U.S. airlines’ March systemwide (domestic and international) scheduled service passenger enplanements rose 0.2 percent from February, rising to 73.1 million to reach a new all-time seasonally-adjusted high, rising for the second consecutive month.

One month: February 2018 to March 2018 enplanements on domestic flights rose 0.1 percent while enplanements on international flights to and from the U.S. rose 0.9 percent for a 0.2 percent systemwide increase.

One Year: March 2017 to March 2018 domestic enplanements rose 4.5 percent while enplanements on U.S. airlines’ international flights to and from the U.S. rose 5.4 percent for a 4.6 percent systemwide increase.

Three Years: March 2015 to March 2018 domestic enplanements flights rose 11.6 percent while enplanements on U.S. airlines’ international flights to and from the U.S. rose 10.3 percent for an 11.4 percent systemwide increase.

Unadjusted: Systemwide, domestic and international enplanements all reached highs for the month of March.

Seasonally-Adjusted Trends

New seasonally-adjusted all - time highs

Passenger enplanements: Systemwide, domestic and international passenger enplanements reached new seasonally-adjusted all-time highs.

Revenue passenger-miles: Systemwide, domestic and international revenue passenger miles (RPMs) reached new seasonally-adjusted all-time highs.

Available seat-miles: Systemwide domestic and international available seat-miles (ASMs) reached new seasonally-adjusted all-time highs.

Load Factor

Systemwide load factor (84.2 percent) was down 0.6 points from the all-time seasonally-adjusted high (84.8 percent) reached in October 2015. Domestic and international load factor both declined.

Load factor is a measure of the use of aircraft capacity that compares the system use, measured in RPMs as a proportion of system capacity, measured ASMs.

The load factor rose from February (83.9 percent) to March (84.3 percent) because passenger travel grew faster (0.8 percent increase in RPMs) than system capacity (0.4 percent increase in ASMs).

Seasonally-adjusted trends are for the time period January 2000 to present. Additional data, including domestic and international numbers, can be found on the seasonally-adjusted data  page.

New March unadjusted all-time highs

Passenger enplanements: Systemwide, domestic and international passenger enplanements reached new highs for the month of March.

One month: February 2018 to March 2018: domestic enplanements rose 23.2 percent and enplanements on U.S. airlines’ international flights to and from the U.S. rose 26.3 percent for a 23.6 percent systemwide increase.

One year: March 2017 to March 2018, domestic enplanements rose 4.2 percent while international enplanements rose 7.2 percent for a 4.6 systemwide increase.

Three years: March 2015 to March 2018, domestic enplanements rose 11.9 percent while international enplanements rose 11.6 percent for a 11.9 systemwide increase.

Revenue passenger-miles: Systemwide, domestic and international revenue passenger miles (RPMs) reached new highs for the month of March.

Available seat-miles: Systemwide, domestic and international available seat-miles (ASMs) reached new highs for the month of March.

Load Factor:

Systemwide load factor (85.0 percent) reached an all-time March high, up 0.7 points from the previous high (84.3 percent) reached in 2013. Domestic load factor (86.1 percent) reached an all-time March high, up 0.3 points from the previous high (85.8 percent) reached in 2015. International load factor (82.4 percent) was down 0.1 points from the all-time March high (82.5 percent) reached in 2013.

The load factor rose from March 2017 (83.5 percent) to March 2018 (85.0 percent) because passenger travel grew faster (5.9 percent increase in RPMs) than system capacity (4.1 percent increase in ASMs).

Unadjusted trends are for the time period January 1996 to present. Data are available at Customize Table and can be downloaded from the seasonally-adjusted data  page.

Explanation of seasonal adjustment

When the primary purpose is to examine monthly shifts in transportation services output and analyze short-term trends, the variation introduced by normal seasonal changes must be removed from the data. Transportation is highly seasonal, and without adjustment, the data do not give an accurate picture of underlying changes in aviation, passenger travel.

Seasonal adjustment of the data removes the seasonal events that follow a regular seasonal pattern. Changes that are not due to seasonality, such as a change in air travel resulting from economic conditions become more readily apparent.

The aviation data are seasonally adjusted for the effects of trading day, moving holidays, and data outliers.

See Seasonal Adjustment for methodology and additional explanation.

Reporting Notes

Data are compiled from monthly reports filed with BTS by commercial U.S. air carriers detailing operations, passenger traffic and freight traffic. This release includes data received by BTS from 79 U.S. carriers as of June 5 for U.S. carrier scheduled civilian operations.

For additional scheduled service numbers for U.S. and foreign airlines, by airline and by airport, see Passengers, Flights, Revenue Passenger-Miles, Available Seat-Miles and Load Factor. To create a customized table for passengers, flights, RPMs, ASMs and other data, including non-scheduled service, go to https://www.transtats.bts.gov/TRAFFIC/

BTS has scheduled July 13 for the release of April traffic data. None of the data are from samples so measures of statistical significance do not apply.