pyarinc — ARINC 717 / ARINC 767 decoding library

pyarinc is a modern, typed Python library for decoding ARINC 717 and ARINC 767 flight‑data recorder formats. It provides a clean architecture, deterministic bit‑extraction utilities, configuration parsing (PRM/VEC), and end‑to‑end decoding into pandas DataFrames.

The library is designed for analysis pipelines, automated QA tooling, and research workflows that require reliable, test‑covered decoding of FDR/QAR data.

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Installation

The package is not published on PyPI. Install locally:

Local install

pip install .

Editable install (recommended for development)

pip install -e .

Install with test dependencies

pip install -e .[test]

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Testing

Run the full test suite:

pytest

or

pytest -vv

Tests cover:

• Bit extraction (717/767, MSB‑first, cross‑byte)
• Data‑type decoding (BNR, BCD, DISCRETE, PACKED, CHAR/ASCII, UTC, COB)
• Frame reconstruction (717) and frame parsing (767)
• Scheduling and superframes
• PRM/VEC parsing
• End‑to‑end decoding for both ARINC 717 and ARINC 767

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Capabilities

ARINC 717

• Detects aligned and bitstream formats
• Converts bitstream → aligned frames
• Reconstructs frames, subframes, and superframes
• Decodes BNR, BCD, DISCRETE, PACKED, CHAR/ISO, UTC
• Applies rate‑based scheduling and superframe rules
• Produces time‑indexed parameter values

ARINC 767

• Frame boundary detection (sync word, header, trailer)
• Timestamp extraction with wrap‑around handling
• Parameter extraction using absolute bit indexing
• VEC/PRM‑based configuration (word, bit offset, length, rate)
• Full data‑type support:
  • BNR (signed/unsigned)
  • BCD
  • DISCRETE
  • PACKED BITS
  • CHAR / ASCII
  • UTC
  • COB (Computed On Board) with formula evaluation
• Scheduling:
  • Timestamp‑based time axis (primary)
  • Rate‑based scheduling (fallback, 717‑compatible)
• DataFrame output with time, parameter_name, value, frame_index, frame_id, valid

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Configuration Support

The library parses PRM and VEC formats, including:

• subframe index (717)
• word index and bit offset
• bit length
• rate
• superframe index (717)
• scale and offset
• ARINC 767 fields:
  • frame_id_767
  • COB formulas

JSON and text formats are supported.

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Workflow

Typical decoding flow:

1. Load raw data (aligned, bitstream, or ARINC 767 frames)
2. Convert bitstream to aligned frames if needed (717)
3. Load PRM or VEC configuration
4. Decode parameters using scheduling and superframe rules
5. Produce a pandas DataFrame

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Reference Source

This project is a clean rewrite inspired by the decoding logic in the original FlightDataDecode repository:

https://github.com/osnosn/FlightDataDecode

pyarinc re‑implements the core logic with a modern architecture, strict typing, and full test coverage. No legacy scripts or .dat formats are included.

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Notes

• No Lua integration
• No custom .dat format
• No print() statements — uses Python logging
• Fully typed (Python 3.12+)
• Deterministic, testable, modular design