Transcript Navigation & flight planning

Navigation & flight planning
by FMS-equipped aircraft
10-11-12-13 September 2002-Morocco
ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR
AI/EE-A 441.0144/01
Table of contents
P.3
P.26
CI leg type
P.4 An overview of aircraft avionics
P.27
CR leg type
P.5 GPS PRIMARY navigation
P.28
AF leg type
P.29
VA leg type
P.30
VD leg type
P.31
VI leg type
P.32
VM leg type
P.33
VR leg type
P.34
PI leg type
P.35
HA, HF, HM leg types
Navigation & flight management
P.8 RNP navigation
P.10
P.13
Flight management
P.11
Flight planning
P.12
Vertical navigation
Navigation database : ARINC 424 format
P.14
Path terminator concept
P.15
IF leg type
P.16
TF leg type
P.17
RF leg type (new leg type)
P.18
CF leg type
P.19
DF leg type
P.20
FA leg type
P.21
FC leg type
P.22
FD leg type
P.45
Issues summary
P.23
FM leg type
P.46
Short term
P.24
CA leg type
P.52
Medium term
P.25
CD leg type
P.54
Longer term
P.36
P.37
P.44
ARINC 424 leg transitions
Navigation database related issues
P.38
Compatibility...
P.39
Production process
P.40
Some top level issues
Recommendations
Navigation & flight management
10-11-12-13 September 2002-Morocco
ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR
An overview of aircraft avionics ...

Modern avionics have considerably improved flight
safety on non-precision approaches :
 accurate
 flight
position (RNP 0.3)
plan display on EFIS
 reference
approach path
 automated
lateral guidance
 automated
vertical guidance
 ground
proximity warning system (GPWS)
 terrain
display on EFIS (EGPWS)
 terrain
clearance floor warnings (EGPWS)
An overview of aircraft avionics ...
500’ AGL
5 NM
700’
AGL
12 NM15 NM
GPS PRIMARY navigation

AIRBUS is promoting GPS PRIMARY navigation
 All
new A318/A319/A320/A321/A330/A340 production
aircraft are fitted with GPS PRIMARY capable equipment

Ground navaids are only used as a backup
 VOR,

DME
ADF is not used for navigation
 only
for procedural navigation check
AIRBUS system GPS architecture

Hybrid (A320 family & A340 family)
EGPWS
MMR or
GPSSU
GPS raw data GPS
position
FMS
ADIRS
IRS position
GPIRS position
FMS position
AIRBUS system GPS architecture

Autonomous (A300-600/A310 family, retrofit solution
for A320 family with older ADIRS)
EGPWS
FMS
MMR
GPS position
IRS position
FMS position
IRS
GPS PRIMARY crew interface

In GPS PRIMARY mode, on-board system integrity has
a confidence greater than 99.9%, so the FMS position
can be relied upon without any additional navigation
cross check (using ground based navaids)

Clear status of GPS PRIMARY is therefore provided to
the crew
GPS PRIMARY crew interface
CRZ
FL350
CLB FLT4567890
OPT
REC MAX
FL370
FL390
<REPORT
UPDATE AT
*[
]
BRG /DIST
---° /----.- TO [
]
PREDICTIVE
<GPS
GPS PRIMARY
REQUIRED ACCUR ESTIMATED
2.1NM
HIGH
0.16NM
GPS PRIMARY
GPS PRIMARY
CRZ
FL350
CLB FLT4567890
OPT
REC MAX
FL370
FL390
<REPORT
UPDATE AT
*[
]
BRG /DIST
---° /----.- TO [
]
PREDICTIVE
<GPS
REQUIRED ACCUR ESTIMATED
2.1NM
HIGH
0.28NM
GPS PRIMARY LOST
GPS PRIMARY LOST
+ triple click during approach
RNP navigation

AIRBUS is promoting RNP (required navigation
performance)

All A318/A319/A320/A321/A330/A340 aircraft are
fitted or have been retrofitted with RNP capable
equipment

RNP allows crew awareness of estimated aircraft
position accuracy compared to procedure designer’s
required performance assumptions
RNP crew interface

RNP management provides HIGH and LOW navigation
accuracy system monitoring against the Required
Navigation Performance

