5. RNAV
Aircraft Capabilities
RNAV 1 AIRCRAFT CAPABILITY
• Large database SIDs/STARs loaded automatically & able to
interpret coded SIDs/STARs
• Comprehensive pilot display requirements
• Displays a minimum of 10 waypoints
• Track accuracy +/- 1 nm (95% of total flight time)
• 'DIRECT TO' function required
• 'Fly-by' and 'fly-over' capabilities required
• Parallel off-set not required
• Fully suitable for Terminal Control Area
6. RNAV
TMA RNAV SIDs and STARs
• Defined by waypoints
• Limitations of RNAV over 'conventional‘ SIDs/STARs
Not all aircraft are RNAV1 equipped
Aircraft capability has to be identified
• 2 methods used to terminate STARs
'Closed' STARs :
uninterrupted RNAV nominal track to the final approach
segment
'Open' STARs :
RNAV nominal track up to a waypoint abeam the final approach
fix
7. RNAV
Waypoint
Waypoint
A specified geographical location used to define an area
navigation route or the flight path of an aircraft employing area
navigation
Fly-by waypoint
A waypoint which requires turn anticipation to allow tangential
interception of the next segment of a route or procedure
Flyover waypoint
A waypoint at which a turn is initiated in order to join the next
segment of a route or procedure
8. RNAV
Waypoint
Factors affecting turn anticipation and recovery turn
• Speed
• Level
• Amount of turn between segments
• Type of aircraft and System manufacturer
9. RNAV
TMA operation
Terrain clearance
TERRAIN CLEARANCE
• Existing responsibilities are not changed.
• It DOES NOT relieve:
Pilots of their responsibility to ensure that any clearances are safe
in respect to terrain clearance
Air Traffic Control (ATC) of its responsibility to assign levels which
are at or above established minimum flight altitudes
10. RNAV
TMA operation
Level Categories
CATEGORIES OF LEVEL INFORMATION
Minimum Flight Altitude
Cleared levels
Level Restrictions
?
11. RNAV
TMA operation
‘DIRECT TO’ instruction
'DIRECT TO' instruction in the TMA
• All RNAV 1 certified aircraft are able to execute 'DIRECT TO'
waypoints
• ATC could consider 'DIRECT TO' as an alternative to radar vectoring
for RNAV 1 capable aircraft
• By using 'DIRECT TO' instead of radar vectoring, RNAV 1 systems
maintain 'distance to go' information
RNAV 'DIRECT TO' instructions are not radar vectors
12. RNAV
TMA operation
‘DIRECT TO’ instruction
Inability to comply ‘DIRECT TO’ instruction
• navigation computer problem
• too close to waypoint specified
• angle of turn/speed too great
• waypoint not displayed on the Flight Management System (FMS)
for pilot selection
• waypoint not part of SID/STAR
• SID/STAR not assigned
13. RNAV
TMA operation
‘DIRECT TO’ instruction
'DIRECT TO' a waypoint which is part of the SID/STAR
• The pilot selects the waypoint in the FMS
• The FMS and Navigation Display (ND) are updated maintaining
details of the route from the 'DIRECT TO' waypoint onwards
• The aircraft continues with the SID/STAR after reaching the
waypoint
• The aircraft is expected to meet level/speed restrictions if
published, if the cleared level makes this possible
• 'DIRECT TO' could shorten track miles impacting the aircraft's
ability to meet level and speed restrictions
14. RNAV
TMA operation
‘DIRECT TO’ instruction
'DIRECT TO' a waypoint which is not part of the SID/ STAR
• It takes time for the pilot to retrieve the waypoint from the database
• The clearance for the SID/STAR is cancelled and previously loaded
SID/STAR is dropped by the RNAV system
• No further routeing is maintained or displayed
• The aircraft requires explicit routeing after the waypoint from ATC
• RNAV systems will revert to "present heading mode" after reaching the
waypoint
15. RNAV
TMA operation
‘DIRECT TO’ instruction
CONSTRAINTS OF 'DIRECT TO' INSTRUCTIONS IN THE TMA
• ‘Active' waypoints dynamically updated
• As waypoints are passed, they are removed from the 'active'
waypoints list
• The aircraft can have considerable difficulty manoeuvring 'DIRECT
TO' a waypoint which is considered by the RNAV system, to have
been passed
• 'DIRECT TO' should only be used for waypoints ahead of the aircraft
16. RNAV
TMA operation
Radar Vectoring and RNAV SIDs/STARs
RADAR VECTORING & RNAV SIDs/STARs
Aircraft may require considerable manipulation of the RNAV system in
order to resume a SID/STAR cancelled by ATC
Arrivals:
If radar vectoring is initiated, ATC should consider continuing with
radar vectoring until intercept of the final approach aid
Departures:
If radar vectoring is initiated, ATC should consider:
• remaining with radar vectoring until the aircraft is in a position to
join the en-route ATS route structure, or
• issuing a 'DIRECT TO' the last waypoint of the RNAV SID
17. RNAV
TMA operation
Radiotelephony Phraseology for RNAV TMA
• Checking if Aircraft able to accept a SID/STAR
"ADVISE IF ABLE (designator) DEPARTURE [or ARRIVAL]“
• If aircraft unable to accept ATC issued RNAV SID/STAR
“UNABLE (designator) DEPARTURE [or ARRIVAL] DUE RNAV TYPE"
• If aircraft unable to continue on issued RNAV SID/STAR due to
some failure or degradation of their RNAV system
“UNABLE RNAV DUE EQUIPMENT"
• If ATC unable to issue requested RNAV SID/STAR
"UNABLE TO ISSUE (designator) DEPARTURE [or ARRIVAL] DUE RNAV TYPE"
18. TMA operation
RNAV CAPABILITY INDICATION
RNAV CAPABILITY INDICATION
Aircraft equipment capabilities are indicated on the Flight Plan
RNAV 1
Flight Plan (FPL) item 10 will include 'R ‘ and item 18 PBN/ will
include
D1-D4
RNAV 5
FPL item 10 will include 'R ' and item 18 PBN/ will include B1-B5
