Part 27 flight deck
Part 27 certification-basis support for normal-category rotorcraft flight-deck equipment
This support aligns flight-deck equipment to the Part 27 paragraphs that apply on a normal-category rotorcraft and checks the package against each one. A certification or engineering lead runs it while preparing a submittal or answering a finding. It covers the crew interface, the display behavior the pilot depends on, the DO-160G environmental qualification against the rotorcraft vibration and temperature environment, and the installation assumptions the equipment carries. You receive a paragraph-level standards map, a gap list keyed to the missing evidence, and a closure order weighted toward the highest-risk findings.
When this review is needed
- Flight-deck equipment developed for a fixed-wing installation is being brought onto a normal-category rotorcraft and the basis shifts to Part 27.
- An authority finding asks how the crew interface performs under rotorcraft workload and the substantiation is thin.
- The DO-160G qualification predates the rotorcraft's vibration profile and has to be checked against it.
- Installation assumptions written for another airframe need to be shown as valid on this rotorcraft.
The problem
Flight-deck equipment is often qualified once and reused across airframes, but a normal-category rotorcraft imposes a vibration and workload environment that a fixed-wing basis never tested. The crew-interface rationale, the display-behavior evidence, and the environmental reports were written against different installation assumptions, and no one has confirmed they still hold on the rotorcraft. The mismatch hides until a Part 27 finding forces it out.
What gets reviewed
- Part 27 paragraphs applicable to the flight-deck equipment and its crew-facing functions
- Crew-interface and workload assumptions checked against the rotorcraft operating context
- Display behavior in normal and degraded modes traced to substantiation
- DO-160G qualification mapped to the rotorcraft vibration and temperature environment
- DO-178C software life-cycle data checked against the assurance level the function requires
- Installation assumptions confirmed valid for this rotorcraft rather than the original airframe
What gets validated
- Each Part 27 paragraph in the basis links to a named document rather than a compliance assertion
- The crew-interface evidence addresses the rotorcraft's workload, not the cockpit the equipment was first designed for
- DO-160G vibration categories cover the rotorcraft environment, which is often more demanding than the original test
- Software assurance level matches the failure-condition classification for the rotorcraft function
- Installation assumptions carried from a prior program are shown to hold on this airframe
Evidence normally required
- The certification basis and issue papers for the rotorcraft installation
- Crew-interface analysis and the operating context for the equipment
- DO-160G qualification reports, including any prior-airframe results being reused
- DO-178C life-cycle data for the equipment software
- Installation drawings and the assumptions the equipment relies on
Common discrepancies
- Environmental qualification reused from a fixed-wing program that never saw the rotorcraft vibration profile
- A crew-interface argument that assumes a workload the rotorcraft does not match
- Display-behavior substantiation missing for a degraded mode specific to the rotorcraft function
- An installation assumption from the original airframe that no longer holds on this one
What is at stake
Reused qualification that does not cover the rotorcraft vibration profile leaves the environmental finding open, and a crew-interface argument built for a different cockpit can fail to address the pilot workload Part 27 expects. Both push the equipment back into test or analysis at the point where the installation program has already committed to a schedule.
Move from findings to resolution
Identify gaps against the means of compliance.
How the work runs
Reset the basis
Identify the Part 27 paragraphs that now apply to the flight-deck function on the rotorcraft.
Sort the carryover
Separate evidence that transfers cleanly from evidence tied to the original airframe.
Test the assumptions
Confirm environmental, interface, and installation evidence holds in the rotorcraft context.
Sequence the work
Order the open findings so environmental and crew-interface items are cleared first.
What the buyer receives
- A Part 27 standards map linking each paragraph to its evidence and status
- A gap list identifying the qualification, interface, or installation evidence still owed
- A closure sequence that prioritizes the environmental and crew-interface findings
Who uses the output
- Certification leads answering Part 27 findings on the flight-deck equipment
- Engineering leads scoping the re-qualification or re-analysis the rotorcraft demands
- Compliance managers tracking which findings remain open before submittal
How the work fits into the transaction or program
The mapping runs when equipment moves onto a normal-category rotorcraft and the basis changes from whatever it was first certified against to Part 27. It separates the evidence that carries over cleanly from the evidence that assumed a different airframe, so the team knows what has to be redone before it reaches the finding response.
Start with a single asset
Confirm requirements trace through verification.
Jurisdiction-specific considerations
Part 27 under the FAA and CS-27 under EASA align on most flight-deck expectations, but crew-interface and workload substantiation can be argued differently, so the map notes where a package accepted by one authority may need restatement for the other.
Regulatory limits
The mapping shows how the equipment's evidence meets the Part 27 basis and where it falls short. It does not issue a compliance finding, approve the equipment or its rotorcraft installation, or make an airworthiness determination, all of which rest with the authority.
What this review does not cover
- Re-running environmental qualification against the rotorcraft profile
- Producing new crew-interface or workload analysis
- Issuing any compliance finding or approval on the equipment
Specific to this review
- Rotorcraft vibration environments routinely exceed the DO-160G categories a fixed-wing qualification was run to, so reused environmental evidence is the first thing to check on a Part 27 move.
- Crew workload on a normal-category rotorcraft differs enough from a fixed-wing cockpit that an interface argument can pass on one and fail on the other with no change to the hardware.
- Installation assumptions are the quiet failure point, because equipment reused across airframes carries forward positions and interfaces that the new rotorcraft may not provide.
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. FAA type certification process, certification basis establishment, and compliance findings.
SAE International. Development assurance process at aircraft and system level, including requirements capture and validation.
Frequently asked questions
The equipment is already certified on a fixed-wing type. Why redo anything for Part 27?
The prior certification was against that airframe's basis and environment. A normal-category rotorcraft imposes a different vibration profile and crew workload, so the environmental qualification and crew-interface evidence have to be checked against Part 27 rather than assumed to carry over.
Relevant glossary terms
Related pages
Where this fits
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