The airlines also set all-time semi-annual highs for systemwide, domestic and international revenue passenger miles (RPMs) and available seat-miles (ASMs).

The record number of airline passengers in the first six months of 2017 resulted in fewer systemwide empty seats because growth in international passenger travel outpaced growth in international capacity, offsetting a domestic capacity growth rate that slightly exceeded passenger travel growth. Load factor – the measure of the use of airline capacity – rose from 2016 but remained below peak levels of previous years (Tables A, B, C).

The six-month load factor rose from 2016 (82.7) to 2017 (82.9) because passenger travel (3.1 percent increase in RPMs) grew faster than system capacity (2.8 percent increase in ASMs) (Table A).

Semi-Annual Trends:

Systemwide passenger enplanements (414.4 million) reached an all-time January through June high, up 2.8 percent from the previous high (403.1 million) reached in 2016 (Table A, Figure 1). Domestic passenger enplanements (360.9 million) reached an all-time semi-annual high, up 2.7 percent from the previous high (351.6 million) reached in 2016 (Table B). International passenger enplanements (53.5 million) reached an all-time semi-annual high, up 3.8 percent from the previous high (51.5 million) reached in 2016 (Table C).

Systemwide RPMs (468.9 billion) reached an all-time January through June high, up 3.1 percent from the previous high (454.9 billion) reached in 2016 (Table A). Domestic RPMs (332.8 billion) reached an all-time semi-annual high, up 3.3 percent from the previous high (322.3 billion) reached in 2016 (Table B). International RPMs (136.0 billion) reached an all-time semi-annual high, up 2.5 percent from the previous high (132.7 billion) reached in 2016 (Table C).

Systemwide ASMs (565.8 billion) reached an all-time January through June high, up 2.8 percent from the previous high (550.2 billion) reached in 2016 (Table A). Domestic ASMs (395.6 billion) reached an all-time semi-annual high, up 3.4 percent from the previous high (382.7 billion) reached in 2016 (Table B). International ASMs (170.2 billion) reached an all-time semi-annual high, up 1.6 percent from the previous high (167.5 billion) reached in 2016 (Table C).

Systemwide load factor (82.9) was down 0.3 points from the all-time January through June high (83.2) reached in 2014 (Table A). Domestic load factor (84.1) was down 0.5 points from the all-time semi-annual high (84.6) reached in 2014 (Table B). International load factor (79.9) was down 1.2 points from the all-time semi-annual high (81.2) reached in 2013 (Table C). 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 in ASMs.

June 2017 U.S. Airline Scheduled Service Numbers

Trends (Percent changes based on unrounded numbers)

Seasonally-adjusted

Systemwide passenger enplanements (70.9 million) reached a new seasonally-adjusted all-time high, up less than one-tenth of 1 percent from the previous high in May 2017 (70.8 million) (Table 1, Figure 2). Domestic passenger enplanements (61.7 million) were down 0.04 percent from the all-time seasonally-adjusted high (61.74 million) reached in May 2017 (Table 2). International passenger enplanements (9.14 million) reached a new seasonally-adjusted all-time high, up 0.2 percent from the previous high in April 2017 (9.11 million) (Table 3).           

Systemwide revenue passenger miles (RPMs) (80.9 billion) reached a new seasonally-adjusted all-time high, up 0.5 percent from the previous high in May 2017 (80.5 billion) (Table 4). Domestic RPMs (57.1 billion) reached a new seasonally-adjusted all-time high, up 0.3 percent from the previous high in May 2017 (56.9 billion) (Table 5). International RPMs (23.8 billion) were down less than one-tenth of 1.0 percent from the all-time seasonally-adjusted high (23.78 billion) reached in April 2017 (Table 6).

Systemwide available seat-miles (ASMs) (96.9 billion) reached a new seasonally-adjusted all-time high, up 0.9 percent from the previous high in May 2017 (96.1 billion) (Table 7). Domestic ASMs (67.8 billion) reached a new seasonally-adjusted all-time high, up 1.1 percent from the previous high in May 2017 (67.1 billion) (Table 8). International ASMs (29.2 billion) reached a new seasonally-adjusted all-time high, up 0.4 percent from the previous high in May 2017 (29.1 billion) (Table 9).

Systemwide load factor (83.5) was down 1.2 points from the all-time seasonally-adjusted high (84.7) reached in October 2015 (Table 10). Domestic load factor (84.3) was down 1.6 points from the all-time seasonally-adjusted high (85.9) reached in October 2015 (Table 11). International load factor (81.6) was down 1.4 points from the all-time seasonally-adjusted high (83.0) reached in March 2013 (Table 12).

