# Airworthiness Liaison

> Use when you must manage DO-178C airworthiness and certification liaison for an airborne software item: confirm the certification basis items with evidence, score stage-of-involvement audit readiness against the software level threshold, and track open liaison items to closure before authority audits. Produces the certification-basis coverage account, the SOI readiness verdict, and the open-item action flags that keep the certification plan on schedule. Trigger: airworthiness liaison, certification liaison, soi audit, certification basis, authority communication, audit readiness.

- Skill: `ashfordeou/airworthiness-liaison` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add ashfordeou/airworthiness-liaison`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ashfordeou/airworthiness-liaison/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- License: Apache-2.0
- Author: ashfordeOU (https://skillmd.com/u/ashfordeou)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/ashfordeou/airworthiness-liaison

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# DO-178C Airworthiness Liaison (avionics/do178c/airworthiness-liaison)

Use when the task is DO-178C airworthiness and certification liaison:
certification-basis coverage, SOI audit readiness, and open-item
tracking with the certification authority.

## Domain quick reference

- Certification basis: the airworthiness requirements the software
  item must satisfy (airworthiness regulations plus the accepted
  means of compliance); each basis item needs evidence.
- Stage-of-involvement (SOI) audits: the authority audits planning,
  development, verification, and configuration management artifacts;
  readiness is the fraction of required evidence that is present.
- Readiness thresholds are project-defined and scale with the
  software level: levels A and B demand full evidence, lower levels
  tolerate small gaps.
- Open liaison items (issue papers, audit findings) must close
  before the certification plan can complete.

## Workflow

1. Collect the certification basis items and their evidence status.
2. Build the coverage account with cert_basis_coverage.
3. Map required evidence to the software level and score SOI
   readiness with soi_readiness.
4. Track open liaison items with liaison_action.
5. Gate the next audit on readiness and open-item closure.

## Pitfalls

- Counting basis items without evidence as covered.
- Applying a level A readiness bar to level D work (and the reverse).
- Letting open items ride through audits unclosed.

## Behavior contract (gate 3)

The certification-basis, readiness, and action logic is exercised by
the gate 3 contract test: scripts/test_airworthiness_liaison.py
against scripts/airworthiness_liaison_logic.py (stdlib unittest,
offline). Run:
python3 scripts/test_airworthiness_liaison.py

## Compliance

- Standards referenced, not reproduced: DO-178C and ARP4754A text is
  proprietary (RTCA/SAE); summary-only per standards-map.yaml and
  brief 06. No objective tables or appendix text.
- compliance: STANDARDS-REF, gated: false.