FAA Advisory Circulars for Airport Pavement

What are FAA Advisory Circulars for Airport Pavement?

FAA Advisory Circulars (ACs) are a formal, agency-wide document system established in 1962 under FAA Order 1320.46 that provides guidance, methods, procedures, and practices acceptable to the FAA Administrator for complying with regulations and grant requirements. For airport pavement engineering, ACs represent the authoritative technical framework governing how pavements at civil airports in the United States are designed, constructed, evaluated, maintained, and reported. These documents carry significant legal weight because compliance with AC standards is mandatory for all projects funded through the Airport Improvement Program (AIP) or Passenger Facility Charge (PFC) Program under Grant Assurance No. 34 (“Policies, Standards, and Specifications”) and PFC Assurance No. 9 (“Standards and Specifications”).

The AC numbering system follows a standardized format: AC 150/XXXX-XX, where 150 designates the Airports series, the four-digit number identifies the specific subject area, and the trailing letter indicates the version (e.g., AC 150/5320-6G is the seventh version of the pavement design AC). The FAA Airports Office (AAS-100) initiates, maintains, and revises these ACs to reflect current research, technological advances, and industry best practices. The FAA Order 1320.46C (Advisory Circular System) establishes the procedures for preparing, processing, and delivering ACs, including coordination requirements, clearance procedures, and standards for format, writing, and accessibility.

Each AC typically contains purpose, cancellation, application, effective date, and principal changes sections, followed by detailed technical chapters. The application section is critical because it defines whether the guidance is recommended (general industry best practice) or mandatory (required for federally funded projects or Part 139 certificated airports). The AC system emphasizes the need to keep documents current, and the FAA has established an online database at www.faa.gov/airports/resources/advisory_circulars/ where all active, cancelled, and draft ACs are published and searchable by document number, title, status, or subject area.

The FAA Advisory Circular System

The FAA Advisory Circular system was established in 1962 as a mechanism to deliver advisory material to FAA customers, industry, the aviation community, and the public through a single, uniform, agency-wide framework. Before the AC system was formalized, the FAA issued guidance through a fragmented collection of memoranda, bulletins, and informal letters, creating inconsistencies in how regulatory requirements were interpreted and applied across different FAA offices and regions.

FAA Order 1320.46D (FAA Advisory Circular System) governs the AC system and sets forth detailed procedures for preparing, processing, and delivering ACs. The order establishes that ACs serve the following purposes: providing guidance such as methods, procedures, and practices acceptable to the Administrator for complying with regulations and grant requirements; offering explanations of regulations, other guidance material, best practices, or information useful to the aviation community; and communicating technical standards that the FAA considers essential for ensuring safety and consistency across the national airport system.

Key provisions of the AC system include the AC numbering system (defined in Appendix 1 of Order 1320.46C), which assigns a base number that corresponds to the subject matter followed by an alphabetical suffix indicating the version sequence. For the Airports series, the base number is 150, followed by a four-digit code and optional suffix. The system requires plain language writing, mandates compliance with Section 508 accessibility standards for web-published documents, and emphasizes the need to keep ACs current through regular revision cycles.

The processing and distribution of ACs follows a structured workflow that includes drafting, internal coordination, external comment periods (when applicable), final review, approval, and publication. The FAA Office of Cost and Performance Management maintains the central AC database and provides guidance on processing procedures. Authors within individual FAA offices (such as the Office of Airport Safety and Standards for pavement-related ACs) are responsible for drafting content, coordinating with reviewing offices, obtaining Office of the Chief Counsel clearance when needed, and ensuring the final document meets quality and formatting standards.

