Parts of spark-ignition reciprocating or rotary internal combustion piston engines for aircraft

1. Scope and Applicability

This PCR applies to new, finished parts manufactured specifically for spark-ignition reciprocating or rotary internal combustion piston engines for aircraft. The declared product must be an individually identified part that is complete, conforms to its applicable approved design or controlling specification, and is eligible for installation without further manufacturing.

The cradle-to-gate foreground boundary begins with purchased material stock, castings, forgings, or supplier-finished subparts at the reporting organization's gate. It includes the manufacturing, special processing, inspection, nonconforming-part control, preservation, and release activities controlled by the producer. Supplier-controlled manufacturing and special processes remain inside the product system through upstream datasets. Aircraft-engine assembly, complete engines, compression-ignition engine parts, turbojet and turboprop parts, maintenance-fabricated or remanufactured parts, aircraft operation, maintenance, and end-of-life are excluded.

Because part numbers, alloys, geometries, and special-process routes differ materially, results are comparable only when all required qualifiers and the same gate boundary are declared. This PCR does not treat one kilogram of different part numbers as functionally interchangeable.

2. Product Category Identity

Field	Value
canonical_pcr_id	pcr.metal-products-machinery-and-equipment.general-purpose-machinery.parts-of-spark-ignition-reciprocating-or-rotary-internal-combustion-piston-engines-for-aircraft
classification_refs	CPC 3.0: 43152 (exact classification context)
covered_products	New, finished, serviceable cylinder, piston, connecting-rod, crankshaft, crankcase, valve-train, bearing-housing, and other individually identified parts made specifically for aircraft spark-ignition reciprocating or rotary piston engines, when supplied as parts rather than complete engines.
excluded_products	Complete engines; generic engine parts not restricted to aircraft spark-ignition piston engines; compression-ignition engine parts; turbojet, turboprop, and other reaction-engine parts; propellers; electrical ignition equipment classified separately; maintenance-fabricated, repaired, overhauled, or remanufactured parts; raw material and unfinished stock not eligible for installation.
representative_product	A released, individually identified aircraft spark-ignition piston-engine part conforming to the applicable drawing, material and process specification, inspection status, and production-approval basis.
production_route	Purchased material or near-net blank; machining and cleaning; route-specific heat treatment; route-specific surface preparation, anodizing, plating, or coating; inspection, nonconforming-part control, preservation, and release. Outsourced steps are represented by supplier datasets rather than omitted.
market_state	New, accepted, serviceable part at the manufacturer's gate, with part number, revision/configuration, material grade, process route, acceptance status, and net accepted mass declared; transport packaging excluded unless explicitly brought into the dataset boundary.

3. Reference Flow

Field	Value
What	Provision of a new, conforming, serviceable part made specifically for an aircraft spark-ignition reciprocating or rotary piston engine.
How much	1 kg net accepted mass of the declared part number and configuration at the manufacturer's gate.
How well	Conforms to the applicable approved design or controlling specification, including declared material, dimensions, special processes, inspection status, marking, and release basis.
How long or cycle	One production and release cycle ending at the manufacturer's gate; no equivalence in service life among different part numbers is asserted.
reference_flow_link	aircraft_engine_part_output

Field	Value
Reference amount	1 kg net accepted product
Reference product flow	Parts of spark-ignition reciprocating or rotary internal combustion piston engines for aircraft (UUID unresolved)
Reference flow property	Mass 93a60a56-a3c8-11da-a746-0800200b9a66
Reference unit group	Units of mass 93a60a57-a4c8-11da-a746-0800200c9a66
Reference unit	kg
Required qualifiers	part name and part number; drawing and revision/configuration; reciprocating or rotary engine application; aircraft application and eligibility basis; material grade and product state; purchased-stock or near-net-blank state; heat-treatment route; surface-treatment route; inspection and release status; net accepted mass; manufacturing site and geography; reporting period; outsourced-process boundary; allocation and recycling treatment; packaging inclusion status

When constructing a foreground data package, every item listed in Required qualifiers must be declared in dataset metadata, process notes, the reference-flow comment, the product description, or an equivalent data-package field. A missing qualifier makes the reference-flow definition incomplete.

