This glossary explains specialized terminology used across the Aerospace & Defense sector to design, certify, industrialize, sell, and support commercial aircraft. It provides a practical reference for engineering, production, regulatory, supply-chain, customer, and performance discussions within the Commercial Aerospace OEMs Practice.
0–9 A B C D E F G H I J L M N O P Q R S T U V W Z
| 0–9 | |
| 14 CFR | Title 14 of the Code of Federal Regulations: The principal body of United States federal aviation regulations, including the rules governing aircraft certification, production approvals, operating requirements, and continued airworthiness. |
| A | |
| AC | Advisory Circular: Guidance published by the United States aviation regulator to describe acceptable methods of showing compliance with regulations. Although generally not mandatory, these publications strongly influence certification planning and evidence. |
| ACR | Aircraft Classification Rating: An International Civil Aviation Organization rating expressing an aircraft’s relative effect on pavement for a specified subgrade category. Manufacturers use it with the corresponding pavement rating to assess airport compatibility. |
| AD | Airworthiness Directive: A legally enforceable rule requiring action to correct an unsafe condition in an aircraft, engine, propeller, or appliance. Approval holders must develop corrective instructions and support affected operators. |
| AFM | Aircraft Flight Manual: The approved document containing operating limitations, procedures, and performance information required for safe operation of a particular aircraft type or individual aircraft. |
| AIA | Aerospace Industries Association: A United States trade association representing major aerospace and defense manufacturers and suppliers on regulatory, technical, workforce, trade, and industrial-base matters. |
| AMOC | Alternative Method of Compliance: A regulator-approved means of satisfying the requirements of an airworthiness mandate through an approach different from the one stated in the rule. |
| ANAC | National Civil Aviation Agency of Brazil: Brazil’s civil aviation regulator and a major validating authority for commercial aircraft intended for the Brazilian market. |
| APQP | Advanced Product Quality Planning: A structured method for translating customer and design requirements into controlled product and production plans. Aerospace manufacturers use it to manage supplier readiness, risk, validation, and launch quality. |
| APU | Auxiliary Power Unit: A small onboard power unit that typically supplies electrical power and compressed air when the main engines are not providing them. Its integration affects dispatch reliability, ground operations, noise, emissions, and aircraft architecture. |
| ARP4754A | Guidelines for Development of Civil Aircraft and Systems: An aerospace recommended practice providing a framework for aircraft and system requirements, validation, verification, development assurance, and integration. |
| ARP4761A | Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment: An aerospace recommended practice describing methods for identifying hazards, classifying failure conditions, and demonstrating that aircraft and systems meet safety objectives. |
| AS9100 | Quality Management Systems—Requirements for Aviation, Space, and Defense Organizations: The primary aerospace quality-management standard, adding sector-specific requirements for product safety, configuration control, risk, counterfeit-part prevention, and supplier oversight. |
| AS9102 | Aerospace First Article Inspection Requirement: The standard defining how organizations verify and document that a representative production article conforms to engineering and process requirements. |
| AS9145 | Requirements for Advanced Product Quality Planning and Production Part Approval Process: An aerospace standard for structured product-quality planning and evidence that production processes can repeatedly deliver conforming parts. |
| ASK | Available Seat Kilometer: An airline capacity measure calculated by multiplying available seats by kilometers flown. Manufacturers use customer capacity trends when forecasting fleet demand and evaluating aircraft market segments. |
| ATA | Air Transport Association of America: The source of the widely adopted specification system that organizes aircraft systems and technical information into standardized chapter numbers, supporting consistent documentation across manufacturers, suppliers, and operators. |
| B | |
| BASA | Bilateral Aviation Safety Agreement: An agreement between governments that enables cooperation and reciprocal acceptance in areas such as airworthiness certification, production oversight, and maintenance approvals. |
| BFE | Buyer-Furnished Equipment: Equipment selected and procured by the aircraft customer for installation by the manufacturer. Clear interface, delivery, certification, and warranty responsibilities are essential to protect final-assembly schedules. |
| BFL | Balanced Field Length: The takeoff runway length at which accelerate-stop and accelerate-go distances are equal under specified conditions. It is an important measure of airport performance for multi-engine aircraft. |