AC Categories Relevant to Airport Pavement

The FAA issues ACs across multiple subject areas, but the following Airports series (150/XXXX) ACs are the most directly relevant to airport pavement engineering:

AC 150/5320-6G — Airport Pavement Design and Evaluation

AC 150/5320-6G (issued June 7, 2021) is the primary FAA document governing the structural design and evaluation of pavements used by aircraft at civil airports in the United States. This AC cancels and replaces the previous version (AC 150/5320-6F) and represents the culmination of decades of FAA research into pavement behavior, aircraft loading effects, and material performance. The AC provides detailed guidance on the design of flexible pavements (asphalt), rigid pavements (portland cement concrete), and overlays (asphalt over asphalt, asphalt over concrete, concrete over concrete, and concrete over asphalt).

The design methodology prescribed by AC 150/5320-6G implements layered elastic theory for flexible pavement design and three-dimensional finite element analysis for rigid pavement design, both executed through the FAARFIELD (FAA Rigid and Flexible Iterative Elastic Layer Design) software package. FAARFIELD is the standard FAA pavement design software and is distributed free of charge by the FAA Airport Technology Research and Development Branch. The AC requires that all design calculations be performed using the current version of FAARFIELD, which incorporates the structural models, failure criteria, and material characterization protocols specified in the document.

The scope of AC 150/5320-6G includes the following critical design parameters:

Traffic Analysis — The AC provides guidance on determining the design traffic in terms of annual departures for each aircraft type expected to use the pavement. Traffic is categorized by design aircraft (the most demanding aircraft that will use the pavement regularly) and covered aircraft (other aircraft in the traffic mix). The cumulative damage factor (CDF) method is used to convert the mixed traffic into equivalent passes of the design aircraft. For flexible pavements, traffic is expressed as equivalent annual departures of the design aircraft, while rigid pavement design uses a similar approach with different damage models.

Subgrade Characterization — The AC defines procedures for characterizing subgrade support through the California Bearing Ratio (CBR) for flexible pavements and the modulus of subgrade reaction (k) for rigid pavements. The AC specifies that subgrade samples shall be tested in accordance with ASTM D1883 for CBR and AASHTO T222 or ASTM D1196 for k-value determination. The design subgrade strength is typically based on the average (for flexible) or worst-case seasonal (for rigid) values, considering the effects of moisture variation, frost action, and other environmental factors.

Material Properties — AC 150/5320-6G specifies material properties for each pavement layer, including the resilient modulus (Mr) for granular base and subbase materials, the dynamic modulus (E)* for asphalt concrete, and the flexural strength (MR) for portland cement concrete. The AC provides default material properties for use when site-specific testing data is not available, as well as guidance on laboratory and field testing protocols for obtaining project-specific values.

Design Life — The AC specifies a minimum 20-year design life for new pavement construction and a 10-year design life for most overlay projects. However, the AC acknowledges that longer design lives may be economically justified for high-traffic pavements and provides guidance on extending the design life through additional structural capacity.

The evaluation component of AC 150/5320-6G addresses the determination of existing pavement structural capacity for overlay design, pavement strength reporting (PCN), and pavement management purposes. Evaluation methods include nondestructive testing (NDT) using the Falling Weight Deflectometer (FWD), destructive testing through coring and materials testing, and visual condition surveys. The AC provides specific guidance on interpreting FWD deflection data for back-calculation of layer moduli and remaining structural life.

The FAARFIELD software, as the computational engine for AC 150/5320-6G, incorporates failure models calibrated to airport pavement performance data. For flexible pavements, the failure criterion is based on the horizontal tensile strain at the bottom of the asphalt layer (fatigue cracking) and the vertical compressive strain at the top of the subgrade (rutting). For rigid pavements, the failure criterion is based on the maximum tensile stress at the edge of the concrete slab (fatigue cracking). The software accounts for the wander of aircraft traffic across the pavement width and the number of load repetitions at various lateral positions.

AC 150/5370-10H — Standard Specifications for Construction of Airports

AC 150/5370-10H (latest version with ongoing Change Notifications) contains the standard specifications for materials and methods used for construction on airports. This AC is arguably the most widely used FAA document among airport construction engineers and inspectors because it provides the enforceable specification language that must be incorporated into contract documents for all AIP and PFC funded projects. The AC is organized into Items (each designated by a letter-number code such as P-401, P-501) that cover specific construction activities, materials, and quality control requirements.

