ARINC 424

ARINC – Aeronautical Radio Inc. , a corporation of a variety of stockholders such as airlines, aircraft manufactures and other air transport companies. Arinc activities includes operation of land radio stations, the allocation and assignment of frequencies and the exchange of technical information.
AEEC- Airlines Electronic Engineering committee.
ARINC 424 is a specification for Navigation System Data Buses.
DEF: is a standard for the preparation and transmission of data for assembly of airborne navigation system data buses.
Arinc424 speed and altitude limits:
According to ARINC 424 speed limitations can be coded in different ways by using different path terminators. Inorder to achieve consistency all speed restrictions in RNAV procedures should be applied at specific waypoints. Speed restrictions that are only applied during specific time periods are not coded in database. Some legacy systems can only process speed restrictions in combination with an altitude restriction.
The altitude description field will designate whether a waypoint should be crossed “at”, “at or above” or “at or below” specified altitudes.
The conditional termination altitude can be coded in columns 90 through 95 of the SID record. If a “+”, “-” or blank is coded in the altitude description field, input of a second altitude must imply a conditional altitude termination.
If a published take-off requires a turn greater than 15 degrees from the runway heading without an altitude specified before the turn.....a CA, VA, or FA on the runway heading to an altitude of 400 feet (or as specified by source) must be coded before the turn or as first leg of the departure.
arinc 424 waypoint, navaid, fix coordinates:
The geographic position of waypoints, intersections, navaids, runway thresholds etc. is defined in the latitude/ longitude fields.
Nine alpha/numeric characters define the latitude in degrees, minutes, seconds, tenth of seconds and hundredths of seconds:
N45562518
Ten alpha/numeric characters define the longitude in degrees, minutes, seconds, tenth of seconds and hundredths of seconds:
E015523622.
This resolution reflects the airlines desire for the use of best available data.
The Path and Terminator concept was developed to permit coding of terminal area procedures, SIDs, STARs and approach procedures without proliferating the number of waypoints. The two elements Path and Terminator prescribing the way in which a path is to be flown and how the path is to be terminated.
Over the years and in particular with the introduction of RNAV new leg types were added.
Currently, the ARINC 424 document describes 23 path terminators.
Certain limitations such as leg sequence or fly-by/ fly-over rules must be considered by procedure designers.
Database suppliers must be accomplished using path/terminators most appropriately reflecting the government source.


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AVIATOR