4. Measurement and Unit Rules

rule_id	Applies to	Required property	Required unit	Rule
reference_mass	reference product	Mass 93a60a56-a3c8-11da-a746-0800200b9a66	kg	Use the net mass of accepted parts after final processing and before excluded transport packaging. Normalize all inventory quantities to 1 kg accepted product.
accepted_product_mass	production batches	Mass	kg	Determine accepted product mass from calibrated scales or part-count multiplied by a controlled, current measured mass per part number; exclude rejected parts and samples not released as product.
energy_conversion	electricity	Net calorific value 93a60a56-a3c8-11da-a746-0800200b9a66	MJ	Preserve metered electricity in its recorded unit and convert kWh to MJ using 1 kWh = 3.6 MJ. Do not mix electricity with fuel energy.
gas_volume_conditions	natural gas	Volume 93a60a56-a3c8-22da-a746-0800200c9a66	m3	Record metered gas volume and disclose the temperature, pressure, dry/wet basis, and any standard-volume conversion used.
aqueous_mass_conversion	process water and aqueous wastewater	Mass	kg	Prefer measured mass. When only volume is available, convert with a measured or documented density applicable to the stream and reporting conditions, and retain both the original volume and density evidence.

5. System Boundary

Boundary Abstraction

Field	Value
declared_starting_condition	Purchased alloy stock, casting, forging, or supplier-finished subpart received with material/product identity, mass, supplier, geography, production route, and upstream-dataset reference.
starting_condition_role	Cradle-to-gate starting condition for the reporting organization's controlled manufacturing route.
product_classification_scope	New, finished parts specifically for aircraft spark-ignition reciprocating or rotary piston engines; not complete engines or generic/non-aircraft engine parts.
recursive_input_rule	A purchased input that already meets this same finished-part category is recorded as one product input with its own upstream dataset, declared part number and gate, and is not recursively decomposed inside the receiving foreground process.
upstream_dataset_requirement	Every purchased material, near-net blank, supplier-finished part, and outsourced special process must carry a geographically and technologically representative upstream dataset or be disclosed as an unresolved data gap; supplier-controlled burdens may not be omitted.
disclosure	Declare material and product state at entry, exact controlled and outsourced operations, cut-offs, site and period, yield and reject accounting, energy and water meter allocation, treatment destinations, packaging status, and any excluded tooling or capital goods.

rule_id	Applies to	Rule	source_ids
sb_cradle_to_gate	all foreground datasets	Include purchased-input supply, all producer-controlled manufacturing and special processes, inspection, nonconforming-part handling, preservation, and release through the manufacturer's gate.	un-cpc-3-0-structure-2025; faa-ac-21-43a-2015; faa-ac-43-18-chg-2-2011
sb_outsourced_processes	outsourced machining, heat treatment, surface treatment, inspection, and other special processes	Represent the supplier service and its material, energy, emission, and waste burdens with an upstream dataset; do not treat outsourcing as a cut-off.	faa-ac-21-43a-2015; faa-ac-43-18-chg-2-2011
sb_use_and_end_of_life	downstream aircraft and engine stages	Exclude engine assembly, aircraft integration, operation, maintenance, replacement, and end-of-life unless a study explicitly extends the boundary and reports those stages separately.	un-cpc-3-0-structure-2025

6. Process Inventory Structure

Process Map

process_id	process_name	inclusion	inclusion_condition	role	quantitative_reference
machining_and_cleaning	Material preparation, machining, and cleaning	required	Always include the controlled operations that turn purchased stock or near-net blanks into the declared part geometry; represent purchased finished subparts as recursive inputs under the boundary rule.	Foreground manufacturing and material-removal accounting.	Inputs, chips, spent machining fluid, energy, and water per 1 kg accepted part.
heat_treatment	Heat treatment and quenching	conditional	Include when thermal treatment or oil quenching is performed under the declared route; use supplier datasets when outsourced.	Controlled thermal processing.	Fuel, electricity, quenching-oil make-up, direct fossil CO2, and spent quench oil per 1 kg accepted part.
surface_treatment	Surface preparation and chromium-bearing anodizing or plating	conditional	Include only when the declared part route uses the represented alkaline cleaning, acid activation, chromic-acid anodizing, or chromium plating steps; other finishes require separate atomic rows.	Controlled surface processing and rinse/wastewater accounting.	Electricity, water, bath-chemical make-up, and wastewater per 1 kg accepted part.
inspection_and_release	Inspection, nonconforming-part control, preservation, and release	required	Always include final conformity activities and the measured disposition of nonconforming parts; include route-specific NDI consumables as additional atomic rows in the foreground dataset.	Quality release and final reference-product output.	Inspection energy, reject mass, and 1 kg accepted product.

