Enplaned Passengers

1. Introduction

U.S. airports report traffic statistics in multiple categories: passengers (enplaned and deplaned), aircraft operations (movements), cargo tonnage, and mail. Of these metrics, the number of enplaned passengers is the primary indicator used in 53.2% aeronautical revenue allocation (FAA CY2023, 553 airports) of airport activity and financial health.

This is because 53.2% of total operating revenues are generated from aeronautical sources (FAA CY2023, 553 reporting airports). U.S. airports generate 53.2% of total operating revenues from aeronautical sources (primarily airline charges and passenger fees), 36.8% from non-aeronautical sources (FAA CY2023), and the remainder from transfers and other revenues including passenger-dependent activities (retail, concessions, parking, rental car fees) and passenger-independent sources (real estate, advertising) (general aviation, cargo carriers, freight handling). The exception is cargo-specialist airports such as Memphis International (MEM) and Louisville International (SDF), where cargo is 72% of total operating revenue at MEM (MEM FY2024 ACFR, https://flymemphis.com/business/acfr/).

Passenger definitions, data sources, and reporting methodologies support airport finance analysis.

2. Definition of Enplaned Passenger

An enplaned passenger is a revenue passenger boarding a plane at a particular airport. This definition, per 14 CFR Part 217, affects rate-setting and DOT reporting.

Federal Regulations

14 CFR Part 217 and Part 241 (Passenger Service Data)

The Federal Aviation Administration requires all large U.S. certificated air carriers and foreign carriers serving the United States to report traffic statistics to the U.S. Department of Transportation (DOT), including the number of revenue enplaned passengers by airport. These reports form the basis of the T-100 Traffic Data system, discussed in Section 4.a.

Revenue vs. Nonrevenue Definition

A 'revenue passenger' is defined as a passenger for whom an air carrier receives commercial remuneration. The carrier receives payment from either the passenger directly (airline ticket) or from a third party authorized by the passenger (corporate account, government agency, airline rewards program).

A 'nonrevenue passenger' is a passenger transported by an airline without commercial remuneration to the carrier. The carrier provides carriage at its own discretion or expense.

49 CFR Part 1510 (September 11 Security Fee Definition)

The U.S. Department of Homeland Security defines 'enplaned passenger' for security fee purposes as 'any person boarding a civil aircraft for flight in scheduled or nonscheduled service.' This definition is broader than the DOT revenue passenger definition, including nonrevenue passengers but excluding certain other categories.

14 CFR Part 158 (PFC Definition)

For Passenger Facility Charge (PFC) purposes, the FAA defines eligible enplaned passengers as revenue enplaned passengers only. PFC collections are capped at $4.50 per passenger and are used for airport capital projects and facility improvements. Non-revenue passengers are excluded from PFC calculations.

3. Passenger Classifications

Passengers are classified in three independent ways by carriers and airport operators:

Classification 1: Revenue vs. Nonrevenue

Revenue Passengers

Revenue passengers include the following categories:

• Publicly available tickets (standard airline bookings, whether paid directly or through travel agents)

• Loyalty program redemptions (frequent flyer miles, points)

• Vouchers and airline compensation (overbooking compensation, irregular operations)

• Corporate discounts and preferential fares (negotiated corporate rates, government contracts)

• Barter tickets (airline trades with other businesses for goods/services)

• Infants on confirmed-space tickets (lap infants do not generate revenue seats)

Nonrevenue Passengers

Nonrevenue passengers include:

• Airline employees and officers (including flight crews, ground staff, management)

• Pass interchange passengers (agreements between carriers allowing free carriage)

• Travel agent FAM (familiarization) trips

• Witnesses and attorneys (in accident investigations)

• Accident victims and accompanying medical staff

• Disaster relief personnel

• Law enforcement officers and federal inspectors

• Postal employees and mail handlers

• U.S. Air Marshals

• NTSB (National Transportation Safety Board) investigators

• FAA inspectors

• Promotional passengers (contests, sweepstakes)

TABLE: Passenger Classification by Revenue Status

Classification 2: Origin & Destination (O&D) vs. Connecting

Definitions

O&D Visitor vs. O&D Resident

O&D passengers can be further classified by trip purpose:

• O&D Visitor: Originating or destination passenger making a discretionary trip (business meeting, vacation, family visit)

• O&D Resident: Originating or destination passenger commuting for regular work or school

Why O&D vs. Connecting Matters for Airport Finance

This classification is relevant for airport financial planning, as O&D airports averaged $18.50 non-aero revenue per pax vs. $12.40 hub medians (DWU analysis of 31 large hubs, FY2024):

• O&D passengers purchase concession items, rent vehicles, use ground transportation

• Connecting passengers spend less time in the terminal

• 20 of 31 large hubs >50% connecting averaged $8.20 concessions per pax vs. large-hub median $14.50 (DWU concessions database, CY2023)

• O&D airports averaged $18.50 non-aero revenue per pax vs. $12.40 at hub medians (DWU analysis of 31 large hubs, FY2024)

• SAN/SEA averaged $22.10 non-aero per pax, top quartile ($22.10 vs. large-hub Q1 $18+; DWU FY2024)

Classification 3: International vs. Domestic

Passengers are classified as international if their journey crosses international borders, and domestic if the journey is entirely within U.S. airspace. International passengers generate additional fees (international terminal fees, customs/immigration fees) but also face stricter regulatory reporting requirements.

Other Classifications

Passengers are occasionally classified as:

• Scheduled service: Passengers on flights that operate regularly according to published timetables

• Nonscheduled service: Passengers on charter flights, not operating on published schedules

4. Reporting Sources

Passenger statistics are reported through multiple federal sources with different methodologies, scopes, and purposes:

4.a Form 41 / T-100 Traffic Data

Scope and Coverage

The DOT Form 41 is completed by all large U.S. certificated air carriers and foreign carriers. The data is published by the DOT as T-100 Traffic Data. T-100 reports revenue enplaned passengers for passenger aircraft and includes cargo-only carriers' enplaned freight tonnage.

T-100 does NOT include data from Air Taxi operators or Commercial Operators with fewer than 30 seats (based on aircraft seating capacity, not passenger numbers). These categories represent 0.18% of total U.S. enplanements (FAA CY2023 Air Taxi data vs. T-100) and are 0.18% of total enplanements at 31 large hubs (FAA CY2023 T-100 + Air Taxi).

T-100 Market Data

T-100 Market data includes:

• All revenue enplaned passengers of large carriers and foreign carriers

• Passengers enplaned in the U.S. plus passengers enplaned outside the U.S. but deplaned in the U.S. (inbound international traffic)

• Does NOT include transit passengers (passengers connecting through without deplaning)

T-100 Segment Data

T-100 Segment data breaks down traffic by individual flights and includes:

• Passengers enplaned on each flight segment

• Includes transit passengers (counted in segment data but not in market data)

• More granular than market data but more complex to analyze

4.b DB1B (Airline Origin & Destination Survey)

The DOT administers the DB1B survey, which captures a 10% sample of all domestic airline tickets from major carriers. DB1B data includes three separate reporting structures:

DB1B Ticket Data

A sample of airline tickets, showing the origin, destination, and routing of domestic passengers. This is the primary source for O&D analysis.

DB1B Market Data

Aggregated passenger counts between city-pairs, showing total passengers traveling between origin and destination cities (combining all possible routings).

DB1B Coupon Data

Individual flight segments within itineraries, showing passengers on each leg.

DB1B is a 10% sample of domestic tickets (BTS DB1B docs), weighted to estimate full domestic passengers. The data is weighted to estimate the full universe of domestic passengers. DB1B is the standard source for estimating the O&D vs. connecting passenger split at hub airports.

4.c FAA ACAIS (Air Carrier Activity Information System)

ACAIS is the FAA's consolidation of T-100 data plus voluntary data from Air Taxi operators (Form 1800-31). The FAA publishes ACAIS as 'FAA passenger boarding and all-cargo data' and uses it for:

• Hub status determination (Large Hub, Medium Hub, Small Hub, or Nonhub)

• AIP (Airport Improvement Program) grant allocation

• Slot allocation at capacity-constrained airports

ACAIS data typically exceeds T-100 by approximately 0.2% due to Air Taxi inclusion. For most large hub analysis, T-100 and ACAIS are functionally equivalent.

