TSO flight deck
TSO compliance evidence support for flight-deck equipment
This support maps a flight-deck equipment item's evidence to the Technical Standard Order it is being approved against. It is run by the equipment supplier assembling a TSO authorization application or answering a finding on one. The work checks coverage of the minimum performance standard the TSO invokes, the DO-160G environmental qualification and DO-178C software levels the article requires, any deviations sought, and the line between what the TSO article covers and what installation approval must handle separately. You get a standards map keyed to the TSO and its invoked standards, a ranked evidence gap list, and a closure sequence.
When this review is needed
- A TSO authorization application for a flight-deck item is being assembled and its evidence needs mapping to the invoked standards.
- An authority raised a finding that the minimum performance standard is not fully covered by the test evidence on file.
- A deviation from the TSO is contemplated and its justification and scope have to be structured.
- Reviewers are treating installation-level behavior as a TSO gap and the article boundary has to be drawn clearly.
The problem
A TSO approves an article against a named minimum performance standard, and the evidence has to line up test for test against that standard, not against the supplier's own qualification plan. Flight-deck items get tangled because so much of their behavior only appears once installed, and reviewers push installation-level questions back onto the TSO article where they do not belong. The package then carries evidence that proves the box works in a cockpit while leaving a paragraph of the performance standard uncovered, and the mismatch is invisible until someone reads the two side by side.
What gets reviewed
- Coverage of the minimum performance standard the TSO invokes, clause by clause
- DO-160G environmental qualification matched to the TSO environmental categories
- DO-178C software levels appropriate to the article's functions
- Deviations sought from the TSO with their justification and scope
- The boundary between TSO article evidence and installation approval
- Marking, nameplate, and data requirements the TSO article carries
What gets validated
- Each clause of the minimum performance standard maps to specific test or analysis evidence
- DO-160G categories tested match those the TSO and the intended installation require
- Software levels align with the article functions and the invoked standard
- Every deviation is documented with a justification the authority can evaluate
- Installation-level behavior is kept out of the article evidence and flagged for separate approval
Evidence normally required
- The applicable TSO and the minimum performance standard it invokes
- DO-160G qualification test reports for the article
- DO-178C plans and software level records for the article functions
- Any deviation requests and their supporting rationale
- The article's marking, nameplate, and data plates as designed
Common discrepancies
- A clause of the minimum performance standard with no matching test evidence
- DO-160G categories that do not cover the intended installation environment
- Installation-level behavior substantiated inside the TSO article evidence
- A deviation applied without a documented justification the authority can weigh
What is at stake
A TSO package that does not cover every clause of its minimum performance standard draws a finding that the article is not fully substantiated, and closing it means new testing against the standard rather than the plan. When installation behavior is allowed to bleed into the article evidence, the authorization scope blurs and the supplier ends up owning substantiation that belongs to the installer, which is slower and more expensive to unwind late.
Move from findings to resolution
Identify gaps against the means of compliance.
How the work runs
Line up the standard
Map each clause of the invoked minimum performance standard to the article evidence that covers it.
Match the environment
Confirm DO-160G categories and software levels fit the article and its intended installation.
Structure the deviations
Document each deviation with a justification the authority can evaluate on its terms.
Draw the article boundary
Separate installation-level questions from the article evidence and sequence the remaining gaps.
What the buyer receives
- A standards map keyed to the TSO and its invoked minimum performance standard
- A ranked evidence gap list distinguishing article gaps from installation questions
- A closure sequence identifying which clause to substantiate first
Who uses the output
- Certification leads assembling the TSO authorization application
- Test and systems engineers matching evidence to the performance standard
- Compliance managers responding to a TSO finding on the flight-deck article
How the work fits into the transaction or program
This review sits at the article level, below the installation approval an STC or type change will handle. It confirms the flight-deck item's evidence covers its TSO and the invoked standard cleanly, so the authorization holds on its own and the installation approval can build on a settled article rather than reopening it.
Start with a single asset
Confirm requirements trace through verification.
Jurisdiction-specific considerations
The FAA issues a TSO authorization and EASA the equivalent ETSO, and while they often invoke the same performance standard, their deviation handling and article-data expectations differ. The map notes where evidence built for one authorization needs supplement to carry into the other so a dual approval is not derailed by a paperwork gap.
Regulatory limits
This work maps and checks the article evidence against the TSO and its invoked standards. It does not grant a TSO authorization, approve any deviation, or make an airworthiness determination on the installed article. Those decisions rest with the applicant and the certifying authority.
What this review does not cover
- Running the DO-160G or performance-standard testing itself
- Substantiating the installation of the article on a specific aircraft
- Any determination that the flight-deck article is airworthy or approvable
Specific to this review
- A TSO approves the article, not its installation, so evidence that proves the box works in a cockpit can still miss a clause of the performance standard.
- The most common flight-deck TSO error is letting installation-level behavior bleed into the article evidence, which blurs the authorization scope.
- A deviation is only as strong as its documented justification; an undocumented one reads as an uncovered clause of the standard.
Sources
U.S. Government (eCFR). Type certificates, STCs (Subpart E), TSO authorizations (Subpart O), PMA (Subpart K), and export airworthiness approvals (Subpart L).
RTCA. Environmental qualification test categories and procedures referenced by TSO and equipment qualification.
RTCA. Objectives and lifecycle data for airborne software assurance, by design assurance level (DAL A-E).
Frequently asked questions
Why is installation behavior a problem in a TSO package?
A TSO authorizes the article against a performance standard, not its installation on an aircraft. When installation-level behavior is substantiated inside the article evidence, the authorization scope blurs and the supplier ends up owning substantiation that belongs to the installer. The review keeps that boundary clean so the article approval stands on its own.
Relevant glossary terms
Related pages
Where this fits
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