Process: Material preparation, machining, and cleaning (machining_and_cleaning)

Inputs

Product flows

Aluminium-alloy casting blank (aluminium_alloy_casting)

Record the measured mass of the exact aluminium-alloy casting grade entering machining when this material route applies.

• Selected flow: Aluminium-alloy casting, declared alloy grade and casting state (UUID unresolved)
• Flow property / unit: Mass / kg
• Amount rule: Measured received mass consumed by the declared production batch, net of returned unused stock
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_machining_records
• Sources: faa-ac-43-18-chg-2-2011

Alloy-steel forging blank (alloy_steel_forging)

Record the measured mass of the exact alloy-steel forging grade entering machining when this material route applies.

• Selected flow: Alloy-steel forging, declared alloy grade and forged state (UUID unresolved)
• Flow property / unit: Mass / kg
• Amount rule: Measured received mass consumed by the declared production batch, net of returned unused stock
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_machining_records
• Sources: faa-ac-43-18-chg-2-2011

Machining electricity (machining_electricity)

Record electrical energy delivered to machine tools, chip and fluid handling, and in-boundary cleaning equipment.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: Submetered electricity or documented equipment power multiplied by operating time and allocated under section 7
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_machining_records
• Sources:

Machining and cleaning process water (machining_process_water)

Record water supplied across the process boundary for machining-fluid preparation and part cleaning.

• Selected flow: Process Water 94a04f7e-2d5c-41f0-b182-d54a3b373a02
• Flow property / unit: Mass / kg
• Amount rule: Metered or batch-recorded process-water mass; exclude recirculated water until make-up crosses the boundary
• Value mode: Foreground record (foreground_record)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_machining_records
• Sources:

Cutting-fluid make-up (cutting_fluid)

Record purchased cutting fluid crossing the process boundary; declare formulation, concentration, and whether it is neat oil or water-miscible concentrate.

• Selected flow: Cutting Fluid 576d250f-4f36-4385-939d-0f03b8f95a10
• Flow property / unit: Mass / kg
• Amount rule: Measured make-up fluid added during the reporting period and assigned to the declared production batch
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_machining_records
• Sources:

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Aluminium machining chips (aluminium_machining_chips)

Record segregated aluminium-alloy chips and swarf leaving the process when the aluminium route applies.

• Selected flow: Aluminium-alloy machining chips, declared alloy and contamination state (UUID unresolved)
• Flow property / unit: Mass / kg
• Amount rule: Measured dispatched or inventory-adjusted chip mass
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_machining_records
• Sources:

Steel machining chips (steel_machining_chips)

Record segregated steel chips and swarf leaving the process when the alloy-steel route applies.

• Selected flow: Steel scrap, machining chips c978e4fc-350b-4fb6-8021-90eb5a6ed034
• Flow property / unit: Mass / kg
• Amount rule: Measured dispatched or inventory-adjusted chip mass
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_machining_records
• Sources:

Waste cutting oil (waste_cutting_oil)

Record spent neat cutting oil leaving the process only when the declared machining-fluid route uses neat oil.

• Selected flow: Waste cutting oil 80d926e3-0f76-4a19-9b1e-ffec9deb1216
• Flow property / unit: Mass / kg
• Amount rule: Measured mass sent to the declared recovery or treatment route
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_machining_records
• Sources:

Spent water-miscible cutting-fluid emulsion (spent_water_miscible_cutting_fluid_emulsion)

Record spent water-miscible machining emulsion separately from neat waste cutting oil when that route applies.