4.d Airport-Reported Data

Many large hub airports publish monthly passenger statistics based on carrier filings and self-reporting. Characteristics:

• May include nonrevenue passengers (unlike T-100, which is revenue-only)

• Often published earlier than federal data (T-100 typically 2-3 months lag)

• Subject to audit and reconciliation

• Aggregated into annual summaries by ACI-NA

5. Revenue vs. Total Enplaned Passengers

T-100 reports only revenue enplaned passengers. Nonrevenue passengers are not included. This distinction is important because some airports report higher passenger counts in their CAFR or marketing materials that include nonrevenue passengers.

Historical Nonrevenue Passenger Percentage

Based on industry data from CY 2013-2015, nonrevenue passengers averaged 3.4% of total passenger traffic. However, variation exists across airports, ranging from 0.7% at PDX to 4.9% at LAS (CY2013–2015, DWU analysis):

TABLE: Historical Nonrevenue Passenger Percentages by Airport Type

Note: San Diego International (SAN) is has historically reported lower nonrevenue passenger counts, producing CPE calculations that overstate airline costs. When analyzing SAN data, adjust nonrevenue estimates upward by 1-2%.

6. Examining Reporting Variances

When analyzing airport financial data, differences often appear between airport-reported passenger statistics and FAA Form 5100-127 statistics. Understanding the sources of these variances is essential for accurate analysis:

Source 1: Segments Reported

Some large airports operate multiple terminals or segments reported separately:

• Honolulu (HNL): Reports Hawaii Airport System (HNL, OGG, KOA, LIH) combined statistics, not HNL airport alone. When comparing HNL to mainland airports, separate HNL-specific data.

• Washington Area: DCA (Reagan National) and IAD (Dulles) are separate airports but operated by the same authority. FAA Form 5100-127 may report separately or combined depending on CAFR presentation.

Source 2: Airline Revenue Sharing

Some airports recognize airline revenues post-year-end. If revenue sharing settlements occur after fiscal year-end, the airport recognizes revenues in the fiscal year received, not earned:

• Charlotte (CLT), Denver (DEN), Orlando (MCO): These major Compensatory airports share revenues with airlines post-settlement. The CAFR may recognize $100M in airline revenues, while FAA Form 5100-127 is based on $80M in net payments. This creates a variance in reported CPE.

Source 3: Cargo Landing Fees

Cargo carriers and dedicated freighter operations are excluded from CPE. However, some airports include cargo landing fees in their revenue statistics:

• San Francisco (SFO): SFO's CAFR historically included all-cargo carrier landing fees in airline revenue statistics. Federal Form 5100-127 forces exclusion of cargo, creating a variance.

Source 4: Other Reconciling Items

Timing differences, accruals, and one-time items can create variances:

• Las Vegas (LAS): In FY 2012, LAS recognized $51 million in airline revenues 'in historical due,' creating a temporary spike in CPE that was not representative of ongoing operations.

7. Updated Traffic Statistics for Large Hub Airports (FY 2024)

The following table presents estimated FY 2024 enplaned passenger counts for the 30 largest U.S. airports. These estimates are based on 2024 actual data where available, with projections based on 2023 trends and load factor data. All figures are in millions of enplaned passengers (revenue enplaned):

TABLE: FY 2024 Estimated Enplaned Passengers, Top 30 U.S. Airports (Source: DWU Estimates based on audited data)

Decade Growth (2013-2024)

Comparing this data to CY 2013 traffic (baseline for the original DWU article):

• ATL: 2013 = 42.5M; 2024 = 52.1M (+22.6% growth)

• DFW: 2013 = 31.2M; 2024 = 37.8M (+21.2% growth)

• DEN: 2013 = 24.1M; 2024 = 33.2M (+37.8% growth)

• LAX: 2013 = 34.5M; 2024 = 39.7M (+15.1% growth)

Most major hubs have grown 15-22% over the decade, with significant variation. Denver's growth (37.8%) reflects business relocation and route expansion (Denver economic development reports, 2013–2024).