| BOM | Bill of Materials: The controlled hierarchy of parts, materials, assemblies, and quantities required to build a product. Accurate structures are fundamental to configuration control, procurement, costing, and production planning. |
| C | |
| CAA | Civil Aviation Authority: A common designation for a national regulator responsible for civil aviation safety and oversight. Manufacturers engage such authorities for certification, validation, production, and continued-airworthiness matters. |
| CAAC | Civil Aviation Administration of China: China’s national civil aviation regulator and a major authority for validating commercial aircraft and approving their operation in the Chinese market. |
| CAD | Computer-Aided Design: The use of digital tools to create, analyze, and control product geometry and engineering drawings. It underpins aircraft definition, configuration management, tooling, and supplier data exchange. |
| CAE | Computer-Aided Engineering: The use of simulation and analytical software to evaluate structures, aerodynamics, systems, thermal behavior, and other aspects of aircraft performance before physical testing. |
| CAEP | Committee on Aviation Environmental Protection: The technical committee that develops recommendations for international aircraft noise and emissions standards, shaping future product requirements and environmental certification. |
| CAM | Computer-Aided Manufacturing: The use of software and digital product data to plan, program, and control manufacturing equipment and processes. |
| CAPA | Corrective and Preventive Action: A quality process for eliminating the causes of detected nonconformities and preventing recurrence or occurrence of similar issues across products and processes. |
| CASA | Civil Aviation Safety Authority: Australia’s national civil aviation regulator and an important validating authority for commercial aircraft entering the Australian market. |
| CASK | Cost per Available Seat Kilometer: An airline unit-cost measure calculated by dividing operating costs by available seat kilometers. It is frequently used to compare the economic value of competing aircraft and cabin configurations. |
| CASM | Cost per Available Seat Mile: An airline unit-cost measure calculated by dividing operating costs by available seat miles. Manufacturers use it in product positioning and customer economic analyses, particularly in markets using statute miles. |
| CCA | Common Cause Analysis: A safety-assessment discipline used to identify failures that could defeat assumed independence among systems or components through shared resources, location, environment, or development errors. |
| CCAR | Civil Aviation Regulations of China: The Chinese regulatory framework governing aircraft airworthiness, certification, production, operation, and related civil aviation activities. |
| CDL | Configuration Deviation List: An approved list identifying external parts that may be missing for dispatch, together with operating limitations, performance penalties, and required procedures. |
| CDR | Critical Design Review: A formal program review confirming that a detailed design is sufficiently mature to proceed toward fabrication, integration, and verification. |
| CG | Center of Gravity: The point through which an aircraft’s total weight is considered to act. Its allowable range is fundamental to stability, control, loading, performance, and certification. |
| CMA | Common Mode Analysis: A safety analysis that evaluates whether supposedly independent items could fail in the same manner because of shared design features, processes, requirements, or errors. |
| CoC | Certificate of Conformity: Supplier or manufacturer documentation attesting that delivered items satisfy specified contractual, engineering, and quality requirements. |
| CofA | Certificate of Airworthiness: A national authority’s certificate confirming that an individual aircraft conforms to its approved type design and is in a condition for safe operation. |
| CONQ | Cost of Non-Quality: The cost generated by defects and process failures, including scrap, rework, concessions, disruption, inspections, warranty exposure, and corrective action. |
| CORSIA | Carbon Offsetting and Reduction Scheme for International Aviation: A global framework addressing growth in carbon emissions from international flights. It influences airline fuel strategies, sustainability requirements, and manufacturer product planning. |
| CP | Certification Plan: A project document defining the certification basis, applicable requirements, proposed means of compliance, evidence, responsibilities, and schedule for regulatory approval. |
| CRI | Certification Review Item: A formal record used by the European aviation regulator to document and resolve significant certification-basis, interpretation, compliance, or administrative issues. |
| CS | Certification Specifications: Detailed airworthiness standards and acceptable means used by the European aviation regulator when certifying aircraft, engines, propellers, and related products. |
| CS-25 | Certification Specifications for Large Aeroplanes: The European airworthiness specifications applied to the type certification of large turbine-powered commercial aeroplanes. |
