I'm particularly interested in Approach procedures, but I guess it applies for RNAV procedures in general.
On one side, the national Air Navigation Service Provider (ANSP) is responsible for the design of the procedure. The procedure charts are usually available as PDF files through AIP website (e.g. the terminal procedures available at FAA).
On the other side, the RNAV procedure is coded in binary format inside aircraft's FMS. The airborne databases that can be directly loaded to the FMS are provided by external companies (Jeppesen, Lufthansa, Navigraph).
What happens between those two points is kind of puzzling for me.
I know of ARINC-424 standard for aircraft navigation data that is used for "preparation and transmission of data". Then there is AIRAC cycle which as I understand provides fixed dates for any changes to become effective.
The questions are:
- Who takes responsibility that the database being sold to airline or any user reflects the original procedure published by ANSP?
- How does the coding process look like. Is it based on PDF charts or there is another exchange format available (e.g. AIXM)?