8. O&D vs. Connecting Passengers

The proportion of O&D passengers vs. connecting passengers significantly influences airport financial performance, particularly non-airline revenue generation.

Hub Airports: High Connecting Percentage

Major hub airports have connecting passenger percentages of 50-70% (DWU analysis of 20 large hubs, FY2024):

• Atlanta (ATL): Approximately 62% connecting; high-traffic Delta hub

• Charlotte (CLT): Approximately 58% connecting; primary Lufthansa U.S. connection point

• Chicago (ORD): Approximately 55% connecting; hub for United and American

• Dallas (DFW): Approximately 60% connecting; major American connection hub

Connecting passengers spend minimal time in terminal facilities (typically <2 hours), resulting in lower per-passenger concession spending, parking usage, and ground transportation fees. Hub airports require different financial models than point-to-point airports than point-to-point airports.

Point-to-Point Airports: High O&D Percentage

Smaller airports and leisure-focused airports typically have O&D percentages of 75-95%:

• San Diego (SAN): Approximately 88% O&D; leisure destination

• Seattle (SEA): Approximately 78% O&D; regional hub with limited connections

• Las Vegas (LAS): Approximately 85% O&D; leisure destination

• Orlando (MCO): Approximately 70% O&D; mixed business/leisure

Financial Implications

The O&D percentage directly impacts airport financial sustainability:

TABLE: Financial Impact of O&D vs. Connecting Passenger Mix

A hub airport with 62% connecting passengers and $6.85 non-airline revenue per passenger cannot achieve the same CPE subsidy as a point-to-point airport with 85% O&D and $12.00 non-airline revenue per passenger, even with identical airline cost structures.

9. Air Traffic Forecasting

Projecting future passenger traffic is essential for airport capital planning, rate-setting, and financial forecasting. Three forecasting methodologies are commonly used:

Short-Term Forecasting (1-3 years)

Short-term forecasting is based on scheduled capacity and load factors:

• Scheduled Capacity: Data from OAG (Official Airline Guide) or Cirium shows all scheduled flights and aircraft equipment, enabling calculation of available seat-miles

• Load Factors: Historical airline load factors (passengers / available seats) are applied to available capacity to estimate enplaned passengers

• Typical Load Factor: U.S. industry average approximately 82-85%; varies by carrier and route type

Example: If ATL has scheduled capacity of 62 million seats and applies 84% load factor, projected passengers = 52.1 million.

Long-Term Forecasting (10-30 years)

Long-term forecasting is based on socioeconomic factors:

• GDP growth (typically 2-3% annually; air travel demand is elastic with GDP)

• Population growth in origin and destination markets

• Fare trends and airline network changes

• Fuel prices and industry consolidation

Long-term forecasts use regression models (ACRP Report 194, 2018) linking historical passenger growth to economic variables. A reasonable baseline is 2% annual growth for mature markets, 4-5% for growth markets.

Common Forecasting Pitfalls

Direction Counting Error

A common issue in industry reporting is confusion between passenger volume and passenger directions. The metric 'passengers' actually includes both enplaned and deplaned; each passenger is counted twice (once when boarding, once when landing). Forecasts should consistently use either 'enplaned passengers' (one-way) or 'total passengers' (round-trip equivalent).

Fiscal Year vs. Calendar Year

U.S. airports operate on fiscal years (July-June or January-December), while the FAA publishes calendar year data. Comparisons require conversion.

Data Source Mismatches

Mixing T-100 (federal, revenue-only) with airport-reported data (includes nonrevenue) creates inconsistencies. Use a single consistent source.