| CTQ | Critical to Quality: A measurable product or process characteristic that must remain within defined limits to satisfy safety, regulatory, performance, or customer requirements. |
| CVE | Compliance Verification Engineer: An authorized specialist within a European-approved design organization who independently verifies compliance evidence in an assigned technical discipline. |
| D | |
| DAH | Design Approval Holder: The organization holding regulatory approval for an aircraft or product design and carrying obligations for design integrity, continued airworthiness, and corrective action. |
| DAL | Development Assurance Level: A rigor level assigned according to the severity of the failure condition a development error could cause. It drives the required independence, verification, control, and evidence for system development. |
| DDG | Dispatch Deviation Guide: Manufacturer guidance describing operational and maintenance procedures associated with dispatching an aircraft when specified equipment is inoperative or approved parts are missing. |
| DER | Designated Engineering Representative: An individual authorized by the United States aviation regulator to approve or recommend approval of specified technical data and findings of compliance. |
| DFM | Design for Manufacturing: The practice of shaping a product design so it can be built consistently, economically, safely, and at the required production rate. |
| DFMEA | Design Failure Mode and Effects Analysis: A structured assessment of potential design failures, their causes and effects, and the controls or design actions needed to reduce risk. |
| DMU | Digital Mock-Up: An integrated three-dimensional representation used to evaluate aircraft geometry, interfaces, clearances, accessibility, assembly sequences, and configuration before physical build. |
| DOA | Design Organisation Approval: European regulatory approval confirming that an organization has the structure, processes, resources, and independent checking needed to design and certify aeronautical products. |
| DOC | Direct Operating Cost: The operating expenses directly attributable to aircraft use, commonly including fuel, crew, maintenance, navigation, and ownership-related components. Assumptions must be stated because industry methodologies vary. |
| DPU | Defects per Unit: A quality metric showing the average number of defects found on each inspected unit, regardless of how many units contain defects. |
| E | |
| EASA | European Union Aviation Safety Agency: The European Union body responsible for common civil aviation safety rules and for certification and oversight functions covering aircraft and related products. |
| EBOM | Engineering Bill of Materials: The product structure organized according to the approved engineering design. It is the authoritative source from which manufacturing and service-oriented structures are derived. |
| ECS | Environmental Control System: The aircraft system that manages cabin pressurization, ventilation, temperature, and air distribution. Its design affects passenger comfort, energy use, safety, and aircraft integration. |
| EDTO | Extended Diversion Time Operations: The international operational framework for flights that remain beyond a specified diversion time from an adequate aerodrome. Aircraft capability and system reliability determine the approvals that operators can obtain. |
| EIS | Entry into Service: The point at which a new aircraft type, variant, or customer aircraft begins commercial operation. Readiness spans certification, delivery, training, documentation, spares, and technical support. |
| EMC | Electromagnetic Compatibility: The ability of electrical and electronic equipment to operate correctly in its electromagnetic environment without causing unacceptable interference to other equipment. |
| EO | Engineering Order: A controlled instruction authorizing defined engineering work, configuration changes, inspections, or incorporation of approved design data into production or delivered aircraft. |
| EPNdB | Effective Perceived Noise in Decibels: The unit used to express certificated aircraft noise after accounting for perceived noisiness, tonal content, and event duration. |
| ETOPS | Extended-range Twin-engine Operational Performance Standards: Requirements governing aircraft and operator capability for routes with long diversion times from suitable airports. Design reliability and propulsion-system performance are central to obtaining higher diversion-time approvals. |
| EWIS | Electrical Wiring Interconnection System: The aircraft wiring, connectors, terminations, protection devices, and related installation hardware treated as an integrated system for design, certification, production, and continued airworthiness. |
| F | |
| FAA | Federal Aviation Administration: The United States agency responsible for civil aviation safety regulation, aircraft certification, production oversight, air traffic functions, and operational standards. |
| FAI | First Article Inspection: A documented verification that the first representative item produced using planned processes conforms to all applicable engineering and specification requirements. |