• Selected flow: Spent water-miscible cutting-fluid emulsion (UUID unresolved)
• Flow property / unit: Mass / kg
• Amount rule: Measured mass sent to the declared recovery or treatment route
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_machining_records
• Sources:

Elementary flows

Process: Heat treatment and quenching (heat_treatment)

Inputs

Product flows

Heat-treatment natural gas (heat_treatment_natural_gas)

Record gaseous natural gas burned in an in-boundary furnace only when the declared heat-treatment route uses it.

• Selected flow: natural gas in the gaseous state 4f19ca0e-7b3b-11dd-ad8b-0800200c9a66
• Flow property / unit: Volume / m3
• Amount rule: Metered standard or actual volume assigned to the declared heat-treatment batches
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_heat_treatment_records
• Sources:

Heat-treatment electricity (heat_treatment_electricity)

Record electricity supplied to electric furnaces, furnace auxiliaries, quench circulation, and controls when in boundary.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: Submetered electricity or documented equipment power multiplied by operating time and allocated under section 7
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_heat_treatment_records
• Sources:

Quenching-oil make-up (quenching_oil)

Record new quenching oil added to the bath when oil quenching is part of the declared route; do not record the circulating bath inventory as consumption.

• Selected flow: Quenching Oil 02f62137-e204-46e6-8e72-e88b450fbdc4
• Flow property / unit: Mass / kg
• Amount rule: Measured make-up and replacement oil charged during the reporting period and assigned to treated batches
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_heat_treatment_records
• Sources:

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Spent quenching oil (spent_quenching_oil)

Record spent quenching oil removed from the bath and transferred to the declared recovery or treatment route.

• Selected flow: spent quench oil 0f997fd8-26b1-432f-a8b8-e2703616b018
• Flow property / unit: Mass / kg
• Amount rule: Measured removed mass, adjusted for documented off-site return or on-site inventory change
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_heat_treatment_records
• Sources:

Elementary flows

Direct fossil carbon dioxide (fossil_carbon_dioxide)

Record only direct fossil CO2 from in-boundary fuel combustion; upstream electricity emissions remain in electricity datasets.

• Selected flow: carbon dioxide (fossil) 08a91e70-3ddc-11dd-923d-0050c2490048
• Flow property / unit: Mass / kg
• Amount rule: Site-measured direct emission assigned to the heat-treatment batches, or a disclosed calculation from metered fuel, fuel carbon content, and oxidation evidence
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_heat_treatment_records
• Sources:

Process: Surface preparation and chromium-bearing anodizing or plating (surface_treatment)

Inputs

Product flows

Surface-treatment electricity (surface_treatment_electricity)

Record electricity supplied to rectifiers, bath heating, ventilation, pumps, and in-boundary emission controls for the declared route.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: Submetered electricity assigned to the declared parts and treatment batches
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_surface_treatment_records
• Sources: us-epa-ap42-12-20-electroplating-2021

Surface-treatment process water (surface_treatment_process_water)

Record water added to treatment baths, cleaning, and rinsing; count only make-up crossing the boundary.

• Selected flow: Process Water 94a04f7e-2d5c-41f0-b182-d54a3b373a02
• Flow property / unit: Mass / kg
• Amount rule: Metered or batch-recorded water input assigned to the declared treatment batches
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_surface_treatment_records
• Sources: us-epa-ap42-12-20-electroplating-2021

Sodium-hydroxide make-up (sodium_hydroxide)

Record sodium hydroxide added for alkaline cleaning or etching only when used by the declared surface-treatment recipe.

• Selected flow: Sodium hydroxide e0abcced-0611-4c24-9290-5a2c5a0c4169
• Flow property / unit: Mass / kg
• Amount rule: Mass of active sodium hydroxide in purchased solution or solid make-up assigned to the declared batches; retain concentration evidence
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_surface_treatment_records
• Sources: us-epa-ap42-12-20-electroplating-2021

Sulfuric-acid make-up (sulfuric_acid)

Record sulfuric acid added for acid activation or bath chemistry only when used by the declared recipe.

• Selected flow: Sulfuric acid 7ee2e3c3-bee7-4520-92b7-3e23afbfcd6f
• Flow property / unit: Mass / kg
• Amount rule: Mass of active sulfuric acid in purchased solution assigned to the declared batches; retain concentration evidence
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_surface_treatment_records
• Sources: us-epa-ap42-12-20-electroplating-2021

Chromic-acid make-up (chromic_acid)

Record chromic acid added only for a declared chromic-acid anodizing or hexavalent-chromium plating route.