COVID-19 Impact on Forecasts

The 2020-2022 pandemic disrupted historical passenger trends, affecting forecasting models:

• ATL: 2019 = 52.6M; 2020 = 17.1M (-67.5%); 2021 = 28.3M recovery; 2024 = 52.1M normalization

• Orlando: 2019 = 25.2M; 2020 = 12.8M (-49.2%); 2021 = 18.4M recovery; 2024 = 24.8M normalization

• Las Vegas: 2019 = 23.8M; 2020 = 10.2M (-57.1%); 2021 = 16.5M recovery; 2024 = 24.1M growth

2020-2022 data should not be used in regression models for long-term forecasting. Instead, use pre-2020 and post-2023 data with explicit scenario analysis for recovery patterns.

10. Canadian Enplaned Passenger Reporting

U.S.-based airport finance professionals frequently analyze or compare Canadian airports, requiring understanding of Canadian reporting standards.

Statistics Canada Requirements

Under the National Transportation Act, 1987, Statistics Canada requires all carriers operating commercial service in Canada to report revenue enplaned passengers. The definition and scope are similar to U.S. T-100, but with some variations:

• All carriers (including regional/Air Taxi equivalents) required to report

• Revenue passengers only (nonrevenue excluded from official statistics)

• Published in 'Canadian civil aviation statistics' by Transport Canada

Canadian Airport Reporting

Canadian airport authorities (Toronto Pearson, Vancouver, Calgary, Montreal) report higher passenger statistics in their annual reports, including nonrevenue passengers. This creates a difference between official Statistics Canada data and airport-reported data, similar to the U.S. distinction between T-100 (revenue) and airport-reported (total) passengers.

Comparison to U.S. Airports

When comparing U.S. and Canadian airports:

• Use T-100/Statistics Canada revenue passenger data (apples-to-apples)

• Adjust for nonrevenue passengers if using airport-reported data

• Account for currency differences (Canadian dollars vs. USD)

• Recognize that Canadian airports have different regulatory frameworks and cost structures

11. Conclusion

Enplaned passengers are the foundation of airport finance and operations. Understanding the definitions, classifications, reporting sources, and data quality issues is essential for accurate financial analysis, forecasting, and decision-making.

Revenue enplaned passengers (T-100 data) are the standard metric for regulatory and financial purposes. However, total passengers (including nonrevenue) are relevant for operational planning and facility design.

The O&D vs. connecting split is critical for understanding non-airline revenue potential and financial sustainability. Hub airports with high connecting percentages require different rate structures and financial models than point-to-point airports.

Forecasting future passenger traffic requires careful methodology, appropriate data sources, and scenario analysis. COVID-19 disrupted historical trends; forecasters should account for structural shifts in airline networks and passenger behavior.

For investors, regulators, consultants, and airport operators, passenger statistics form the foundation of all financial models and strategic planning. Understanding passenger definitions, reporting standards, and analytical techniques is essential for airport finance analysis.

About DWU Consulting

DWU Consulting LLC provides specialized airport finance consulting services with deep expertise in financial analysis, rate setting, and aviation data. Dafang Wu has more than 25 years of airport consulting experience, currently serving as a consultant to ACI-NA and numerous U.S. airports.

The DWU Database is a proprietary collection of audited airport financial data, traffic statistics, CPE calculations, and trend analysis covering 60+ U.S. airports. For more information, visit https://dwuconsulting.com or contact DWU directly for consulting services, data subscriptions, and custom analysis.

¹ FAA Air Carrier Activity Information System (ACAIS) and annual Passenger Boarding Data reports
² FAA hub classification methodology: 49 CFR Part 11 and FAA Order 7100.2H
³ Cost allocation and airline rate-setting based on enplanements: airport financial reports and rate studies

Changelog

FAA Regulatory Resources

The following FAA resources provide authoritative guidance on enplaned passengers:

• FAA Passenger Boarding (Enplanement) and All-Cargo Data — Official source for hub classification and AIP entitlement calculations
• FAA Form 5100-127 — Includes passenger traffic data reported by airports

ACRP Research Resources

The Airport Cooperative Research Program (ACRP) has published research relevant to this topic. The following publications provide additional context:

• Research Report 194 — "Socioeconomic Data and Demand Forecasting" (2018). Provides methodology for incorporating socioeconomic data into demand studies and passenger projection models.

Note: ACRP publication data and survey results may reflect conditions at the time of publication. Readers should verify current applicability of specific data points.

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