The pavement-related items in AC 150/5370-10H include:

Item P-401 (Plant Mix Bituminous Pavements) is the most detailed and technically sophisticated pavement specification in the AC. It incorporates Superpave mix design methodology (per AASHTO R 35 and AASHTO M 323) using the Superpave Gyratory Compactor (SGC) for laboratory compaction. The P-401 specification defines three gradation types (Gradation 1 — 19.0 mm NMAS, Gradation 2 — 12.5 mm NMAS, and Gradation 3 — 9.5 mm NMAS) and specifies Performance Grade (PG) binders selected based on airport climate with additional grade bumping for high tire pressure aircraft. Quality control and acceptance testing for P-401 uses Percent Within Limits (PWL) methodology with pay factors based on the percentage of test results falling within specification limits.

Item P-501 (Portland Cement Concrete Pavement) covers rigid pavement construction including plain, reinforced, and continuously reinforced concrete pavements. The specification addresses concrete mix design (minimum cement content, maximum water-cement ratio, air content requirements), jointing (contraction, expansion, and construction joints), load transfer devices (dowel bars and tie bars), curing methods, and acceptance testing. The P-501 specification requires flexural strength testing (ASTM C78 or C293) for acceptance, with minimum design flexural strengths typically ranging from 550 to 700 psi depending on traffic loading.

The AC also includes detailed quality control/quality assurance (QC/QA) provisions that require the contractor to develop and implement a comprehensive QC plan. The QC/QA section specifies random sampling procedures, statistical analysis methods, dispute resolution protocols, and payment adjustment formulas based on the contractor’s demonstrated quality level. For P-401 projects, the FAA now requires a pre-construction QC/QA workshop involving the engineer, resident project representative, contractor, subcontractors, testing laboratories, and owner’s representative before any paving operations begin.

Change Notifications to AC 150/5370-10H are issued periodically to update individual specification items without requiring a full revision of the entire document. These change notifications (designated as Change 1, Change 2, etc.) address specific technical updates, new materials, or revised testing protocols. Engineers and contractors must verify that they are using the most current version of each item, as listed on the FAA Airport Construction Standards website.

AC 150/5380-7B — Airport Pavement Management Program (PMP)

AC 150/5380-7B (issued October 10, 2014) discusses the Airport Pavement Management Program (PMP) concept, its essential components, and how it is used to make cost-effective decisions about pavement maintenance and rehabilitation. This AC is the foundational document for pavement inspection and condition assessment at US airports because it establishes the framework for collecting, analyzing, and managing pavement condition data.

The PMP concept defined in AC 150/5380-7B consists of four essential components:

Pavement Inventory — A comprehensive database of all pavement areas (runways, taxiways, aprons, shoulders) that includes physical characteristics such as dimensions, pavement type (flexible or rigid), construction date, layer thicknesses, material properties, and historical maintenance and rehabilitation activities. The inventory serves as the foundational data layer for all PMP activities.

Pavement Condition Surveys — The systematic collection of pavement condition data using standardized inspection methodologies. The AC specifically references ASTM D5340 (Standard Test Method for Airport Pavement Condition Index Surveys) for conducting Pavement Condition Index (PCI) surveys. The PCI method involves dividing pavements into sample units, conducting visual inspections to identify and quantify distress types (cracking, rutting, raveling, weathering, joint spalling, faulting, etc.), and calculating a numerical index from 0 (failed) to 100 (excellent) that represents the pavement’s structural integrity and surface condition. The AC specifies different survey frequencies based on traffic levels, with annual PCI surveys recommended for primary commercial service airports.

Condition Prediction Models — Mathematical models that predict how pavement condition will deteriorate over time under projected traffic and environmental conditions. These models allow airport managers to forecast future condition, identify the optimal timing for maintenance and rehabilitation interventions, and develop long-term capital improvement programs. The AC provides guidance on developing family curves (deterioration curves for groups of similar pavement sections) or project-level models using historical PCI data.