| FAL | Final Assembly Line: The production stage where major aircraft sections, systems, interiors, engines, and customer-specific equipment are integrated, tested, and prepared for delivery. |
| FAR | Federal Aviation Regulations: The traditional industry name for United States civil aviation rules, now codified within the federal regulatory title governing aeronautics and space. |
| FCOM | Flight Crew Operating Manual: A manufacturer-issued manual describing aircraft systems, normal and abnormal procedures, limitations, and performance information for flight crews. |
| FCTM | Flight Crew Training Manual: Manufacturer guidance explaining recommended piloting techniques, operational considerations, and training practices for an aircraft type. |
| FDAL | Functional Development Assurance Level: The assurance classification assigned to an aircraft or system function based on the severity of potential failure conditions and the protection provided by the architecture. |
| FHA | Functional Hazard Assessment: An early safety analysis that identifies aircraft or system functions, evaluates potential failure conditions, and assigns severity classifications and safety objectives. |
| FMEA | Failure Mode and Effects Analysis: A systematic bottom-up analysis of how individual item failures affect higher-level functions, systems, products, or processes. |
| FOD | Foreign Object Damage: Physical harm to an aircraft, engine, component, or tool caused by an object that should not be present in the operating or production environment. |
| FOD | Foreign Object Debris: Loose material or articles that could contaminate assemblies, injure personnel, or damage aircraft and equipment. Prevention and detection are core production and flight-line controls. |
| FPY | First Pass Yield: The percentage of units completing a process correctly on the first attempt without rework, repair, retest, or rerouting. |
| FRACAS | Failure Reporting, Analysis, and Corrective Action System: A closed-loop reliability process for recording failures, determining causes, implementing corrective actions, and confirming their effectiveness. |
| FSC | Full-Service Carrier: An airline business model generally offering multiple cabin classes, connecting networks, and bundled passenger services. Its requirements can materially affect aircraft range, cabin, cargo, and customization choices. |
| FTA | Fault Tree Analysis: A top-down deductive safety method that models combinations of failures and events capable of producing a defined undesirable outcome. |
| G | |
| GSE | Ground Support Equipment: Equipment used to service, move, test, power, load, or maintain aircraft while on the ground. Manufacturers define compatibility and provisioning requirements for customer operations. |
| H | |
| HIRF | High-Intensity Radiated Fields: Strong external electromagnetic environments against which safety-critical aircraft electrical and electronic systems must be protected and certificated. |
| I | |
| IAQG | International Aerospace Quality Group: The global aerospace organization that develops sector quality standards, harmonizes certification practices, and maintains supporting supplier-certification infrastructure. |
| IATA | International Air Transport Association: The global airline trade association that develops operational and commercial standards and provides traffic, safety, economic, and sustainability data relevant to aircraft manufacturers. |
| ICA | Instructions for Continued Airworthiness: Regulatory deliverables specifying the maintenance, inspection, access, control, and life-limit information needed to keep a product airworthy throughout service. |
| ICAO | International Civil Aviation Organization: The United Nations specialized agency that establishes global standards and recommended practices for international civil aviation, including safety, operations, noise, and emissions. |
| ICCAIA | International Coordinating Council of Aerospace Industries Associations: The body through which aerospace manufacturing associations coordinate technical industry input to international civil aviation policy and standards. |
| ICD | Interface Control Document: A controlled definition of the physical, functional, electrical, data, environmental, and organizational interfaces between aircraft elements or responsible parties. |
| IDAL | Item Development Assurance Level: The assurance rigor allocated to a hardware or software item after considering the system architecture and the item’s contribution to functional failure conditions. |
| IFSD | In-Flight Shutdown: The shutdown of an engine during flight, whether commanded or caused by a malfunction. Rates are closely monitored because they affect propulsion reliability and extended-diversion capability. |
| IPT | Integrated Product Team: A cross-functional team combining engineering, manufacturing, quality, procurement, program, finance, support, and other expertise around a product or work package. |
| ISA | International Standard Atmosphere: A reference atmospheric model defining standard pressure, temperature, density, and their variation with altitude for aircraft design and performance comparisons. |
