Part 29 rotorcraft
Part 29 certification basis mapping for sensor systems
This support measures a sensor system's evidence against the Part 29 certification basis for a transport-category rotorcraft. It serves suppliers and modifiers fitting air data, attitude, or other sensing equipment who need to know where the basis is answered and where it is open. The work follows the requirements trace, the calibration evidence, the environmental qualification, and the installation effects against the applicable paragraphs and their means of compliance. You receive a standards map that binds each rule to its evidence, a gap list ranked for closure, and an order for resolving the open items ahead of submittal or a finding reply.
When this review is needed
- An air data or attitude sensor is being installed on a transport-category rotorcraft and its evidence has not been mapped to the Part 29 basis.
- Calibration data has to be tied to the accuracy the applicable rule requires across the operating envelope.
- Installation effects such as position error or downwash need to be shown against the rules governing sensor accuracy.
- A finding request questions sensor performance or its requirements trace and needs a paragraph-level response.
The problem
Sensor evidence tends to arrive as a calibration certificate, a set of requirements, and an environmental report, without a connected trace from top-level requirement to sensor output to the Part 29 rule it answers. On a rotorcraft the installation effects are harder than on a fixed-wing, because rotor downwash and airframe flow distort what an air data sensor reads. A package that shows accuracy on the bench but never proves it in the installed position leaves the hardest question unanswered.
What gets reviewed
- Applicable Part 29 paragraphs for the sensing function fixed as the certification basis
- Requirements trace from top-level function through sensor requirements per ARP4754B
- Calibration evidence matched to the accuracy the rules require across the operating envelope
- Installation effects including position error, downwash, and airframe flow reconciled with installed accuracy
- DO-160G environmental qualification for the sensor's mounting and operating conditions
- Sensor failure modes and their effects reconciled with the criticality of the function served
What gets validated
- Each sensor requirement traces upward to a top-level function and downward to a verification per ARP4754B
- Calibration accuracy is demonstrated across the temperature and pressure range the envelope demands
- Installation position error is characterized for the sensor's location on this airframe, not assumed negligible
- DO-160G categories cover the vibration and environmental conditions of the sensor's mounting zone
- Sensor failure effects match the criticality assigned to the function in the safety assessment
Evidence normally required
- The proposed Part 29 certification basis for the sensor installation
- The requirements trace and the ARP4754B development artifacts for the sensing function
- Calibration certificates and accuracy data across the operating envelope
- Installation analysis covering position error and airframe flow effects
- DO-160G environmental qualification reports for the sensor units
Common discrepancies
- A sensor requirement with no verification closing the trace at the bottom
- Calibration accuracy proven on the bench but never corrected for the installed position error
- Position error assumed negligible on a rotorcraft where downwash makes it significant
- A DO-160G vibration category below what the sensor's mounting zone actually experiences
What is at stake
A sensor package with a broken requirements trace or unproven installation accuracy draws findings that can require flight testing to close, which is among the most expensive ways to resolve a gap. If a position error correction is missing, the sensor may read within tolerance on the bench yet fall outside it installed, and that only shows up once the aircraft is flying.
Move from findings to resolution
Identify gaps against the means of compliance.
How the work runs
Fix the sensor basis
Establish the Part 29 paragraphs governing the sensing function against the issue paper.
Walk the requirements trace
Follow each sensor requirement up to a top-level function and down to a verification per ARP4754B.
Prove installed accuracy
Check calibration and position error for the sensor's actual location on this rotorcraft.
Separate ground from flight gaps
Flag which open items close on the ground and which need flight data, then order them.
What the buyer receives
- A standards map binding each sensor rule to its trace, calibration, and installation evidence
- A gap list naming broken traces and unproven installation accuracy
- A closure order that flags which gaps can be closed on the ground and which need flight data
Who uses the output
- Certification engineers building the sensor submittal for the authority
- Suppliers deciding what calibration or installation analysis still has to be run
- Program leads planning closure around ground and flight test availability
How the work fits into the transaction or program
The support sits between the sensor's development data and the Part 29 submittal, turning a calibration certificate and a requirements set into a mapped and traced compliance position. Because installation accuracy on a rotorcraft often turns on flight data, the closure order separates those gaps early so flight test can be planned rather than discovered late.
Start with a single asset
Confirm requirements trace through verification.
Jurisdiction-specific considerations
FAA and EASA can require different substantiation for sensor accuracy and installation effects, and the accepted position error correction methods are not always identical. The mapping notes where a sensor finding under one authority needs its own installation or calibration evidence for the other.
Regulatory limits
The mapping shows where sensor evidence supports the Part 29 basis and where it is incomplete. It does not grant a compliance finding, approve the sensor installation, or certify accuracy on the authority's behalf. Those decisions rest with the authority and its designees.
What this review does not cover
- Performing the sensor calibration, environmental, or flight testing
- Developing the sensor requirements or the installation correction data
- Issuing any Part 29 finding or installation approval
Specific to this review
- Rotor downwash and airframe flow distort what an air data sensor reads on a rotorcraft, so installation position error is a first-order question rather than a rounding correction.
- A sensor that meets accuracy on the bench can fall outside tolerance once installed, and that gap only appears in flight, which is why installation accuracy is separated from bench calibration in the map.
- ARP4754B trace tends to break at the bottom, where a requirement has no closing verification, more often than at the top, so the trace is walked in both directions.
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
Why does installation position error matter more on a rotorcraft?
Rotor downwash and the airframe flow field distort the air an external sensor samples, so a sensor that reads accurately on the bench can be off once installed. The mapping treats installed accuracy as a separate item from bench calibration, because closing it often takes flight 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.
Talk through the aircraft, records, evidence, deadline, and next useful step.