STC programs
STC certification data support for modifiers and suppliers
STC certification data support helps an aircraft modifier or equipment supplier assemble the installation-level data a supplemental type certificate submission depends on. It is used by teams running an STC program who need the substantiating package put in order before authority engagement. It reviews the certification plan, the installation compliance data, the substantiation behind each affected area, and the instructions for continued airworthiness. You receive a gap assessment against the project certification basis and a structured data set ready for review.
When this review is needed
- An STC project is moving toward authority engagement and the installation data has to be ordered from the basis down.
- An installation touches several disciplines and the substantiation has to be pulled into one coherent package.
- An STC program needs the instructions for continued airworthiness drafted and traced to the change being approved.
- A team wants an outside read of the substantiation before it commits to a submittal date.
The problem
An STC turns on the substantiation behind the change, and that substantiation tends to live in scattered analyses, test reports, and drawings that were produced as the design matured. The certification plan promises coverage the package never quite delivers, the instructions for continued airworthiness lag the design, and an affected-area assessment that was right at concept no longer matches what was built. By the time the authority opens the package, the gaps surface as questions.
What gets reviewed
- The certification plan and the compliance approach it commits to for each affected area
- Installation compliance data covering structures, electrical load, and systems integration as applicable
- Substantiation reports behind each claim of compliance for the modification
- Requirements traceability from the change definition through verification
- Instructions for continued airworthiness produced for the change
- Affected-area and change-impact assessment against the unmodified type design
Scope this review
Tell us the asset, the event, and the evidence in scope, and we will outline a focused first engagement.
Identify what is missing against the means of compliance.
What gets validated
- The certification plan's promised coverage matches what the substantiation package actually contains
- Each affected area carries substantiation that supports the compliance claim made for it
- Electrical load analysis and systems integration data reflect the configuration as installed
- Instructions for continued airworthiness exist for the change and trace to the parts and tasks they cover
- The change-impact assessment captures every area the modification touches
- Verification evidence is present for requirements marked as met by test or analysis
Evidence normally required
- The certification plan and the project certification basis
- Installation drawings and the configuration definition for the modification
- Substantiation analyses and test reports assembled so far
- Any draft instructions for continued airworthiness
- Open authority questions if the project is already in engagement
Common discrepancies
- Substantiation that lags the as-built configuration after late design changes
- Affected areas the change-impact assessment missed
- Continued-airworthiness instructions that are incomplete or untraced to the change
- Electrical load data that does not reflect the equipment actually installed
- Compliance claims in the plan with no substantiating report behind them
What is at stake
When the substantiation does not hold together, authority questions multiply and the project absorbs cycles it did not budget for. Each round pulls engineers back onto closed work, the installation slips its slot on the aircraft, and the cost of the modification climbs while the asset waits.
How the work runs
Read the plan against the basis
Confirm the certification plan's compliance approach covers the project certification basis and the affected areas.
Order the substantiation
Index each affected area to its substantiation and find where the package falls short of the claim.
Trace the change
Map the change definition through verification and check the change-impact assessment for missed areas.
Close the package
Produce a gap assessment and a prioritized closure list covering substantiation and the ICA.
What the buyer receives
- A gap assessment against the project certification basis and the certification plan
- An ordered substantiation package indexed to each affected area
- A traceability view from the change definition through verification
- A prioritized list of the data and ICA needed to close the package
Who uses the output
- Certification leads preparing the authority submittal
- Engineering teams closing substantiation and ICA gaps
- Project management sequencing the remaining work against the aircraft slot
How the work fits into the transaction or program
The work supports the modifier's own STC program. It puts the substantiation in order ahead of authority engagement so questions land earlier and resolve faster, and it leaves the team with a package a fresh reviewer can follow from basis to ICA.
Start with a single asset
Reduce finding cycles by checking the package first.
Regulatory limits
Endeavor Elements supports the applicant's STC data. It does not issue a supplemental type certificate, make compliance findings on the authority's behalf, or determine that an installation is approved. The applicant and the certifying authority keep their roles.
What this review does not cover
- Issuing or holding the STC or any design approval
- Acting as the authority or making official compliance findings
- Producing the engineering design or the installation drawings
Specific to this review
- An STC approves a change to an existing type design, so the substantiation has to address the affected areas of that design, not the whole aircraft.
- The instructions for continued airworthiness are part of the approved data and are a frequent late item, because they depend on a configuration that keeps moving until the design freezes.
- Electrical load analysis is a recurring weak point on avionics installations, because the load picture changes every time equipment is added or relocated late in the program.
Sources
U.S. Government (eCFR). Type certificates, STCs (Subpart E), TSO authorizations (Subpart O), PMA (Subpart K), and export airworthiness approvals (Subpart L).
Federal Aviation Administration. STC application process, certification basis, and continued airworthiness obligations of an STC holder.
European Union / EASA. EASA design and production certification, STCs, ETSO authorizations, and EASA Form 1 release.
RTCA. Environmental qualification test categories and procedures referenced by TSO and equipment qualification.
Frequently asked questions
Does an STC data review cover the whole aircraft?
No. An STC approves a change to an existing type design. The review concentrates on the affected areas of that design and the substantiation behind the change, not the unmodified parts of the aircraft.
Can you help draft the instructions for continued airworthiness?
The review identifies where the instructions for continued airworthiness are missing or untraced to the change and what they need to cover. The applicant's engineering authors and owns the ICA as part of the approved data.
Relevant glossary terms
Related pages
Where this fits
Talk to an engineer who has done this work
We will walk through your current state, the records or evidence involved, and a scoped first engagement.
Walk through your situation with an engineer who has done this work.