The system estimated accuracy has a 95% confidence
NAV ACCUR UPGRAD
RNP crew interface
CRZ
FL350
CLB FLT4567890
OPT
REC MAX
FL370
FL390
<REPORT
UPDATE AT
*[
]
BRG /DIST
---° /----.- TO [
]
PREDICTIVE
<GPS
REQUIRED ACCUR ESTIMATED
0.3NM
HIGH
0.28NM
NAV ACCUR UPGRAD
NAV ACCUR UPGRAD
CRZ
FL350
CLB FLT4567890
OPT
REC MAX
FL370
FL390
<REPORT
UPDATE AT
*[
]
BRG /DIST
---° /----.- TO [
]
PREDICTIVE
<GPS
REQUIRED ACCUR ESTIMATED
0.3NM
LOW
0.56NM
NAV ACCUR DOWNGRAD
NAV ACCUR DOWNGRAD
AIRBUS flight management details

Multi-sensor navigation & automatic navaid tuning

triple IRS, dual VOR & DME, GPS
 nIRS only,
 LOC
nIRS/VOR/DME, nIRS/DME/DME, nIRS/GPS
updating

RNP management

GPS primary navigation
 RAIM
or AIME on-board integrity monitoring
 certified for RNP 0.3

NM use
Datalink

including F-PLN, T/O DATA and WIND uplink capability from
AOC (Airline Operational Control)
AIRBUS flight management details

4D flight planning & predictions

runway to runway 4D pre-computed optimized flight profile

real time optimization

decelerated approach profile, 3D non-precision approaches

full autopilot coupling capability (dual FMS, dual monitored
AP)

time resolution 1 minute, guidance accuracy around 2 minutes
 planned improvement
than 30 s
to 1 second resolution, accuracy better
Flight planning

Origin

Departure SID

Engine out SID

En-route

Arrival STAR

Approach

Destination

Missed approach

Alternate flight plan
Vertical flight management
CRUISE FL
STEP FL
pressurization
segment
IDLE path
SPEED
LIMIT
SPEED
LIMIT
ALTITUDE
CONSTRAINTS
SPEED
CONSTRAINTS
ACCELERATION ALT
THRUST REDUCTION ALT
TAKE-OFF
SPEEDS
ALTITUDE
CONSTRAINTS
geometric path
approach path
SPEED
D
CONSTRAINTS
APPROACH
SPEEDS
TIME
CONSTRAINT
DESTINATION
ORIGIN
TAKEOFF
CLIMB
CRUISE
DESCENT
APPROACH
Navigation database : ARINC 424
10-11-12-13 September 2002-Morocco
ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR
ARINC 424 path terminator concept

The Path and Terminator concept is a means to permit
coding of Terminal Area Procedures, SIDs, STARs and
Approach Procedures

Charted procedure are translated into a sequence of
ARINC 424 legs in the Navigation Database

Flight plans are entered into the FMS by using
procedures from the navigation database and chaining
them together
ARINC 424 path terminator concept

23 leg types have been created to translate into computer
language (FMS), procedure designed for clock &
compass manual flight

It’s high time to implement RNAV, using only DO236
preferred leg types: IF, TF, RF which are fixed and
without possible interpretation

The leg type is specified at the end point : “path
terminator concept”
IF leg type

The Initial Fix or IF Leg defines a database fix as a point
in space

It is only required to define the beginning of a route or
procedure
TF leg type

Track to a Fix or TF Leg defines a great circle track over
ground between two known databases fixes

Preferred method for specification of straight legs
(course or heading can be mentioned on charts, but
designer should ensure TF leg is used for coding)
RF leg type (new leg type)

Constant Radius Arc or RF Leg defines a constant radius
turn between two database fixes, lines tangent to the arc
and a center fix
CF leg type

Course to a Fix or CF Leg defines a specified course to a
specific database fix

TF legs should be used instead of CF whenever possible
to avoid magnetic variation issues
DF leg type

Direct to a Fix or DF Leg defines an unspecified track
starting from an undefined position to a specified fix

Procedure designers should take into account the FMS
flight path depends on initial aircraft heading as well
FA leg type

Fix to an Altitude or FA Leg defines a specified track
over ground from a database fix to a specified altitude at
an unspecified position
FC leg type

