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Airline On-Time Performance in May Improves from Previous Month but Down From Last Year

Airline On-Time Performance in May Improves from Previous Month but Down From Last Year


DOT 80-11
Bill Mosley

Thursday, July 7, 2011 - The nations largest airlines posted an on-time arrival mark in May that was an improvement from Aprils showing but down from the performance recorded in May 2010, according to the Air Travel Consumer Report released today by the U.S. Department of Transportation (DOT).

Information filed with the Bureau of Transportation Statistics (BTS), a part of DOTs Research and Innovative Technology Administration, shows that the 16 carriers reporting on-time performance recorded an overall on-time arrival rate of 77.1 percent in May, down from the 79.9 percent on-time rate of May 2010 but up from April 2011s 75.5 percent rate.

The monthly report also includes data on lengthy tarmac delays, on-time performance, chronically delayed flights, flight cancellations, and the causes of flight delays filed with the Department by the reporting carriers. In addition, the report contains information on reports of mishandled baggage filed by consumers with the carriers, and consumer service, disability and discrimination complaints received by DOTs Aviation Consumer Protection Division. This report also includes reports of incidents involving pets traveling by air, as required to be filed by U.S. carriers.

Tarmac Delays

The carriers filing on-time performance with the Department reported 16 total tarmac delays of more than three hours reported in May by the airlines that file on-time performance data with DOT, compared to one in May 2010 and four in April 2011.

Fourteen of the delays involved American Eagle Airlines flights arriving at Chicagos OHare airport on May 29, a day in which the Chicago area experienced weather issues. The other two long tarmac delays involved an American Eagle flight from New York JFK to Indianapolis on the same date, and a May 11 Southwest Airlines flight from Denver to Seattle. All of the reported tarmac delays are under investigation by the Department.


During May, the carriers canceled 2.1 percent of their scheduled domestic flights, compared to 1.2 percent in May 2010 and 2.0 percent in April 2011.

Chronically Delayed Flights

At the end of May, there was only one flight that was chronically delayed more than 30 minutes late more than 50 percent of the time for three consecutive months. There were an additional 46 flights that were chronically delayed for two consecutive months. There were no chronically delayed flights for four 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 May, the carriers filing on-time performance data reported that 6.67 percent of their flights were delayed by aviation system delays, compared to 7.57 percent in April; 7.71 percent by late-arriving aircraft, compared to 8.35 percent in April; 5.47 percent by factors within the airlines control, such as maintenance or crew problems, compared to 5.68 percent in April; 0.68 percent by extreme weather, compared to 0.55 percent in April; and 0.05 percent for security reasons, compared to 0.04 percent in April.  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 DOTs 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.

Data collected by BTS also show the percentage of late flights delayed by weather, including those reported in either the category of extreme weather or included in National Aviation System delays. In May, 42.45 percent of late flights were delayed by weather, up 8.37 percent from May 2010, when 39.17 percent of late flights were delayed by weather, and up 6.47 percent from April when 39.87 percent of late flights were delayed by weather.

Detailed information on flight delays and their causes is available on the BTS site on the World Wide Web at

Mishandled Baggage

The U.S. carriers reporting flight delays and mishandled baggage data posted a mishandled baggage rate of 3.52 reports per 1,000 passengers in May, up from both May 2010s rate of 3.23 and April 2011s rate of 3.24.

Incidents Involving Pets

In May, carriers reported two incidents involving the loss, death or injury of pets while traveling by air, down from the three reports filed in May 2010 and four reports filed in April 2011.  Mays incidents involved the death of one pet and the injury of one pet. 

Complaints About Airline Service

In May, the Department received 1,062 complaints about airline service from consumers, up 32.9 percent from the 799 complaints filed in May 2010, and up 20.8 percent from the 879 received in April 2011.

Complaints About Treatment of Disabled Passengers

The report also contains a tabulation of complaints filed with DOT in May against airlines regarding the treatment of passengers with disabilities.  The Department received a total of 57 disability-related complaints in May, up from both the total of 40 complaints filed in May 2010 and the 54 complaints received in April 2011.

Complaints About Discrimination

In May, the Department received 10 complaints alleging discrimination by airlines due to factors other than disability such as race, religion, national origin or sex equal to the total of 10 recorded in both May 2010 and April 2011.

Consumers may file their complaints in writing with the Aviation Consumer Protection Division, U.S. Department of Transportation, C-75, W96-432, 1200 New Jersey Ave. SE, Washington, DC 20590; by voice mail at (202) 366-2220 or by TTY at (202) 366-0511; or on the web at

Consumers who want on-time performance data for specific flights should call their airlines reservation number or their travel agent.  This information is available on the computerized reservation systems used by these agents.  The information is also available on the appropriate carriers website.

The Air Travel Consumer Report can be found on DOTs World Wide Web site at It is available in pdf and Microsoft Word format.

Air Travel Consumer Report May 2011
Key On-Time Performance and Flight Cancellation Statistics

Based on Data Filed with the Bureau of Transportation Statistics by the 16 Reporting Carriers


77.1 percent on-time arrivals

Highest On-Time Arrival Rates

1. Hawaiian Airlines 91.4 percent

2. Alaska Airlines 90.7 percent

3. AirTran Airways 85.9 percent

Lowest On-Time Arrival Rates 

1. American Eagle Airlines 67.6 percent

2. American Airlines 70.3 percent

3. ExpressJet Airlines 71.6 percent

Flights with Longest Tarmac Delays

1. American Eagle Airlines flight 3873 from El Paso, TX to Chicago OHare, 5/29/11 delayed on tarmac 223 minutes

2.American Eagle Airlines flight 4185 from Cleveland to Chicago OHare, 5/29/11 delayed on tarmac 210 minutes

3. American Eagle Airlines flight 4122 from Tri-City Airport, TN to Chicago OHare, 5/29/11 delayed on tarmac 208 minutes

4. American Eagle Airlines flight 4230 from Wichita, KS to Chicago OHare, 5/29/11 delayed on tarmac 201 minutes

4. American Eagle Airlines flight 4168 from Richmond, VA to Chicago OHare, 5/29/11 delayed on tarmac 201 minutes

Highest Rates of Canceled Flights

1. American Eagle Airlines 6.6 percent

2. American Airlines 5.5 percent

3. ExpressJet Airlines 3.9 percent

Lowest Rates of Canceled Flights

1. Frontier Airlines 0.1 percent

2. Continental Airlines 0.2 percent

3. Alaska Airlines 0.3 percent