Decision Support Tools — Analytical tools (ranging from simple spreadsheets to specialized pavement management software) that compare the costs and benefits of alternative maintenance and rehabilitation strategies and identify the most cost-effective approach for each pavement section. The AC discusses life-cycle cost analysis (LCCA) principles and minimum acceptable condition thresholds that trigger rehabilitation or reconstruction.

The AC establishes a minimum acceptable PCI of 70 for primary (commercial service) runways and 55 for other pavement areas, though individual airport operators may set higher thresholds based on their operational requirements and risk tolerance. Pavements falling below these thresholds require rehabilitation or reconstruction to maintain safety and operational compliance under 14 CFR Part 139.

AC 150/5380-7B is closely linked to AC 150/5380-6C (Guidelines and Procedures for Maintenance of Airport Pavements), which provides detailed guidance on preventive maintenance, corrective maintenance, and rehabilitation techniques. While AC 150/5380-7B addresses the management and decision-making framework, AC 150/5380-6C addresses the specific repair techniques (crack sealing, patching, overlay, surface treatment, etc.) and maintenance scheduling.

AC 150/5320-12C — Measurement, Construction, and Maintenance of Skid-Resistant Pavement Surfaces

AC 150/5320-12C (issued October 2007, with multiple Change Notifications through Change 9 in June 2025) contains guidelines and procedures for the design and construction of skid-resistant pavement, pavement evaluation using friction measuring equipment, and maintenance of high skid-resistant pavement surfaces. This AC is critical for runway safety because it addresses the friction characteristics of pavement surfaces that directly affect aircraft braking performance, particularly under wet or contaminated conditions.

The AC establishes the FAA friction measurement program, which requires airports certificated under 14 CFR Part 139 to conduct friction surveys of runways at specified frequencies using FAA-approved continuous friction measuring equipment (CFME) . The AC specifies the following key friction parameters:

Friction Thresholds — The AC defines three friction categories based on the Mu (μ) friction coefficient measured at the test speed (typically 40 mph or 65 km/h for runways):

• Design Level — The friction value specified for new pavement construction or surface treatment (minimum target value)
• Maintenance Level — The friction value at which a pavement surface requires evaluation and consideration of corrective action
• Alert Level — The friction value at which the airport operator must take immediate action, which may include runway closure or surface treatment

The specific friction thresholds vary by CFME type and are published in the AC’s appendices. For typical Mu-meter testing at 40 mph, a Design Level of 0.5, a Maintenance Level of 0.4, and an Alert Level of 0.3 are commonly referenced, though these values depend on the equipment type and test speed.

Friction Testing Equipment — The AC provides detailed specifications for FAA-approved CFME, including the Mu-meter (trailer-mounted continuous friction measuring device), the Saab Friction Tester (SFT) , the Griptester, the Surface Friction Tester (SFT) , and other equipment types. Each equipment type has specific calibration requirements, test protocols, and correlation equations that must be used to standardize friction measurements across different devices.

Runway Surface Texture — The AC addresses the relationship between macrotexture (large-scale surface irregularities that provide water drainage paths) and microtexture (small-scale surface asperities that provide direct tire-pavement contact). The AC references ASTM E965 (Measuring Pavement Macrotexture Depth Using a Volumetric Technique — the “sand patch” test) and ASTM E2157 (Determining Pavement Macrotexture Using the Outflow Meter) for texture measurement. New runway surfaces are required to have a minimum mean texture depth (MTD) that ensures adequate water drainage and friction under wet conditions.

Draft AC 150/5320-12D is currently under development and will replace the existing AC 150/5320-12C. The draft incorporates updated names and addresses of FAA-approved CFME manufacturers, revised friction thresholds based on recent research, updated guidance on grooving and porous friction course (PFC) construction, and enhanced guidance on friction data analysis and trend monitoring.

