate LatitudeABC
7c TC Longitude LongitudeTOD Estimate LongitudeABC
7d Turn Radius X X X
7e Track to TCP 090 090 090
7f Track from TCP X X X
7g (Reserved) * * *
7h Command/Planned -H Command Command Command
8a Data Available and TC Type (Vertical) Top-of-Descent Target Altitude Target Altitude
8b TC Altitude 350 15,000 ft 3,000 ft
8c TC Altitude Type Flight Level MSL MSL
8d (Reserved) * * *
8e (Reserved) * * *
8f (Reserved) * * *
8g Command/Planned -V Command Command Planned
*Reserved for Future MASPS Revisions 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：Automatic Dependent Surveillance(15)