| ISTAT | International Society of Transport Aircraft Trading: A professional association serving the commercial aircraft trading, leasing, financing, manufacturing, and appraisal community. |
| J | |
| JCAB | Japan Civil Aviation Bureau: Japan’s civil aviation authority and an important validating regulator for commercial aircraft delivered to Japanese operators. |
| L | |
| LCA | Large Commercial Aircraft: A market and policy category covering larger passenger and freight aircraft produced for airline service, often used in industry analysis, trade matters, and competitive assessments. |
| LCC | Life-Cycle Cost: The total cost incurred across development, acquisition, operation, support, modification, and retirement. It informs design trade-offs and customer value propositions beyond initial purchase price. |
| LCC | Low-Cost Carrier: An airline model emphasizing simplified fleets, high utilization, dense seating, rapid turnarounds, and tightly controlled unit costs. These priorities strongly influence aircraft selection and configuration. |
| LFL | Landing Field Length: The runway length required to land and stop under defined aircraft, runway, weather, and regulatory conditions. It is a key airport-compatibility and performance measure. |
| LOPA | Layout of Passenger Accommodations: The controlled cabin layout showing seats, aisles, exits, monuments, lavatories, galleys, and other interior features for a specific customer configuration. |
| LTAG | Long-Term Aspirational Goal: The international civil aviation goal of net-zero carbon emissions from international aviation by 2050, informing technology road maps, fuel compatibility, and fleet strategy. |
| LTO | Landing and Take-Off Cycle: A standardized operating cycle used to assess aircraft-engine emissions around airports, covering defined taxi, takeoff, climb-out, and approach modes. |
| M | |
| MAC | Mean Aerodynamic Chord: A representative wing chord used in aerodynamic analysis and to express center-of-gravity position consistently across loading conditions. |
| MBD | Model-Based Definition: A product-definition approach in which an authoritative three-dimensional model contains the geometry, dimensions, tolerances, annotations, and other manufacturing information needed to build and inspect the product. |
| MBE | Model-Based Enterprise: An operating model that uses controlled digital product models across engineering, manufacturing, quality, suppliers, certification, and support instead of relying primarily on drawings and disconnected documents. |
| MBOM | Manufacturing Bill of Materials: The product structure organized according to how an aircraft or assembly will actually be built, including production groupings, consumables, and installation sequence needs. |
| MBSE | Model-Based Systems Engineering: The formalized use of linked models to manage requirements, functions, architecture, interfaces, behavior, verification, and traceability across a complex aircraft program. |
| MCAI | Mandatory Continuing Airworthiness Information: Mandatory safety information issued by an airworthiness authority, generally requiring inspections, modifications, limitations, or other corrective actions for affected products. |
| MEL | Minimum Equipment List: An operator-specific, authority-approved document identifying equipment that may be temporarily inoperative for dispatch under stated conditions, procedures, and time limits. |
| MES | Manufacturing Execution System: A digital system that controls and records shop-floor work, instructions, labor, material movement, inspections, genealogy, and production status. |
| MEW | Manufacturer’s Empty Weight: The weight of the completed aircraft as delivered from manufacturing, including structure, powerplants, systems, furnishings, and installed equipment but excluding defined operational items and payload. |
| MLW | Maximum Landing Weight: The highest approved aircraft weight for normal landing, established by structural, performance, handling, and certification constraints. |
| MMEL | Master Minimum Equipment List: The authority-approved master document developed for an aircraft type that establishes the basis from which operators create their own dispatch-relief lists. |
| MMO | Maximum Operating Mach Number: The highest Mach number permitted in normal operation, protecting the aircraft from adverse compressibility, loads, flutter, stability, and control effects. |
| MOC | Means of Compliance: The agreed method—such as analysis, test, inspection, simulation, or similarity—used to demonstrate that a design satisfies an applicable certification requirement. |
| MRB | Maintenance Review Board: An authority-led process involving manufacturers, operators, and regulators to develop and approve the initial scheduled maintenance program for a new aircraft type. |
| MRB | Material Review Board: The authorized quality and engineering function that evaluates nonconforming material and determines an approved disposition such as rework, repair, use-as-is, or scrap. |
| MRBR | Maintenance Review Board Report: The regulator-approved report containing the initial minimum scheduled maintenance and inspection requirements developed for an aircraft type. |