AC 150/5320-17 — Airfield Pavement Surface Evaluation and Rating Manuals

AC 150/5320-17 (now cancelled) provided guidance on understanding and rating the surface condition of flexible and rigid airfield pavements and provided a simple system to visually rate pavement condition on a scale ranging from excellent to failed. Although this AC has been cancelled, its methodology continues to be referenced in practice because it established the foundation for visual pavement condition assessment at US airports.

The AC’s rating system classified pavement condition into six categories:

• Excellent — No visible distress, pavement is like new
• Very Good — Minor distress present but within acceptable limits
• Good — Distress present but not affecting pavement performance significantly
• Fair — Significant distress present, pavement beginning to show structural deterioration
• Poor — Extensive distress, pavement requires rehabilitation
• Failed — Pavement has failed and requires reconstruction

The AC described types and causes of distress for both flexible pavements (cracking, rutting, raveling, bleeding, patching, settlement) and rigid pavements (cracking, joint spalling, faulting, scaling, patching, pumping, blowups). Each distress type was illustrated with photographs and described with cause mechanisms to help inspectors identify and classify distresses correctly.

While AC 150/5320-17 has been cancelled, its visual rating concepts have been superseded by the more quantitative Pavement Condition Index (PCI) methodology specified in ASTM D5340 and referenced by AC 150/5380-7B. The PCI method provides a more systematic, repeatable, and statistically valid approach to pavement condition assessment than the earlier visual rating system.

AC 150/5335-5C — Standardized Method of Reporting Airport Pavement Strength — PCN

AC 150/5335-5C (issued August 14, 2014) provides guidance for using the standardized International Civil Aviation Organization (ICAO) method to report airport runway, taxiway, and apron pavement strength. This AC implements the Aircraft Classification Number — Pavement Classification Number (ACN-PCN) method, which has been developed and adopted as an international standard for exchanging pavement strength rating information.

The ACN-PCN system requires ICAO member states to report aerodrome-related aeronautical data, including pavement strength, in a standardized format. The AC applies to pavements with bearing strengths of 12,500 pounds (5,700 kg) or greater and affects data elements reported on FAA Form 5010 (Airport Master Record).

The AC defines the following key concepts:

Aircraft Classification Number (ACN) — A number expressing the relative effect of an aircraft at a given weight and configuration on a pavement for a specified subgrade strength category. ACN is calculated using COMFAA (the FAA software program for pavement strength evaluation) per ICAO procedures, considering aircraft gear geometry, tire pressure, load distribution, and weight.

Pavement Classification Number (PCN) — A number expressing the load-carrying capacity of a pavement for unrestricted operations. PCN is determined using one of four methods: Technical Evaluation (using pavement layer thicknesses and material properties), Using Aircraft Method (based on the operation of known aircraft), Empirical Method (using local experience), or Engineering Judgment (when other methods are not feasible). The Technical Evaluation method is preferred for AIP-funded projects.

PCN Reporting Format — The standardized reporting format includes: PCN value, pavement type (R for rigid, F for flexible), subgrade strength category (A — high, B — medium, C — low, D — ultra-low), tire pressure category (W — unlimited ≤ 1.50 MPa, X — high ≤ 1.00 MPa, Y — medium ≤ 0.50 MPa, Z — low ≤ 0.25 MPa), and evaluation method (T — technical, U — using aircraft, E — empirical, J — engineering judgment).

COMFAA Software — The FAA maintains and distributes COMFAA as the standard software for ACN and PCN calculation. The software allows users to input pavement layer data (thicknesses, material types, moduli), compute PCN values using the Technical Evaluation method, and generate standardized PCN reports. The current COMFAA version includes support spreadsheets with updated examples for flexible and rigid pavement technical evaluations.

The AC requires that all public-use paved runways at Part 139 certificated airports be assigned PCN data, and that PCN data be updated upon completion of AIP or PFC-funded pavement projects. PCN data is published in the Airport/Facility Directory (A/FD) and other aeronautical information publications to inform pilots and air carriers of pavement bearing capacity limitations.

