Cabin electronic equipment
Cabin electronic equipment STC installation support
This support readies the installation evidence for cabin electronic equipment ahead of an STC approval, where the concern turns from the qualified unit to how it lives inside a particular cabin. A modifier holding or pursuing the STC runs it when the power connection to the aircraft, the wiring installation, the flammability of what surrounds the unit, and any installation limitations have to reconcile to the type-certified aircraft. The work reads the installation data, marks where an install claim lacks a drawing or analysis, and orders the gaps for closure. You receive an installation-specific gap list, a trace to the approval basis, and a closure sequence.
When this review is needed
- A qualified cabin unit is being installed under an STC and the installation power and flammability evidence needs checking before approval.
- The unit connects to a specific cabin power source and the load addition to that bus has to be shown acceptable.
- Surrounding monuments, panels, or trim fall inside the fire-zone reasoning and their flammability must be reconciled for this cabin.
- Installation limitations from the unit's qualification have to be carried into the aircraft approved documentation.
The problem
A cabin STC installation adds a qualified unit to a cabin that was already certified without it, and the certification basis wants proof the addition did not disturb what was approved. Power is the first pressure point: the unit loads a specific bus, and that bus already has a documented budget the installation has to stay inside. Flammability is the second: the unit and everything mounted around it sit in a cabin whose fire behavior was substantiated as an assembly, so a new panel, bracket, or trim piece reopens that reasoning. These two questions get answered against the cabin, not the unit, and the unit's qualification data cannot answer them.
What gets reviewed
- Load addition to the specific cabin bus against that bus's documented power budget
- Wiring installation, routing, and separation for the unit within the target cabin
- Flammability of installation-added materials and their effect on the cabin's substantiated fire behavior
- Installation limitations from the unit's qualification carried into the aircraft documentation
- The compliance matrix mapping each installation requirement to cabin-specific substantiation
- Traceability from the unit's qualified conditions to the installation evidence that satisfies them
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 load added to the cabin bus keeps that bus inside its documented power budget
- Wiring routing and separation for the unit resolve to an installation drawing and a verification record
- Flammability of every installation-added material is substantiated for its location in this cabin
- Installation limitations from qualification appear in the aircraft documentation the approval will carry
- Each installation-requirement line in the matrix points to cabin-specific substantiation, not the unit's qualification data
Evidence normally required
- The STC certification basis and the means-of-compliance statement for the installation
- The cabin unit's qualification data and its installation conditions and limitations
- The target cabin's electrical load schedule and the affected bus power budget
- Installation drawings, wiring diagrams, and the list of installation-added materials
- The current installation compliance matrix and the affected aircraft documentation
Common discrepancies
- A load addition that pushes the cabin bus past the budget documented for that installation
- An installation-added panel or bracket whose flammability was never substantiated in place
- Installation limitations present in the unit's qualification but absent from the aircraft documentation
- A wiring separation claim carried from the unit's qualification rather than shown for this cabin routing
What is at stake
An installation that pushes a cabin bus past its documented budget, or introduces a material whose flammability was never substantiated in place, either draws a finding at approval or ships with a limitation. Both power and flammability gaps tend to surface late because the installation team assumes the qualified unit carries its own answer, and unwinding a bus-loading or fire-zone issue near approval means reopening the electrical or interior design under schedule pressure.
How the work runs
Read the conditions
Extract the unit's power and flammability installation conditions and limitations as the constraints the cabin install must meet.
Check the bus budget
Confirm the load added to the target cabin bus stays inside its documented power budget.
Reconcile the fire reasoning
Show every installation-added material is substantiated in place against the cabin's fire behavior.
Sequence for closure
Split electrical from materials items, order by approval impact, and deliver the plan.
What the buyer receives
- An installation-specific gap list ordered by approval impact
- A trace map from the unit's qualified conditions to the cabin substantiation that meets them
- A closure sequence separating electrical items from flammability and materials items
Who uses the output
- Installation engineers reconciling the unit's power and flammability conditions with the cabin
- Certification engineers assembling the STC installation compliance data
- Program leads deciding whether a routing change or a limitation clears an open item
How the work fits into the transaction or program
This review bridges the cabin unit's qualification and the STC installation approval. It confirms the installation stays inside the bus budget, keeps the cabin's fire substantiation intact, and carries the unit's limitations forward, so the approval reads from cabin-specific evidence rather than qualification data borrowed out of context.
Start with a single asset
Confirm requirements map to substantiating evidence.
Aircraft-specific considerations
The evidence burden depends on the cabin: the available power budget on a target bus, and how much of the surrounding interior falls inside the fire-zone reasoning, differ by aircraft and by how the cabin was previously configured. The review scopes the load and flammability checks to the actual target cabin and its documentation rather than assuming a generic installation.
Regulatory limits
This is an installation-evidence readiness review. It makes no airworthiness determination, issues no STC or approval, and does not represent the modifier to the authority. The FAA or EASA is the sole party that approves the installation and its data.
What this review does not cover
- Designing the electrical installation, wiring, or interior modification
- Performing the flammability substantiation or the bus-loading analysis
- Filing the STC application or engaging the authority for the modifier
Specific to this review
- A cabin bus carries a documented power budget, so a qualified unit can still fail the install by exceeding it.
- Cabin fire behavior is substantiated as an assembly, so an added bracket or panel reopens flammability that the electronics never touched.
- Wiring separation shown in the unit's qualification does not carry to a specific cabin routing without its own evidence.
- Power and flammability install gaps surface late because teams assume the qualified unit answers them, when the answer is against the cabin.
Sources
U.S. Government (eCFR). Type certificates, STCs (Subpart E), TSO authorizations (Subpart O), PMA (Subpart K), and export airworthiness approvals (Subpart L).
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.
SAE International. Development assurance process at aircraft and system level, including requirements capture and validation.
Frequently asked questions
The unit is qualified for flammability already. Why re-examine it for this cabin?
Qualification covers the unit's own materials. The STC has to protect the cabin's fire behavior, which was substantiated as an assembly. Any bracket, panel, or trim the installation adds around the unit sits inside that reasoning and needs its own in-place substantiation, so the review checks installation-added materials against the target cabin.
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.
Talk through the aircraft, records, evidence, deadline, and next useful step.