| MRL | Manufacturing Readiness Level: A scale used to assess whether manufacturing technology, processes, suppliers, tooling, quality controls, and capacity are mature enough for the next program phase. |
| MSG-3 | Maintenance Steering Group—3: The industry methodology used by operators and manufacturers to develop scheduled maintenance tasks through structured analysis of systems, structures, zonal areas, and failure consequences. |
| MSN | Manufacturer Serial Number: The unique number assigned by the manufacturer to identify and track an individual aircraft throughout production, delivery, operation, and configuration changes. |
| MTOW | Maximum Take-Off Weight: The highest approved aircraft weight at the start of the takeoff roll, limited by structural, performance, environmental, and certification considerations. |
| MZFW | Maximum Zero Fuel Weight: The highest approved aircraft weight excluding usable fuel. It protects the wing and fuselage from excessive bending loads created by payload distribution. |
| N | |
| NAA | National Aviation Authority: A country’s governmental body responsible for civil aviation regulation, certification, approvals, and safety oversight. |
| Nadcap | National Aerospace and Defense Contractors Accreditation Program: The aerospace industry’s cooperative accreditation program for special processes and products such as heat treatment, coatings, welding, composites, and non-destructive testing. |
| NB | Narrowbody: A common market term for a single-aisle commercial aircraft, typically optimized for short- to medium-haul service and high production volumes. |
| NCR | Nonconformance Report: A controlled record documenting a product or process that fails to meet requirements, along with containment, evaluation, disposition, and corrective-action information. |
| NEF | Nonessential Equipment and Furnishings: Items installed for convenience, comfort, or appearance that may be inoperative, damaged, or missing without affecting safe operation, subject to an approved control program. |
| NRC | Non-Recurring Cost: One-time program expenditure for activities such as development, certification, tooling, testing, and industrialization rather than unit-by-unit production. |
| NRE | Non-Recurring Engineering: One-time engineering effort needed to develop, integrate, analyze, test, certify, or customize a product before or outside repetitive production. |
| nvPM | Non-Volatile Particulate Matter: Solid exhaust particles that remain after volatile material is removed under specified measurement conditions. Their mass and number are regulated for qualifying aircraft engines. |
| O | |
| OASIS | Online Aerospace Supplier Information System: The global database containing aerospace quality-management certification information, audit results, and approved certification-body records used in supplier oversight. |
| ODA | Organization Designation Authorization: A United States regulatory program authorizing a qualified organization to perform specified certification functions on the regulator’s behalf while remaining subject to oversight. |
| OEB | Operational Evaluation Board: A European regulatory board that evaluates pilot type ratings, training, checking, currency, and operational suitability data for an aircraft type. |
| OEE | Overall Equipment Effectiveness: A manufacturing measure combining availability, performance rate, and quality yield to show how effectively equipment or a production asset is being used. |
| OEM | Original Equipment Manufacturer: The company responsible for producing and delivering the original aircraft or major equipment, typically while coordinating a large network of risk-sharing partners and suppliers. |
| OEW | Operating Empty Weight: The weight of an aircraft prepared for operation but excluding usable fuel and payload. It is a major determinant of payload-range capability and operating efficiency. |
| OTD | On-Time Delivery: The proportion of items delivered by the contractual or required date. It is a core measure of supplier reliability and production-system performance. |
| P | |
| PC | Production Certificate: United States regulatory approval authorizing a manufacturer to produce duplicate products that conform to an approved design under an accepted production-quality system. |
| PCR | Pavement Classification Rating: An International Civil Aviation Organization rating expressing the load-carrying capacity of airport pavement. Comparing it with the aircraft rating supports unrestricted-operating assessments. |
| PDM | Product Data Management: The controlled management of product structures, design files, revisions, approvals, effectivity, and engineering changes throughout development and production. |
| PDP | Pre-Delivery Payment: A contractually scheduled customer payment made before aircraft delivery. These payments are important to manufacturer cash flow and create financing requirements for airlines and lessors. |
| PDR | Preliminary Design Review: A formal review confirming that the preliminary design satisfies allocated requirements and is sufficiently mature to proceed into detailed design. |