The seasonally-adjusted load factor declined from May (83.8) to June (83.5) despite growth in passenger travel (0.5 percent increase in RPMs) because system capacity grew more (0.9 percent increase in ASMs) (Tables 4, 7).

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.

Unadjusted

Systemwide passenger enplanements (76.94 million) reached an all-time high for any month, up less than one-tenth of 1.0 percent (0.08 percent) from the previous high (76.88 million) reached in July 2016 and up 3.3 percent from the previous June high (74.5 million) reached in 2016 (Table 13, Figure 3). Domestic passenger enplanements (66.7 million) reached an all-time high for any month, up 0.8 percent from the previous high (66.1 million) reached in July 2016 and up 3.0 percent from the previous June high (64.8 million) reached in 2016 (Table 14). International passenger enplanements (10.3 million) reached an all-time June high, up 5.3 percent from the previous high (9.7 million) reached in 2016 (Table 15).

Systemwide RPMs (89.7 billion) reached an all-time June high, up 3.6 percent from the previous high (86.5 billion) reached in 2016 (Table 16). Domestic RPMs (62.5 billion) reached an all-time high for any month, up 0.2 percent from the previous high (62.3 billion) reached in July 2016 and up 3.6 percent from the previous June high (60.3 billion) reached in 2016 (Table 17). International RPMs (27.2 billion) reached an all-time June high, up 3.7 percent from the previous high (26.2 billion) reached in 2016 (Table 18).

Systemwide ASMs (103.7 billion) reached an all-time June high, up 3.9 percent from the previous high (99.9 billion) reached in 2016 (Table 19). Domestic ASMs (71.7 billion) reached an all-time high for any month, up 0.2 percent from the previous high (71.5 billion) reached in July 2016 and up 4.2 percent from the previous high (68.8 billion) reached in 2016 (Table 20). International ASMs (32.0 billion) reached an all-time June high, up 3.2 percent from the previous high (31.1 billion) reached in 2016 (Table 21).

Systemwide load factor (86.4) was down 0.5 points from the all-time June high (87.0) reached in 2013 (Table 22). Domestic load factor (87.1) was down 0.5 points from the all-time June high (87.6) reached in 2016 (Table 23). International load factor (84.9) was down 2.0 points from the all-time June high (86.9) reached in 2013 (Table 24).

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 83 carriers as of Sept. 6 for U.S. carrier scheduled civilian operations.

Go to http://www.transtats.bts.gov/releaseinfo.asp for the complete list of reporting and non-reporting carriers. U.S. carriers’ foreign point-to-point flights are included in system and international totals. 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/

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.

Traffic numbers are available on the BTS website at TranStats, the Intermodal Transportation Database, at http://transtats.bts.gov.  Click on “Aviation.”  For systemwide passengers, RPMs and ASMs by carrier through June, click on “Air Carrier Summary Data (Form 41 and 298C Summary Data),” and then click on “Schedule T-1.” Use crosstabs to find scheduled service.

For domestic numbers through June and international numbers through March by origin as well as by carrier, click on “Aviation,” then click on “Air Carrier Statistics (Form 41 Traffic).”  Click on “T-100 Market” for system passenger numbers, “T-100 Domestic Market” for domestic or “T-100 International Market” for international.  For flights, stage length and trip length, use the appropriate T-100 Segment database. Use crosstabs to find scheduled service.

International totals in this press release consist of all U.S. carrier operations to and from the U.S. and from one foreign point to another foreign point. TranStats T-100 systemwide and international totals do not include U.S. carriers’ foreign point-to-point flights. For June, U.S. carriers reported 50,970 foreign point-to-point passengers. For January through June, U.S. carriers reported 353,924 foreign point-to-point passengers.

Data are subject to revision. BTS has scheduled Oct. 13 for the release of July traffic data. None of the data are from samples so measures of statistical significance do not apply.

Semi-Annual Tables

Seasonally-Adjusted Tables

Passenger Enplanements on U.S. Airlines, Seasonally-Adjusted (Tables 1-3)

Revenue Passenger-Miles on U.S. Airlines, Seasonally-Adjusted (Tables 4-6)

Available Seat-Miles on U.S. Airlines, Seasonally-Adjusted (Tables 7-9)

Load Factor on U.S. Airlines, Seasonally-Adjusted (Tables 10-12)

Unadjusted Tables

Passenger Enplanements on U.S. Airlines, Unadjusted (Tables 13-15)

Revenue Passenger-Miles on U.S. Airlines, Unadjusted (Tables 16-18)

Available Seat-Miles on U.S. Airlines, Unadjusted (Tables 19-21)

Load Factor on U.S. Airlines, Unadjusted (Tables 22-24)