• Selected flow: Chromic acid solution, declared concentration and bath role (UUID unresolved)
• Flow property / unit: Mass / kg
• Amount rule: Mass of active chromic acid in purchased or prepared make-up assigned to the declared batches; retain composition and concentration evidence
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_surface_treatment_records
• Sources: us-epa-ap42-12-20-electroplating-2021

Waste flows

Elementary flows

Outputs

Product flows

Waste flows

Chromium-containing metal-finishing wastewater (chromium_containing_metal_finishing_wastewater)

Record the combined aqueous discharge transferred from the declared chromium-bearing treatment line to on-site or off-site treatment, before treatment when that is the process boundary.

• Selected flow: Chromium-containing metal-finishing wastewater, declared chromium speciation and concentration (UUID unresolved)
• Flow property / unit: Mass / kg
• Amount rule: Measured discharge mass, or measured volume converted with applicable density, assigned to the declared treatment batches
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_surface_treatment_records
• Sources: us-epa-ap42-12-20-electroplating-2021

Elementary flows

Process: Inspection, nonconforming-part control, preservation, and release (inspection_and_release)

Inputs

Product flows

Inspection electricity (inspection_electricity)

Record electricity supplied to dimensional inspection, nondestructive inspection, final cleaning, marking, and release-document equipment within the declared boundary.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value / MJ
• Amount rule: Submetered electricity or documented equipment power multiplied by operating time and assigned to accepted and rejected parts
• Value mode: Foreground record (foreground_record)
• Specificity: Technology-specific (technology_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_inspection_release_records
• Sources: faa-ac-21-43a-2015

Waste flows

Elementary flows

Outputs

Product flows

Accepted aircraft piston-engine part (aircraft_engine_part_output)

Record only parts that have passed the declared inspection and release process.

• Selected flow: Parts of spark-ignition reciprocating or rotary internal combustion piston engines for aircraft (UUID unresolved)
• Flow property / unit: Mass / kg
• Amount rule: 1 kg net accepted reference product by definition; retain measured batch accepted mass before normalization
• Value mode: Fixed value (fixed_value)
• Specificity: Generic (generic)
• Normalization basis: 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Method formula (method_formula)
• Sources: un-cpc-3-0-structure-2025; faa-ac-21-43a-2015

Waste flows

Nonconforming aircraft piston-engine part (nonconforming_aircraft_engine_part)

Record the mass of rejected parts rendered unusable or transferred to a documented non-product disposition; do not net it against recyclable-metal inputs.

• Selected flow: Nonconforming aircraft spark-ignition piston-engine part, segregated for controlled disposition (UUID unresolved)
• Flow property / unit: Mass / kg
• Amount rule: Measured rejected-part mass by part number and disposition during the reporting period
• Value mode: Foreground record (foreground_record)
• Specificity: Product-specific (product_specific)
• Normalization basis: per 1 kg accepted reference product
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Collected record (collected_record)
• Collection protocol: cp_inspection_release_records
• Sources: faa-ac-21-43a-2015

Elementary flows

7. Allocation and Co-product Handling

rule_id	Applies to	Rule	source_ids
allocation_subdivision	shared machines, furnaces, baths, ventilation, and inspection equipment	Prefer submetering, batch records, machine time, bath loading, or another measured causal driver. Document the driver and reconcile allocated totals to facility records.
allocation_recycling	aluminium chips, steel chips, rejected parts, waste oils, and other recovered residues	Report gross waste output and its destination. Do not subtract recycling credit or avoided virgin production from the foreground inventory; any recycling benefit must be modelled and disclosed in a separate downstream scenario.
allocation_multi_output	production campaigns with more than one saleable part	Subdivide by part number when feasible. If subdivision is not feasible, use a documented physical causal relation; economic allocation requires explicit justification and sensitivity disclosure.