| PFMEA | Process Failure Mode and Effects Analysis: A structured assessment of potential manufacturing or assembly process failures, their effects and causes, and the controls needed to reduce production risk. |
| PLM | Product Lifecycle Management: The processes and digital platform used to control requirements, product definition, configurations, changes, approvals, and related information throughout the aircraft lifecycle. |
| PMI | Product and Manufacturing Information: Dimensions, tolerances, materials, finishes, notes, and other production requirements embedded in or associated with a three-dimensional product model. |
| POA | Production Organisation Approval: European regulatory approval confirming that an organization can manufacture products, parts, and appliances that conform to approved design data and are in a condition for safe operation. |
| PPAP | Production Part Approval Process: A structured submission demonstrating that a supplier understands all design requirements and that its production process can repeatedly manufacture conforming parts at the required rate. |
| PPM | Parts per Million: A normalized quality measure expressing the number of defective parts for every million parts delivered or produced. |
| PRA | Particular Risk Analysis: A safety assessment of external or localized hazards such as fire, tire burst, rotor burst, bird strike, lightning, or fluid leakage that could affect multiple aircraft systems. |
| PRR | Production Readiness Review: A formal assessment of whether designs, processes, tooling, facilities, suppliers, staffing, quality controls, and material plans are ready for production or a rate increase. |
| PSCP | Project-Specific Certification Plan: A detailed agreement between an applicant and the United States aviation regulator describing the certification basis, project schedule, responsibilities, compliance methods, and oversight approach. |
| PSSA | Preliminary System Safety Assessment: An analysis performed during architectural design to determine whether proposed system structures, independence, redundancy, and assurance allocations can satisfy safety objectives. |
| Q | |
| QMS | Quality Management System: The documented governance, processes, responsibilities, controls, records, and improvement mechanisms used to ensure products and services consistently satisfy requirements. |
| QRH | Quick Reference Handbook: An easily accessible flight-deck document containing checklists and concise procedures for normal, abnormal, and emergency situations. |
| R | |
| RC | Recurring Cost: The cost incurred repeatedly for each aircraft or production unit, including direct material, labor, supplier content, and allocable manufacturing activity. |
| RCCA | Root Cause and Corrective Action: A disciplined process for identifying the underlying cause of a problem, implementing durable corrective measures, and verifying that recurrence has been prevented. |
| RPK | Revenue Passenger Kilometer: An airline traffic measure calculated by multiplying paying passengers by kilometers flown. It is widely used in demand forecasting and long-term fleet planning. |
| RSP | Risk-Sharing Partner: A major program supplier that assumes defined development investment, technical scope, schedule exposure, and sometimes market risk in exchange for long-term production participation. |
| RVSM | Reduced Vertical Separation Minimum: Airspace standards permitting one-thousand-foot vertical separation at specified high-altitude flight levels. Aircraft must meet demanding altitude-measurement and control requirements to qualify. |
| S | |
| SAF | Sustainable Aviation Fuel: Aviation fuel produced from eligible non-fossil or recycled-carbon pathways and meeting applicable jet-fuel specifications. Compatibility, emissions performance, availability, and cost influence aircraft and fleet decarbonization plans. |
| SAR | Specific Air Range: The still-air distance an aircraft travels per unit of fuel consumed under defined conditions. It is a core measure of cruise efficiency. |
| SARP | Standards and Recommended Practices: International civil aviation provisions adopted in convention annexes to promote globally consistent safety, operations, environmental protection, and interoperability. |
| SB | Service Bulletin: A manufacturer-issued document providing approved instructions for inspection, modification, repair, replacement, or product improvement on in-service aircraft or equipment. |
| SC | Special Condition: An additional airworthiness requirement issued when existing regulations do not contain adequate standards for a novel or unusual design feature. |
| SCAR | Supplier Corrective Action Request: A formal request requiring a supplier to contain a nonconformity, determine its root cause, implement corrective action, and demonstrate effectiveness. |
| SCN | Specification Change Notice: A controlled commercial and technical document used to define, price, approve, and incorporate a customer-requested change to an aircraft specification or configuration. |
| SFAR | Special Federal Aviation Regulation: A United States aviation rule addressing a specific safety, operational, technical, or transitional circumstance outside the normal structure of standing requirements. |