FAA Advisory Circulars vs. ICAO Standards

FAA Advisory Circulars and International Civil Aviation Organization (ICAO) standards serve complementary but distinct roles in airport pavement engineering. Understanding the relationship between these two frameworks is essential for airport engineers, particularly those working at airports that serve international traffic or receive international funding.

FAA Advisory Circulars define the national standards for airport pavement design, construction, and maintenance within the United States. FAA standards are developed through the FAA’s regulatory processes and are enforceable under US law through 14 CFR Part 139 (Certification of Airports) and the Airport Improvement Program (AIP) grant assurances. FAA ACs are typically more detailed and prescriptive than ICAO standards, providing specific material specifications, test methods, acceptance criteria, and construction procedures.

ICAO Standards (primarily Annex 14 — Aerodromes and the Aerodrome Design Manual Doc 9157, Part 3 — Pavements) define the international minimum standards for aerodrome design and operation adopted by ICAO’s 193 member states. ICAO standards are broader and more performance-based, specifying required outcomes rather than detailed methods for achieving those outcomes. ICAO Annex 14 standards are enforceable through each member state’s national regulations — in the US, through FAA regulations and ACs.

For pavement strength reporting, FAA AC 150/5335-5C explicitly adopts the ICAO standardized ACN-PCN method, ensuring that US airports report pavement strength in a format compatible with international standards. The FAA’s COMFAA software calculates ACN using ICAO procedures, and the PCN reporting format (pavement type, subgrade category, tire pressure category, evaluation method) follows the ICAO standard precisely.

Where differences exist between FAA and ICAO standards, the FAA’s standards typically exceed ICAO minimum requirements due to the higher aircraft traffic density, larger aircraft sizes, and more demanding operational environment at US commercial service airports. For example, FAA friction requirements (AC 150/5320-12C) are more detailed and specify more frequent testing intervals than ICAO Annex 14 requirements. Similarly, FAA PCI survey requirements (AC 150/5380-7B) are more comprehensive than ICAO’s general pavement condition monitoring guidance.

How FAA ACs Define Pavement Inspection Criteria

FAA Advisory Circulars establish the technical framework for airport pavement inspection through a layered system of documents that collectively define what to inspect, how to inspect it, how to evaluate the results, and what actions to take based on those results.

Pavement Condition Index (PCI) Surveys

The primary inspection methodology specified by FAA ACs is the Pavement Condition Index (PCI) survey per ASTM D5340, as referenced by AC 150/5380-7B. The PCI method provides a numerical rating from 0 (failed) to 100 (excellent) based on the type, severity, and density of pavement distresses observed during visual inspection.

The PCI survey process divides the pavement network into branches (runways, taxiways, aprons), sections (uniform pavement segments within each branch), and sample units (approximately 20 m² or 5,000 ft² areas within each section). Inspectors walk each sample unit and identify distress types from standard categories defined in ASTM D5340, including:

• Flexible pavement distresses: Fatigue (alligator) cracking, block cracking, joint reflection cracking, longitudinal and transverse cracking, rutting, depressions, corrugation, shoving, weathering, raveling, bleeding, patching, and polishing
• Rigid pavement distresses: Corner break, divided slab, durability (D) cracking, linear cracking, scaling, spalling (joint and corner), joint seal damage, pumping, patching, blowup, popouts, and faulting

Each distress is rated for severity (low, medium, high) and quantified by density (percentage of the sample unit area affected). The PCI is calculated using deduct value curves that convert each distress-severity-density combination into a numerical deduct value (from 0 to 100), with higher deducts indicating more severe distress. The total deduct value is subtracted from 100 to obtain the sample unit PCI.

