In 2016, the reporting carriers canceled 1.17 percent of their scheduled domestic flights, an improvement over the 1.5 percent cancellation rate in 2015 and the lowest in the 22 years with comparable numbers, according to the Air Travel Consumer Report (ATCR).

The previous low was 1.24 percent in 2002. The reporting carriers canceled 1.6 percent of their scheduled domestic flights in December 2016, an improvement over the 1.7 percent cancellation rate posted in December 2015, but up from the 0.3 percent rate in November 2016.

In 2016, the carriers posted a mishandled baggage rate of 2.70 per 1,000 passengers, down from 2015’s rate of 3.13 and the lowest annual rate since DOT started collecting mishandled baggage report data in September 1987. The previous low was 3.09 in 2012. The U.S. carriers reporting mishandled baggage data posted a mishandled baggage rate of 3.58 reports per 1,000 passengers in December, down from December 2015’s rate of 3.97, but up from November 2016’s rate of 2.02.

The carriers posted a bumping rate of 0.62 per 10,000 passengers in 2016, an improvement over the 0.73 rate posted in 2015 and the lowest annual rate based on historical data dating back to 1995. The previous low was 0.72 in 2002. These carriers posted a bumping rate of 0.54 per 10,000 passengers for the quarter, down from the 0.69 rate for the fourth quarter of 2015.

The consumer report also includes data on on-time performance, tarmac delays, chronically delayed flights, and the causes of flight delays filed with the Department’s Bureau of Transportation Statistics (BTS) by the reporting carriers. In addition, the consumer report contains a tally of aviation service complaints filed with DOT’s Aviation Consumer Protection Division by consumers regarding a range of issues such as flight problems, baggage, reservation and ticketing, refunds, customer service, disability, and discrimination.

The report also includes information about the total number of animals that died, were injured, or were lost during air transport in December 2016 and calendar year 2016, as filed by the air carriers with the Aviation Consumer Protection Division. In addition, the report introduces data about the total number of animals transported by airlines during the calendar year.

On-Time Performance

For the full year 2016, the reporting carriers posted an on-time arrival rate of 81.4 percent, up from 79.9 percent in 2015. The reporting carriers posted an on-time arrival rate of 75.6 percent in December 2016, down from both the 77.8 percent on-time rate in December 2015 and the 86.5 percent mark in November 2016.

Tarmac Delays

In December, airlines reported 21 tarmac delays of more than three hours on domestic flights and three tarmac delays of more than four hours on international flights. Fourteen of the long domestic delays involved Frontier Airlines and took place in Denver during a snowstorm on December 16 and 17. In 2016, there were 84 domestic flights with tarmac delays longer than three hours and 36 international flights with tarmac delays longer than four hours at U.S. airports. All reported extended tarmac delays are being investigated by the Department.

Chronically Delayed Flights

At the end of December, there were no flights that were chronically delayed – more than 30 minutes late more than 50 percent of the time – for two consecutive months or more. A list of flights that were chronically delayed for a single month is available from BTS.

Causes of Flight Delays

In December, the carriers filing on-time performance data reported that 24.38 percent of their flights were delayed – 6.70 percent of their flights were delayed by aviation system delays, compared to 4.43 percent in November; 8.46 percent by late-arriving aircraft, compared to 4.51 percent in November; 6.59 percent by factors within the airline’s control, such as maintenance or crew problems, compared to 3.83 percent in November; 0.70 percent by extreme weather, compared to 0.26 percent in November; and 0.04 percent for security reasons, compared to 0.03 percent in November.

In addition, 1.62 percent of flights were canceled and 0.27 percent were diverted.

Weather is a factor in both the extreme-weather category and the aviation-system category. This includes delays due to the re-routing of flights by DOT’s Federal Aviation Administration in consultation with the carriers involved. Weather is also a factor in delays attributed to late-arriving aircraft, although airlines do not report specific causes in that category.

BTS uses the data collected from airlines to determine the percentage of late flights delayed by weather, which includes those reported in the categories of extreme weather, late-arriving aircraft, and National Aviation System delays. In December, 28.36 percent of late flights were delayed by weather, down from 32.77 percent in December 2015 and from 29.36 percent in November 2016.

Detailed information on flight delays and their causes is available from BTS.

Incidents Involving Animals

In December, carriers reported five incidents involving the death, injury, or loss of an animal while traveling by air, up from the four reports filed in both December 2015 and in November 2016. December’s incidents involved the deaths of three animals and injuries to two other animals. For all of last year, carriers reported 26 animal deaths, injuries to 22 other animals, and no lost animals, for a total of 48 incidents, down from the 63 total incident reports filed for calendar year 2015.

The ATCR also introduces data about the total number of animals transported by airlines during the calendar year. In 2015, 534,537 animals were transported, for a rate of 1.18 incidents per 10,000 animals transported. In 2016, 523,743 animals were transported, for a rate of 0.92 incidents per 10,000 animals transported.

Complaints About Airline Service

For all of last year, the Department received 17,904 complaints, down 11.3 percent from the total of 20,175 received in 2015. In December, the U.S. Department of Transportation received 1,726 complaints about airline service from consumers, up 10.2 percent from the total of 1,566 filed in December 2015 and up 69.2 percent from the 1,020 received in November 2016.

Complaints About Treatment of Disabled Passengers

The report also contains a tabulation of complaints filed with DOT in December against airlines regarding the treatment of passengers with disabilities. The Department received a total of 58 disability-related complaints in December, down from both the 83 complaints received in December 2015 and the 73 complaints received in November 2016. For all of last year, the Department received 862 disability complaints, down 8.7 percent from the total of 944 received in 2015. All complaints alleging discrimination on the basis of disability are investigated.

Complaints About Discrimination

In December, the Department received five complaints alleging discrimination – four complaints regarding race and one complaint regarding religion. This is equal to the total of five recorded in December 2015, but down from the 14 recorded in November 2016.

For all of last year, the Department received 94 discrimination complaints – 65 complaints regarding race, 12 complaints regarding national origin, two complaints regarding color, eight complaints regarding religion, and seven complaints regarding sex.

This is an increase of 44.6 percent from the total of 65 filed in 2015. All complaints alleging discrimination are investigated to determine if there has been a violation(s) of the passenger’s civil rights.