Track from a Fix from a Distance or FC Leg defines a
specified track over ground from a database fix for a
specific distance
FD leg type

Track from a Fix to a DME Distance or FD Leg defines a
specified track over ground from a database fix to a
specific DME Distance which is from a specific database
DME Navaid
FM leg type

From a Fix to a Manual termination or FM Leg defines a
specified track over ground from a database fix until
Manual termination of the leg
CA leg type

Course to an Altitude or CA Leg defines a specified
course to a specific altitude at an unspecified position
CD leg type

Course to a DME Distance or CD Leg defines a specified
course to a specific DME Distance which is from a
specific database DME Navaid
CI leg type

Course to an Intercept or CI Leg defines a specified
course to intercept a subsequent leg
CR leg type

Course to a Radial termination or CR Leg defines a
course to a specified Radial from a specific database
VOR Navaid
AF leg type

Arc to a Fix or AF Leg defines a track over ground at
specified constant distance from a database DME Navaid
VA leg type

Heading to an Altitude termination or VA Leg defines a
specified heading to a specific Altitude termination at an
unspecified position
VD leg type

Heading to a DME Distance termination or VD Leg
defines a specified heading terminating at a specified
DME Distance from a specific database DME Navaid
VI leg type

Heading to an Intercept or VI Leg defines a specified
heading to intercept the subsequent leg at an unspecified
position
VM leg type

Heading to a Manual termination or VM Leg defines a
specified heading until a Manual termination
VR leg type

Heading to a Radial termination or VR Leg defines a
specified heading to a specified radial from a specific
database VOR Navaid
PI leg type

Procedure Turn or PI Leg defines a course reversal
starting at a specific database fix, includes Outbound Leg
followed by a left or right turn and 180 degree course
reversal to intercept the next leg
HA, HF, HM leg types

Racetrack Course Reversal or HA, HF and HM Leg
Types define racetrack pattern or course reversals at a
specified database fix
HA = Altitude Termination
HF = Single circuit terminating
at the fix (base turn)
HM = Manual Termination
ARINC 424 - allowable leg transitions
* = The IF leg is coded only
when the altitude constraints at
each end of the “FX”, “HX” or
“PI” leg are different.
& = A CF/DF, DF/DF or FC/DF
sequence should only be used
when the termination of the first
leg must be over flown,
otherwise alternative coding
should be used.
# = The IF/RF combination is
only permitted at the start of the
final approach for FMS, GPS or
MLS coding and only when a
straight line, fixed terminated
transition proceeds the start of
the final.
Navigation database related issues
10-11-12-13 September 2002-Morocco
ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR
Compatibility...
Navigation data production process
Procedure design
by Civil Aviation Authorities
Data Supplier
AIP
ARINC 424 “master” file
FMS Database Processing
FMS
Packed Data
operator
responsibility
Some top level issues

Navigation database process is *not* certified

Transcription of procedures in “computer” language
(ARINC 424) requires interpretation
 Procedure
designer intent is currently only published under
“pilot language” format

Each FMS implementation & logic is different
 May

results in different flight paths and SOP
Charts and aircraft navigation displays differ
 Increased
 Training
risk of Human error
costs
Reminder - flight plan construction

Charted procedure are translated into a sequence of
ARINC 424 legs in the Navigation Database

Flight plans are entered into the FMS by calling
procedures from the navigation database

Procedure segments are chained together (or melded) to
form the FMS flight plan
Example : F-PLN procedure melding

Procedures are chained together to form the FMS flight
plan. Example :
Arrival chart
Airways chart
Approach chart
STAR-approach
transition (VIA)
Enroute
(airways)
STAR-enroute
transition
STAR
Approach
Example : procedure compatibility ?

Possible procedure misconnects between en-route,
arrival, and approach charts

Possible discontinuities between or inside procedures

Incompatible or conflicting altitude requirements
between arrival and approach charts
Navigation database recommendations
10-11-12-13 September 2002-Morocco
ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR
Waypoint naming issues
 Different
approach procedure types (ILS/LOC/RNAV…)
use different trajectories and/or waypoint names without
reason
 Unnamed
 Same
waypoints on charts are assigned default names
waypoint names used at different locations
 Chart
wording leading to usage of leg types which cause
the FMS to create its own waypoints, with names which do
not match chart
 Coding
chart
constraints lead to creation of waypoints not on the
Procedure trajectory issues

Chart wording and/or coding rules lead to coding of
magnetic course leg types such as CF legs

Chart wording and/or coding rules lead to bad coding of
vertical descent angles, which are critical to a correct
vertical path

IFR minimum altitudes often coded as “AT” constraints

Overfly waypoints trajectories are not repeatable

Barometric temperature limitations should be indicated
on charts
Why not use overfly waypoints ?