8. Foreground Data Collection, Calculation, and Quality Rules

Data Collection Protocols

protocol_id	process_id	flow_role	record_type	raw_fields	collection_method	unit	frequency	temporal_coverage	site_scope	aggregation_rule	quality_evidence
cp_machining_records	machining_and_cleaning	Material, electricity, water, cutting fluid, chips, and spent machining fluid	Purchase/issue records, scales, meters, batch travellers, and waste manifests	part_number; batch_id; accepted_mass_kg; input_identity; input_mass_kg; electricity_MJ_or_kWh; water_mass_or_volume; cutting_fluid_mass_kg; chip_material; chip_mass_kg; spent_fluid_identity; spent_fluid_mass_kg; inventory_change; destination	Reconcile direct meters and weighed issues/dispatches to each production batch; retain original units and allocation keys.	kg; MJ; kWh; m3	Per batch with at least monthly reconciliation	Representative continuous 12-month period or complete shorter campaign disclosed	All controlled machining and cleaning operations at the reporting site and included suppliers	Sum net boundary-crossing quantities by atomic flow, allocate only shared quantities under section 7, and divide by accepted part mass.	Calibration records, purchase and issue records, batch travellers, meter totals, waste manifests, and material-balance reconciliation
cp_heat_treatment_records	heat_treatment	Fuel, electricity, quenching oil, direct fossil CO2, and spent quench oil	Furnace meters, cycle logs, bath make-up/removal logs, emission records, and batch travellers	batch_id; furnace_id; cycle; treated_part_mass_kg; accepted_mass_kg; gas_m3; gas_conditions; electricity_MJ_or_kWh; quench_oil_added_kg; quench_oil_removed_kg; direct_fossil_co2_kg; emission_calculation_inputs	Link each furnace cycle and bath transaction to treated batches; retain measured fuel and electricity and all emission-calculation inputs.	kg; MJ; kWh; m3	Per furnace cycle and bath transaction, reconciled monthly	Representative continuous 12-month period or complete shorter campaign disclosed	All in-boundary heat-treatment and quench equipment and included supplier services	Allocate shared cycles by measured treated mass or another documented causal driver, then divide by accepted part mass.	Calibrated meter records, furnace charts, controlled recipes, bath logs, emission records, and batch traceability
cp_surface_treatment_records	surface_treatment	Electricity, water, sodium hydroxide, sulfuric acid, chromic acid, and wastewater	Rectifier and utility meters, bath analyses, chemical issue records, rinse records, discharge meters, and treatment manifests	batch_id; route; treated_area_or_mass; accepted_mass_kg; electricity_MJ_or_kWh; water_mass_or_volume; chemical_identity; solution_mass_kg; concentration; active_chemical_mass_kg; wastewater_mass_or_volume; density; chromium_speciation; destination	Record each chemical separately on an active-substance basis, retain solution concentration, and reconcile bath additions, drag-out, rinse discharge, and inventory changes.	kg; MJ; kWh; m3	Per batch and chemical addition, reconciled monthly	Representative continuous 12-month period or complete shorter campaign disclosed	All in-boundary surface-treatment, rinse, ventilation, and wastewater-transfer operations	Sum atomic inputs and outputs by declared route, allocate shared baths by measured ampere-hours, treated area, or another documented causal driver, and divide by accepted part mass.	Calibrated meters, certificates of analysis, bath-control logs, purchase/issue records, discharge records, and hazardous-waste documentation
cp_inspection_release_records	inspection_and_release	Inspection electricity, accepted product, and nonconforming parts	Inspection/test records, equipment logs, calibrated scales, release records, and nonconformance dispositions	part_number; revision; batch_id; inspection_route; electricity_MJ_or_kWh; accepted_count; accepted_mass_kg; rejected_count; rejected_mass_kg; disposition; release_status	Link energy, accepted mass, and reject mass to the same part-number campaign and retain authorized inspection and disposition records.	kg; MJ; kWh; Item(s)	Per batch or release lot, reconciled monthly	Representative continuous 12-month period or complete shorter campaign disclosed	All final inspection, marking, preservation, release, and nonconforming-part control in boundary	Sum accepted and rejected mass by part number, allocate shared inspection energy causally, and normalize to accepted mass only.	Inspection and test records, calibration status, release documents, nonconformance authorization, segregation evidence, and final disposition records