| SFE | Seller-Furnished Equipment: Equipment selected and procured by the aircraft manufacturer as part of the delivered aircraft specification, with the manufacturer managing supplier and integration responsibilities. |
| SIL | Service Information Letter: A manufacturer communication providing operators with technical information, recommendations, clarifications, or planning guidance that does not require the formal instructions of a service bulletin. |
| SMS | Safety Management System: A structured, organization-wide approach to managing safety risk through policy, accountabilities, hazard identification, assurance, and promotion. |
| SOI | Stage of Involvement: A planned regulatory oversight point used to evaluate development-assurance processes, data, implementation, verification, and compliance evidence at selected project stages. |
| SPC | Statistical Process Control: The use of statistical methods and control charts to distinguish normal process variation from special causes and maintain stable, capable production. |
| SQAR | Supplier Quality Assurance Requirements: Contractual quality requirements specifying the systems, controls, records, notifications, approvals, and performance expected from suppliers. |
| SRR | System Requirements Review: A formal review confirming that system requirements are complete, consistent, traceable, feasible, verifiable, and aligned with aircraft-level needs. |
| SSA | System Safety Assessment: The final system-level analysis demonstrating that the implemented architecture and design satisfy quantitative and qualitative safety requirements. |
| STEP | Standard for the Exchange of Product Model Data: An international family of standards enabling neutral exchange and long-term representation of digital product-definition data across engineering and manufacturing systems. |
| T | |
| TC | Type Certificate: Regulatory approval confirming that an aircraft, engine, or propeller type design complies with applicable airworthiness requirements. |
| TCCA | Transport Canada Civil Aviation: The Canadian authority responsible for civil aircraft certification, aviation safety regulation, and oversight, and a major validating authority for commercial aircraft. |
| TCDS | Type Certificate Data Sheet: The official regulatory record summarizing an approved type design’s models, engines, limitations, operating parameters, certification basis, and other defining data. |
| TIA | Type Inspection Authorization: A United States regulatory authorization defining the conformity inspections, ground tests, and flight tests needed for official evaluation of a certification project. |
| TIP | Technical Implementation Procedures: Detailed procedures under a bilateral safety agreement describing how authorities cooperate, divide responsibilities, and accept certification or production findings. |
| TOFL | Take-Off Field Length: The runway distance required for takeoff under specified aircraft, atmospheric, runway, and regulatory conditions. It is a primary aircraft performance and airport-compatibility measure. |
| TRL | Technology Readiness Level: A scale for assessing technology maturity from basic principles through demonstration in an operationally relevant environment, supporting investment and program-insertion decisions. |
| TSFC | Thrust-Specific Fuel Consumption: The rate of fuel consumption per unit of engine thrust. It is a key propulsion-efficiency input to aircraft range, emissions, and operating-cost analysis. |
| U | |
| ULD | Unit Load Device: A standardized aircraft container or pallet used to consolidate baggage, freight, and mail. Aircraft design must accommodate its dimensions, loads, restraint, handling, and fire-protection requirements. |
| V | |
| V&V | Verification and Validation: The complementary processes of confirming that a design meets specified requirements and that those requirements and the resulting product satisfy intended use and stakeholder needs. |
| VLA | Very Large Aircraft: An industry and regulatory category for the largest commercial aeroplanes, whose size can drive special airport, evacuation, wake, structural, and infrastructure considerations. |
| VMO | Maximum Operating Limit Speed: The highest calibrated airspeed permitted in normal operation below the altitude where the Mach-number limit becomes more restrictive. |
| W | |
| WB | Widebody: A common market term for a twin-aisle commercial aircraft, generally used for higher-capacity, longer-range passenger or freight operations. |
| WBM | Weight and Balance Manual: Manufacturer documentation containing aircraft weighing, loading, balance, moment, and center-of-gravity information needed for safe operational loading. |
| WFD | Widespread Fatigue Damage: The simultaneous presence of fatigue cracks at multiple structural locations such that the structure can no longer meet required residual-strength assumptions. Prevention drives design, testing, inspection, and life-limit decisions. |
| Z | |
| ZSA | Zonal Safety Analysis: A systematic review of each aircraft zone to identify installation interactions, environmental hazards, maintenance errors, and common events that could compromise multiple systems. |