Overfly waypoints : depending on wind, aircraft speed,
bank angle limitation etc… the FMS trajectory will be
different
overfly wpt
trajectory
not repeatable
Why use fly-by waypoints ?

Fly-by waypoints : better trajectory control is achieved
as the FMS will track a pre-computed curve
fly-by wpt
controlled
trajectory
Why not use CF legs ?

CF leg magnetic course angles may mismatch :
excessive roll
maneuvering
N
N
Why use TF legs ?

TF legs always fit, independently of magnetic variation :
Why code FPA constraint on each
FINAL leg ?
FPA matches altitude
constraint
FPA greater than
altitude constraint
IDLE segment
FPA smaller than
altitude constraint
No FPA
Why not use AT altitude constraints ?

Using AT constraints may cause undesired vertical path :
navigation database vertical angle
MDA
navigation database vertical angle
MAP
Why use AT_OR_ABOVE altitude
constraints ?

Using AT_OR_ABOVE constraints and FPA constraint
on each leg ensures seamless path
navigation database vertical angle
MDA
navigation database vertical angle
MAP
Medium term - recommendations

Implementation of DO201A by civil aviation authorities for
procedure publication

Implementation of DO200A by data providers

Implementation of RTCA DO236 / EUROCAE ED-75

Implementation of ATA Chart, Data and Avionics Harmonization
Top Priorities

Improved transatlantic coordination between working groups,
authorities & industry

ARINC 424, ATA FMS/RNAV Task Force, TARA, RTCA SC181 & 193, Eurocae WG-13 & 44, FAA, JAA, Eurocontrol,
ICAO…
Medium term - ATA CDAH priorities

Redesign of existing non-precision approaches to accommodate
VNAV

Altitudes at precision FAF’s

Unnamed step-down fixes

Waypoints on EFIS but not in database or charts

Waypoint names longer than five characters

Duplicate navaid and waypoint identifiers

Different altitude for same point on STAR’s and approaches

Magnetic variation tables used in course calculations

VNAV angle depiction on charts
Longer term - goals

Fully resolve the disconnect between :
 the
procedure design by the Airspace Planner,
 the
coded description in the navigation database,
 and
the way it is displayed and flown by the FMS

End-to-end certified process with integrity guidelines
and criteria

A worldwide, common process with Airworthiness
Authorities involvement under an ICAO mandate
Longer term - recommendations

Publication of a single standard/language for procedure
design, database coding, and FMS
 Reduced ARINC
 Improved

424 set
charts-database-FMS compatibility
Design of “FMS-friendly” procedures
 Publication
of these procedures using FMS compatible
language (in addition to charts)

Publications of standards for navigation database
integrity and certification
Longer term - common language

Comprehensive worldwide commonality requires rules at
ICAO level

A common coding Standard should be :
 clearly
defined,
 including
rules for use by both the aircraft and the RNAV
Airspace Planner,

 the
minimum capability of any "FANS RNAV system”,
 the
maximum set usable by the RNAV Airspace Planner
This would ensure a unique unambiguous coding of
routes and procedures
Longer term - FMS friendly procedures

Use only fixed, named waypoints

For straight segments use only TF legs

For large course changes (>30°) use RF legs

Use only fly-by waypoint transitions (no overfly)

Put a waypoint at each vertical path change

Use descent gradients between 2.5° and 3.5°

Start the missed approach at or before the runway

Use same waypoint names and approach path for all approach types
to a given runway

Use unique waypoint names (max 5 characters)
Longer term - integrity

Integrity must concern the entire process, from
procedure design to the loading of the FMS

Ultimate goal should be a fully digital process

Process should be under direct supervision of airspace
management authorities

Worldwide implementation requires ICAO rules
End of presentation :
Any question?