Calculation Rules

rule_id	Applies to	Formula or rule	Inputs	Output	source_ids
calc_reference_normalization	every inventory row	normalized quantity = net boundary-crossing quantity assigned to the declared part number / net accepted part mass for the same reporting period	atomic flow quantity; allocation key where needed; accepted_mass_kg	quantity per 1 kg accepted reference product
calc_electricity_conversion	electricity records	electricity_MJ = electricity_kWh × 3.6; preserve the original meter reading and unit	electricity_kWh	electricity_MJ
calc_solution_active_mass	sodium hydroxide, sulfuric acid, and chromic acid	active chemical mass = solution mass × measured or certificate concentration mass fraction	solution_mass_kg; concentration_mass_fraction	active_chemical_mass_kg	us-epa-ap42-12-20-electroplating-2021
calc_direct_fossil_co2	direct furnace CO2 when not continuously measured	Use the site's documented fuel-carbon calculation with metered fuel, fuel carbon content, oxidation evidence, and unit conversions; disclose the equation and factors rather than applying an undeclared default.	gas_m3 or fuel mass; reference conditions; carbon content; oxidation factor; molecular conversion	fossil_carbon_dioxide_kg
calc_aqueous_mass	water or wastewater recorded by volume	mass = measured volume × stream density at the declared conditions	volume; density; temperature and concentration conditions	water_or_wastewater_mass_kg

Data Quality Requirements

requirement_id	Applies to	Requirement	Evidence
dq_identity_traceability	reference product and all material inputs	Preserve part number, current drawing/revision, material grade, supplier or site, batch/lot, process route, inspection status, and raw-material-to-completed-part traceability.	Controlled design data, batch travellers, certificates, supplier records, inspection status, and release record
dq_temporal_scope	all foreground records	Use one representative continuous 12-month period where available; a shorter complete campaign must state dates, production volume, seasonality limits, and why it is representative.	Meter coverage, production calendar, batch list, and reconciliation
dq_atomic_completeness	all process inventories	Reconcile purchased inputs, utilities, chemicals, wastes, direct emissions, accepted mass, rejected mass, and inventory changes; add every additional route-specific exchange as a separate atomic row.	Material and energy balances, bills, meters, bath logs, waste manifests, and omission register
dq_special_processes	heat treatment, anodizing, plating, coating, and nondestructive inspection	Declare whether each process is in-house or outsourced and retain controlled route, supplier, recipe/specification, acceptance evidence, and upstream dataset link.	Special-process certification, supplier control record, work instruction, inspection/test record, and upstream dataset
dq_measurement	meters, scales, gauges, and test equipment	Use calibrated equipment over the reporting period; document estimation, downtime, missing-data substitution, and uncertainty.	Calibration status, meter logs, maintenance records, and missing-data register
dq_unresolved_uuid	inventory rows without a confirmed Tiangong UUID	Preserve the exact atomic name and qualifiers and flag the identity as unresolved; never substitute a broader, differently classified, or differently stated flow.	UUID audit record and dataset-level unresolved-identity disclosure

9. Validation Rules

rule_id	Applies to	Rule	source_ids
val_product_identity	reference product	Fail validation if part number, revision/configuration, aircraft spark-ignition piston-engine application, material grade, approved-design or controlling-specification basis, acceptance status, or net accepted mass is missing.	un-cpc-3-0-structure-2025; faa-ac-21-43a-2015; faa-ac-43-18-chg-2-2011
val_boundary	foreground and supplier-controlled operations	Fail validation if an applicable machining, heat-treatment, surface-treatment, inspection, or supplier-controlled special process is omitted without an explicit exclusion and data-gap disclosure.	faa-ac-21-43a-2015; faa-ac-43-18-chg-2-2011
val_inventory_atomicity	all exchanges	Fail validation if an inventory row combines materials, utilities, fuels, chemicals, wastes, wastewater types, or emissions, or if route applicability is not declared.
val_mass_and_energy_reconciliation	production period	Require accepted mass, rejected mass, material inputs, recovered chips, waste oils, chemical/water outputs, electricity, and fuel totals to reconcile with source records and documented allocation keys.
val_quality_release	accepted and nonconforming parts	Fail validation if inspection/test status, authorized release basis, nonconforming-part segregation, or final disposition evidence is absent.	faa-ac-21-43a-2015
val_uuid_and_units	UUID-bearing and unresolved rows	Require UUID-bearing rows to retain the audited flow property and unit group; require unresolved rows to remain explicitly unresolved with the same row id and semantic qualifiers.

