arinc 424 intro

RNAV1Federal Aviation

AdministrationJuly 14, 2008

WAAS PRINCIPLES

ARINC 424

REPORTING

WAAS FLIGHT INSP

WAAS REFERENCE PLANES

PRE-FLIGHT PREPARATION

FMS LEG PROGRAMMING

WAAS

INTERFERENCE CHECKAFIS RECORDINGAFIS SET-UP

AFIS / CDU OPSNAV SOURCE CONFIG.ANNUNCIATIONS

PILOT SECTION

MISSION SPECIALIST SECTION

INTRODUCTION

TERMS

Click on red block to link to that training.

Presented to: Flight Inspection Crewmembers

By: AJW-3310

Date: July 14, 2008

Federal AviationAdministrationWide Area

Augmentation System (WAAS)

ARINC 424

Coding



What is ARINC 424 CODING?

INITIAL FIX

RETURN

INITIAL FIX

MSG

ALT CONST

IDENTIFIER SEGMENT

COPOM

COPOM ACCEPT

------

FINAL APPR



ARINC 424 Coding• A computer language leg type used in a

flight management system to define how the procedure will behave at a given time.

• The description of the leg types introduces you to the “Path/Terminator” concept. – The path logically describes how the aircraft gets to

the terminator, by flying a heading, track, course, etc.

– The terminator is the event or condition that causes the system to switch to the next leg.



ARINC 424 Coding

• The description of the leg types introduces you to the Path/Terminator” concept (cont’d). – When a clearance is issued, like, “Fly

runway heading to 2,000 feet”, you have applied the path/terminator concept.

– The path, rather obviously, is runway heading. The terminator is 2,000 feet, where the pilot will “sequence legs” and do something else.




• Each of the different legs are identified by a 2-letter mnemonic. – First letter identifies the path– Second letter identifies the terminator. – Mnemonics do get a bit obscure in some of these

cases. The example cited previously- “Fly runway heading to 2,000 feet” – would be coded in the data base as a “Heading-to-Altitude” – described as a VA leg (“V” as a “Vector”, since the letter “H” is used to describe hold legs).




• Each of the different legs are identified by a 2-letter mnemonic (cont’d). – There are 2 required system inputs:

• The compass and altimeters. • As a leg is implemented in the FMS, the system reads the

compass system, and provides the autopilot or flight director with a steering command that will null out any deviation from the desired heading.

• The system will also be monitoring its baro-altitude input (QNH), then sequence legs when the terminating altitude has been reached.



• The following slide depicts the sixteen enroute leg types you should familiarize yourself with.




Enroute Legs

(VA) Heading To Altitude

(VD) Heading To DME

(VI) Heading To Next Leg Intercept

(VM) Heading To Manual Termination (VR) Heading To a Radial

(CA) Course To Altitude

(CD) Course To a DME

(CI) Course To Next Leg Intercept

(CR) Course To a Radial

(CF) Course To a Fix (TF) Track To a Fix (DF) Direct To a Fix

(FA) Fix To Altitude (FC) Fix To a Distance on Course

(FD) Fix To a DME Termination

(FM) Fix To a Manual Termination



Enroute Legs

• However, there are primarily 5 legs that you will be using on a daily basis. – The VA, CF, TF, DF, and CA Enroute leg types.

• As Flight Procedures Standards Branch solves ARINC 424 coding issues, more legs may be used. We will discuss each of them and explain the “Path and Terminator.”





(CF) Course To a Fix

(TF) Track To a Fix

(DF) Direct To a Fix

Enroute Legs




(VD) Heading To DME

Enroute Legs

•A VA leg is typically used as the first leg in a departure. The

path is the 090º heading to the terminator (8000’).

•The VD leg Path is a 090º heading to the terminator of a unspecified point on the DME arc, that has been programmed into the database.



(VR) Heading To a Radial


Enroute Legs

•The VR leg Path is the 090º heading. The terminator is a specific point on a VOR radial where the heading takes it.

•This CA leg Path is the 080º course. The terminator is a specific altitude, in this case 6000 feet.



