Certification evidence
Transponder and ADS-B register verification evidence review for DO-178C
This review is for avionics suppliers, operators, MROs responsible for transponder and ADS-B register verification. It is triggered by aDS-B/transponder installation verification. EE checks register-to-source mapping, data-source integrity substantiation, register-loading test results, plus the governing plan or application, against DO-178C. Discrepancies include missing source records, mismatched configuration, unsupported assumptions, or SIL/SDA broadcast values not backed by the actual source integrity. Output includes Transponder and ADS-B register verification exception register, Claim to evidence map, Reviewer question list.
When this review is needed
- A new article, software load, or installation is moving into certification review.
- Quality control needs a repeatable list of ready and open records.
- Internal teams need a supplier request list tied to evidence gaps.
- The buyer wants a defensible package before committing the claim.
The problem
Certification risk sits in the gap between the claimed basis and the records in the folder. With transponder and ADS-B register verification, SIL/SDA broadcast values not backed by the actual source integrity can stay hidden until the exact source record is requested.
What gets reviewed
- Review register-to-source mapping against the configuration, installation, or claim under review.
- Compare data-source integrity substantiation against the configuration, installation, or claim under review.
- Trace register-loading test results against the configuration, installation, or claim under review.
- Challenge tie to the installed navigation against the configuration, installation, or claim under review.
- Reconcile air-data sources. against the configuration, installation, or claim under review.
What gets validated
- Pass check: register-to-source mapping must match the released configuration and the claimed means of compliance.
- Configuration check: data-source integrity substantiation must match the released configuration and the claimed means of compliance.
- Trace check: register-loading test results must match the released configuration and the claimed means of compliance.
- Rationale check: tie to the installed navigation must match the released configuration and the claimed means of compliance.
- Closure check: air-data sources. must match the released configuration and the claimed means of compliance.
Evidence normally required
- Controlled register-to-source mapping
- Released data-source integrity substantiation
- Signed register-loading test results
- Current tie to the installed navigation
- Archived air-data sources.
- Supplier plan revision
Common discrepancies
- Gap: sIL/SDA broadcast values not backed by the actual source integrity.
- Mismatch: position source not the qualified GNSS.
- Unsupported claim: register content correct on the bench but wrong once installed.
What is at stake
A weak package can convert a planned review into a long question log. If position source not the qualified GNSS, the program may need new evidence before the claim can proceed.
Move from findings to resolution
Identify gaps against the means of compliance.
How the work runs
Frame Mops Transponder
Confirm the exact event, affected file set, buyer role, and decision standard before any register-to-source mapping is treated as sufficient.
Trace Verification Review
Walk the named evidence from index entry to source artifact and mark where the trail supports, conflicts with, or fails to answer the page-specific question.
Sort Evidence 178c
Group exceptions by closure route: document retrieval, data correction, engineering disposition, authority response, or contractual decision.
Package Every Data
Deliver the exception list, evidence map, and owner sequence in a form that can move directly into remediation, submittal cleanup, or transaction negotiation.
What the buyer receives
- Transponder and ADS-B register verification exception register
- Claim to evidence map
- Reviewer question list
- Closure action plan
Who uses the output
- avionics engineer assign closure actions from the exception register.
- certification liaison use the map to locate source evidence.
- installation engineer decide what can proceed and what must wait.
How the work fits into the transaction or program
Does the transponder/ADS-B register-loading evidence prove each broadcast parameter comes from the correct, qualified source at the right integrity, because ADS-B and Mode S register content is where installation-level errors hide even when the transponder itself is qualified. The evidence set centers on the register-to-source mapping (position, velocity, integrity/SIL/SDA, call sign, emitter category), the data-source integrity substantiation, the register-loading test results, and the tie to the installed. The likely weak points are SIL/SDA broadcast values not backed by the actual source integrity, position source not the qualified GNSS, and register content correct on the bench but wrong once installed; Complements the transponder/TCAS product pages with the installation-level register critique. The output gives the avionics engineer a cleanup register for Transponder and ADS-B register verification before ADS-B/transponder installation verification.
Start with a single asset
Confirm requirements trace through verification.
Regulatory limits
The output supports applicant decision making and authority discussions. It does not replace required approvals, designee findings, conformity activity, or airworthiness determinations.
What this review does not cover
- Final certification decision
- Airworthiness determination
- Hardware or software redesign
- Production quality release
Specific to this review
- Configuration identity matters because evidence from another baseline may prove a different article, load, or installation.
- A useful trail names the source record, revision, owner, and closure decision for each claim.
- The exception list separates document-control cleanup from gaps that need engineering substantiation.
- The finding pattern for this page is specific: SIL/SDA broadcast values not backed by the actual source integrity changes the strength of the certification argument.
- The scope uses the Mops Transponder Register Verification question as the control point, so the review stays tied to ADS-B/transponder installation verification and the buyer decision behind it.
- The evidence starts with Register-to-source mapping and follows Review Ads Evidence 178c references until every exception has a source location and a reason code.
- The finding logic separates missing paperwork, conflicting status, stale revision data, and unsupported disposition because each class closes through a different owner.
- The timing matters for avionics engineer: the output is useful only if the unresolved items are visible before acceptance, submittal, handback, or negotiation pressure fixes the sequence.
- The boundary control keeps Certification Every Data Source questions in the records or certification lane and sends technical acceptance issues to the authorized people who own them.
- The handoff value comes from Transponder and ADS-B register verification exception register; it gives the next reviewer a precise map instead of another broad request for a better file.
Sources
U.S. Government (eCFR). Type certificates, STCs (Subpart E), TSO authorizations (Subpart O), PMA (Subpart K), and export airworthiness approvals (Subpart L).
RTCA. Objectives and lifecycle data for airborne software assurance, by design assurance level (DAL A-E).
Frequently asked questions
What makes this evidence review different from a general file audit?
The scope is tied to mops transponder register verification and to the decision named in the request. A general audit can list weak records; this pass ranks the gaps by whether they block ads-b/transponder installation verification or can be closed later without changing the decision.
What evidence has to be available before this work starts?
The starting point is register-to-source mapping, the current status source, and any index or matrix that tells reviewers where the supporting artifact should live. Missing inputs are logged as findings rather than filled with assumptions.
Who decides whether an open item is acceptable?
The review explains what the evidence supports and gives avionics engineer a closure path. Acceptance remains with the buyer, operator, authority, delegated engineer, or authorized person responsible for the underlying airworthiness or certification decision.
Relevant glossary terms
Related pages
Where this fits
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