Friction Surveys

Friction surveys per AC 150/5320-12C use continuous friction measuring equipment (CFME) to measure the friction coefficient of runway surfaces under wet conditions. The AC specifies:

• Test speed: Typically 40 mph (65 km/h) for runways, 25 mph (40 km/h) for taxiways
• Water depth: 0.02 to 0.04 inches (0.5 to 1.0 mm) on the test surface
• Test frequency: Quarterly for primary runways at Part 139 certificated airports, with monthly testing recommended during winter months
• Data reporting: Friction values averaged over each runway third (touchdown zone, mid-section, rollout zone)

The AC defines alert levels that require immediate action and maintenance levels that require evaluation and planning for corrective action within a specified timeframe.

Structural Evaluation

Structural pavement evaluation per AC 150/5320-6G uses Falling Weight Deflectometer (FWD) testing to assess the structural capacity of existing pavements. The FWD applies a dynamic load (typically 12,000 to 60,000 lbs simulating aircraft gear loads) and measures the resulting pavement surface deflections using geophones or seismometers. The measured deflection data is analyzed using back-calculation procedures to determine the in-situ modulus of each pavement layer and the effective subgrade modulus.

The AC specifies that FWD testing for pavement evaluation should be conducted at 200-foot (60-meter) intervals along the pavement centerline and at multiple lateral positions to capture the full range of structural variation. The back-calculated layer moduli are used as inputs to FAARFIELD for overlay thickness design and remaining life estimation.

Inspection Frequency Requirements

The ACs establish the following typical inspection frequencies:

Accessing and Using FAA Advisory Circulars

All FAA Advisory Circulars are available for free download from the FAA website. The primary access point is the Airports Advisory Circulars page at www.faa.gov/airports/resources/advisory_circulars/ , which provides searchable access to all active, cancelled, and draft ACs in the Airports (150) series.

Search and Retrieval

The FAA AC database supports searching by:

• Document Number — e.g., “150/5320-6” returns all versions of that AC
• Title — keyword search in the AC title
• Description — keyword search in the AC description text
• Status — filter by Active, Cancelled, or Inactive
• Date — search by issue date range
• Subject/Browse — browse by topic area (Design, Construction, Maintenance, etc.)

Each AC listing provides the complete document detail including document number, title, status, issue date, initiating office, and a PDF download link. Draft ACs are also published for public comment with specific comment deadlines and submission instructions.

Status Tracking

The FAA maintains a “New and Revised FAA Airports Series 150 Advisory Circulars” page that tracks recently issued, revised, and draft ACs. This page includes:

• New ACs issued within the past 12 months
• Revised ACs with summary of changes
• Draft ACs open for public comment
• Recently cancelled ACs with superseding documents identified

Engineers and airport operators should subscribe to this page or check it regularly to ensure they are using the most current versions of applicable ACs.

Mandatory vs. Recommended Use

The Application section of each AC defines whether its provisions are mandatory or recommended. The standard language states:

“The FAA recommends the guidelines and specifications in this AC for [specific application]. Use of this AC is mandatory for all projects funded with Federal grant monies through the Airport Improvement Program (AIP) or with revenue from the Passenger Facility Charge (PFC) Program.”

This means that for AIP and PFC funded projects, compliance with the AC’s provisions is a contractual requirement enforceable through the grant agreement. For non-federally funded projects, the AC provides recommended best practices that the FAA encourages but does not mandate.

For Part 139 certificated airports, certain AC requirements become regulatory requirements because 14 CFR Part 139.305 (Pavement Areas) requires that airport operators maintain paved areas in a condition that meets the standards specified in FAA ACs, including friction requirements and pavement condition standards.

Using ACs in Practice

Airport pavement professionals use ACs in the following ways:

• Design engineers use AC 150/5320-6G and FAARFIELD for pavement structural design, and AC 150/5370-10H for developing construction specifications
• Construction inspectors use AC 150/5370-10H for acceptance testing, material verification, and construction quality control
• Pavement inspectors use AC 150/5380-7B and ASTM D5340 for PCI surveys, AC 150/5320-12C for friction testing, and AC 150/5320-6G for FWD structural evaluation
• Airport operators use AC 150/5380-7B for pavement management program development, AC 150/5380-6C for maintenance planning, and AC 150/5335-5C for PCN reporting
• Consultants use all applicable ACs to ensure their work products comply with FAA standards and are eligible for federal funding

The FAA also provides training materials and webinar recordings on various AC topics through the FAA Airport Technology Research and Development Branch website. These resources help professionals stay current with AC updates and understand the technical basis for AC requirements.

