Home' RTCA Documents for Review : C2 Link Systems MASPS_Draft Contents Appendix D
© 2018 RTCA, Inc.
system for that system to manage the maneuver. This would consist of inputting the vector
in the direction of BUBBS plus a holding pattern between BUBBS and GROVE with the
leg lengths such that they would prevent the UA from flying beyond GROVE. If the
controller did not issue the instruction until the UA was almost to the BUBBS waypoint,
the remote pilot might not have sufficient time to program the navigation system. If the
remote pilot determines that there was insufficient time to complete such re-programing,
he/she could manually maneuver (Aviate) the UA by commanding a turn toward GROVE.
This would allow more time to enter the navigation holding pattern information into the
navigation system in the CS, have the new route be uplinked to the UA, have confirmation
of the new route being received, and have the new route activated.
Consequently, short C2 Link System interruptions have minimal impact on the remote
pilot’s ability to perform the Navigate activity. A slight increase in workload to resend the
navigation commands would be the only adverse impact. Additionally, short C2 Link
System interruptions that cause a loss of navigation position updates will not adversely
impact the safety of the aircraft because the UA would be following (for a short time) a
previously approved route of flight.
Long C2 Link System Interruptions
For the purposes of this section, long C2 Link System interruptions are defined as
interruptions that exceed the TET for the C2 Link System. Long interruption limitations
for the remote pilot’s Navigate activities also have an efficiency impact just as for the short
C2 Link System interruptions. Longer C2 Link System interruptions could also mean the
controller would be forced to re-route other aircraft around the UA if he/she did not observe
the UA changing course as directed. In addition, long C2 Link System interruptions could
also lead to the declaration of a Lost C2 Link state. Consequently, this MASPS assumes
that the Navigate TET is the same as the Aviate TET since the impact on the operational
safety and efficiency will be the same.
There are many design choices available to UAS manufacturers that could impact the time
required to execute navigation changes during a flight. The design of the navigation system
is beyond the scope of this MASPS, so it is impossible to determine exact timelines for the
pilot actions regarding navigation input, check, transmit, and confirmation responses from
Availability and Continuity for Long C2 Link System Interruptions
Navigation position information arriving at the CS from the UA over the C2 Link System
is used by the remote pilot to help them Aviate the aircraft and to maintain awareness of
the UA location relative to its planned route of flight and obstacles in the area.
Interruptions in the availability of this navigation position information could result in
degraded DAA remain well clear (Integrate activity) performance. The use of navigation
position information to remain DAA well clear will be addressed in the Integrate remote
pilot activity performance requirements.
Maneuvering the UA relative to terrain and weather will depend on accurate and timely
updates of aircraft navigation position.
If the UA is maneuvering off the programmed route, the number of acceptable missed
navigation position updates would depend on the speed of the aircraft and the dynamic
nature of any maneuver. The impact of the subsequent deviation from the intended route
of flight would also depend on the airspace, obstacles near the UA at the time of the
interruption. However, this situation still has the same safety and efficiency impact as an
interruption of Aviate related information since lost position update can be quickly
Links Archive DO-XYZ_ED-ABC_FRAC_SC236_MASPS Navigation Previous Page Next Page