10. Published Dataset Profile

Field	Value
dataset_role	Product-specific cradle-to-gate secondary dataset generated from foreground manufacturing records.
downstream_use	May serve as a secondary_dataset or background_dataset for the declared part number in aircraft piston-engine, maintenance, or aircraft product systems when geography, technology, period, route, and product-state compatibility are demonstrated.
allowed_use	Product-footprint and LCA modelling for the same part number/configuration or a demonstrably equivalent material, manufacturing route, acceptance state, geography, and reporting period.
excluded_use	Comparison of different part numbers by mass alone; complete-engine representation; compression-ignition, turbine-engine, remanufactured, repaired, or maintenance-fabricated parts; use-phase or service-life claims without additional modelling.
required_metadata	canonical PCR id and version; part name/number and drawing revision; engine and aircraft application; material grade; purchased-input state; controlled and outsourced route; accepted and rejected mass; site/geography; reporting period; electricity mix and gas reference conditions; allocation; recycling and treatment destinations; packaging status; source and UUID gaps.
required_quality_disclosure	Primary-data share and coverage; meter and scale calibration; supplier-data coverage; missing-data treatment; mass/energy reconciliation; special-process traceability; inspection/release evidence; uncertainty; unresolved UUIDs and range-evidence needs.
update_trigger	New part or revision, material or supplier change, manufacturing or special-process change, site/geography change, electricity or fuel-supply change, allocation change, material yield or reject-rate shift, reporting period older than the user's representativeness requirement, or resolution of a UUID/source gap.

11. Data Sources

Source id	Type	Reference	Used for
un-cpc-3-0-structure-2025	Official guidance (official_guidance)	United Nations Statistics Division, CPC Version 3.0 Structure, 30 June 2025. https://unstats.un.org/unsd/classifications/Econ/Download/In%20Text/CPC_Ver_3.0_Structure_30Jun2025.csv (retrieved 2026-09-05).	English category identity and exclusions from adjacent CPC product classes.
un-cpc-1-1-chinese-2004	Official guidance (official_guidance)	United Nations Statistics Division, Central Product Classification Version 1.1, Chinese edition, ST/ESA/STAT/SER.M/77/Ver.1.1. https://digitallibrary.un.org/record/536544/files/M_77ver1_1c.pdf (retrieved 2026-09-05).	Official Chinese CPC 43152 terminology used to verify the professional current translation.
faa-ac-21-43a-2015	Official guidance (official_guidance)	Federal Aviation Administration, AC 21-43A, Production Under 14 CFR Part 21, Subparts F, G, K, and O, 1 October 2015. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_21-43A.pdf (retrieved 2026-09-05).	Manufacturing-process control, raw-material-to-completed-article traceability, inspection and testing, calibrated equipment, nonconforming-article control, supplier control, handling, storage, and quality records.
faa-ac-43-18-chg-2-2011	Official guidance (official_guidance)	Federal Aviation Administration, AC 43-18 with Changes 1 and 2, Fabrication of Aircraft Parts by Maintenance Personnel, 7 June 2011. https://www.faa.gov/documentLibrary/media/Advisory_Circular/Ac_43-18_Chg_1-2.pdf (retrieved 2026-09-05).	Installable-part boundary; design-data needs for materials, dimensions, processes, inspection and testing; and recognition of machining, plating, and welding as fabrication services.
us-epa-ap42-12-20-electroplating-2021	Official guidance (official_guidance)	United States Environmental Protection Agency, AP-42 Chapter 12, Section 20, Electroplating, October 2021. https://www.epa.gov/sites/production/files/2020-11/documents/c12s20.pdf (retrieved 2026-09-05).	Conditional aircraft-part chromium-plating and chromic-acid-anodizing process decomposition, including pretreatment, alkaline cleaning, acid dipping, rinsing, electricity, water, bath chemicals, and chromium-bearing emissions/wastes.