Recent Updates and Emerging Developments

The FAA continuously revises its Advisory Circulars to incorporate new research, technology advances, and industry best practices. Recent and upcoming developments include:

AC 150/5320-6G (June 2021) — This major update to the pavement design AC included:

• Updated FAARFIELD software with improved structural models
• Revised traffic analysis procedures for mixed traffic
• Updated material characterization guidance including dynamic modulus (E*) testing
• Enhanced guidance on evaluating existing pavements for overlay design
• Updated guidance on design for aircraft with high tire pressures

AC 150/5370-10H and Change Notifications — The FAA continues to issue change notifications to update individual specification items. Recent changes have addressed:

• Updated P-401 asphalt specification requirements including loaded wheel testing
• Revised P-501 concrete pavement jointing and dowel bar requirements
• Updated material testing protocols
• Enhanced QC/QA provisions

Draft AC 150/5320-12D — The draft update to the skid resistance AC will:

• Update FAA-approved CFME manufacturer information
• Revise friction threshold values based on recent research
• Provide enhanced guidance on grooving and porous friction course (PFC) construction
• Update friction data analysis and trend monitoring procedures
• Incorporate guidance on surface texture measurement

FAARFIELD 2.0+ Development — The FAA continues to develop the FAARFIELD software with enhanced capabilities for structural evaluation, remaining life analysis, and life-cycle cost optimization. These software updates are coordinated with AC 150/5320-6G revisions to ensure consistency between the computational tools and the design guidance.

Pavement Management Integration — The FAA is working to strengthen the integration between pavement management (AC 150/5380-7B) and pavement design (AC 150/5320-6G) by developing standardized data exchange formats and analysis procedures that allow seamless transfer of pavement condition data into structural evaluation and design processes.

Airport Pavement Inspection Technology — The FAA is exploring the integration of advanced inspection technologies including automated distress detection using deep learning and computer vision systems, LiDAR for pavement surface characterization, and ground penetrating radar (GPR) for subsurface evaluation. These technologies, once validated, may be incorporated into future AC revisions to provide alternative inspection methods that complement traditional visual PCI surveys and FWD testing.

Conclusion

FAA Advisory Circulars form the comprehensive technical backbone of airport pavement engineering in the United States. From initial design through AC 150/5320-6G and construction through AC 150/5370-10H, to management through AC 150/5380-7B, maintenance through AC 150/5380-6C, friction evaluation through AC 150/5320-12C, and strength reporting through AC 150/5335-5C, these documents establish the complete lifecycle framework for airport pavements.

The AC system’s strength lies in its integration — each AC addresses a specific phase of the pavement lifecycle while maintaining consistency with the others through cross-references and shared technical foundations. The FAARFIELD and COMFAA software tools provide the analytical engine that connects design thresholds, evaluation results, and strength reporting requirements into a unified technical framework.

For airport pavement inspectors, understanding the AC framework is essential because inspection criteria are not defined in a single document but are distributed across multiple ACs that together define what constitutes compliant, safe, and cost-effective pavement infrastructure. The PCI methodology, friction thresholds, structural evaluation protocols, and condition prediction models that form the basis of pavement inspection and management are all defined within specific ACs and must be applied within the context of the complete AC system.

The FAA’s commitment to continuous improvement ensures that ACs evolve to reflect advances in materials science, construction technology, and inspection methodology. Airport pavement professionals should maintain awareness of AC updates, participate in public comment periods for draft ACs, and ensure their practices remain aligned with current FAA standards to maintain regulatory compliance and optimize the performance of their pavement infrastructure.