*Reserved for Future MASPS Revisions
“Estimate”: Element contents filled with FMS lat/long estimates, if available.
The partially equipped aircraft flying the Figure 8 trajectory (Table 7b) has an MCP and FMS. The FMS cannot predict the location of the path intercept and does not provide lateral position for the MCP level off. Target altitude in this case represents the selected altitude provided by the TS report. Since the FMS does not support path intercepts, no TC report is provided for TCP #1 (a blank column is provided for clarity). The possibility of an intermediate horizontal TCP requires all successive horizontal TCPs to be labeled as “planned”. All vertical TCPs are “planned” because the aircraft cannot fully determine next target altitude. For instance, it has no means to determine if an intermediate level off (such as an altitude constraint) will occur between the aircraft’s current position and the MCP level off at FL210. (Note: TTG to MCP level off can be estimated from estimated altitude at ABC, TTG to ABC, and climb rate, if no FMS avionics bus gives a time estimate to MCP level off.)
Table 7b. Trajectory Change Report Elements for Figure 8 (Partially Equipped Aircraft)
# Contents No Report for Intercept Point TC+0 Report Values (TCP 2) TC+1 Report Values (TCP 3) TC+2 Report Values (TCP 4)
4 TC Sequence Number 0 1 2
5a TC Cycle Number 0 0 0
5b (Reserved) * * *
6 Time to Go (TTG) TTG-ABC TTG -MCP_ALT TTG-DEF
7a Data Available and TC Type (Horiz) TF and Fly-by Not Available TF and Fly-by
7b TC Latitude LatitudeABC X LatitudeDEF
7c TC Longitude LongitudeABC X LongitudeDEF
7d Turn Radius RadiusABC X RadiusDEF
7e Track to TCP 090 X 120
7f Track from TCP 120 X Track from DEF
7g (Reserved) * * *
7h Command/Planned (Horizontal) Planned X Planned
8a Data Available and TC Type (Vertical) Estimate Target Altitude Target Altitude
8b TC Altitude Estimate 210 210
8c TC Altitude Type Flight Level Flight Level Flight Level
8d (Reserved) * * *
8e (Reserved) * * *
8f (Reserved) * * *
8g Command/Planned (Vertical) Planned Planned Planned
*Reserved for Future MASPS Revisions
“Estimate”: Element contents filled with FMS lat/long estimates, if available.
“X”: Information not available.
The TC report format provides a flexible structure for accommodating aircraft with widely varying navigation and automatic flight equipage. In addition to the partially equipped FMS aircraft represented in Figure 7b, numerous other variations are possible. For example, many RNAV and GPS systems only allow lateral waypoints and have no associated altitude estimate. Capability is also provisioned in the TC report for handling additional TC types in future MASPS revisions. As discussed above, future DO-242 revisions may include the capability to report waypoint constraints. Altitude constraints are likely to benefit a number of applications,4-5,7 and space is allocated for these point types in DO-242A. 中國航空網(wǎng) www.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：Automatic Dependent Surveillance(17)