(CD) Course To a DME (CI) Course To Next Leg Intercept

Enroute Legs

•This CD leg Path would be a 080º course. The terminator is a specified DME distance.

•The CI leg Path is the 090º course. The termination is the interception of the 070º radial.



(CR) Course To a Radial

(CF) Course To a Fix

Enroute Legs

•This CR leg Path is a 090º course. The terminator is when the course crosses the 125º radial.

•The CF leg Path is a 080º course to a specified latitude and longitude.



(TF) Track To a Fix

Enroute Legs

This is a “track to fix” leg. The path and terminator are latitude/longitudes. This leg type will be used for GPS approaches and airway segments. This is your “great circle track” between 2 defined waypoints. It is the easiest to implement as the only thing the pilot has to do is input lat/long’s for the database.



(DF) Direct To a Fix

Enroute Legs

This is a diagram of a DF leg. The aircrafts path is the present position. The terminator is to a specific waypoint. This is used when ATC gives the clearance, “go direct” or you request present position to a specific point i.e. fix, navaid, etc.



(FA) Fix To Altitude

9 NM

(FC) Fix To a Distance on Course

Enroute Legs

•This FA leg Path begins at a fix and, via a specific course (105º), will be continued until the specified altitude is reached.

•An FC leg Path begins at a defined fix with a course outbound. The fix must be in the database but can be a VOR, intersection, etc. The terminator is the specific distance on the outbound course.



(FD) Fix To a DME Termination (FM) Fix To a Manual Termination

Enroute Legs

•This FD leg Path is a fix, and the terminator is DME distance. The DME does not necessarily need to be from the reference fix. The DME fix is not required to lie on the course from the path fix.

•The FM fix Path is a course from a fix. The termination is manually selected. Since you manually select the termination point there will be no automatic leg sequencing.



(AF) Arc To a Fix

ARINC Legs

•We will now discuss the 2 types of arc legs that ARINC 424 coding provides:

- Arc to Fix leg (AF)

-Radius to Fix leg (RF)

-They appear redundant but, they serve two different purposes.



(AF) Arc To a Fix

ARINC Legs

•The AF leg is a standard DME arc which requires a navaid. The path is the arc and the terminator is the specified radial/DME that you desire. In this case it is the 030º/8 DME.

•There are two things to remember.

- Minimum radius is 4.0 nm.

-Arc radius resolution is 0.1 nm.



(RF) Radius To a Fix

ARINC Legs

The RF leg Path and terminator are “hard fixes”. However, they do not require a navaid at the arc’s origin. It is referred to as the “precision arc” leg because it’s resolution is 0.001 nm, (6’). Its primary use is for curved-path approaches.



• There are three different types of holding legs that we will be discussing. – Hold to Fix (HF)– Hold to Altitude (HA) – Hold to Manual Termination (HM)

Holding Legs



Holding Legs

• The HF leg provides one holding orbit and sequence to the next leg once it has completed one circuit. This is used when a holding pattern is used in lieu of a procedure turn on an approach.

• The HA provides for a climb in the holding pattern. Upon reaching the programmed altitude, the holding circuit will be completed and the sequenced leg will begin the course to the next waypoint.

• The HM leg requires the pilot to manually program the next sequenced leg.



(HF) Hold To a Fix

Holding Legs(HA) Hold To Altitude

(HM) Hold To a Manual Termination



WAAS PRINCIPLES

ARINC 424

REPORTING

WAAS FLIGHT INSP

WAAS REFERENCE PLANES

PRE-FLIGHT PREPARATION

FMS LEG PROGRAMMING

WAAS

INTERFERENCE CHECKAFIS RECORDINGAFIS SET-UP

AFIS / CDU OPSNAV SOURCE CONFIG.ANNUNCIATIONS

PILOT SECTION

MISSION SPECIALIST SECTION

INTRODUCTION

TERMS

Click on individual blocks to link to that training.

arinc 424 intro

Documents

federal aviation

mission specialist

leg types

fly runway

va leg

leg intercept

sequenced

arinc 424