In July, the Department of Transportation (DOT) received 2,466 complaints about airline service from consumers, up 91.8 percent from the 1,286 complaints in July 2011, according to the DOT's Air Travel Consumer Report. The July total was up 49.2 percent from the 1,653 complaints received in June 2012.
Airlines reported 18 tarmac delays of more than three hours on domestic flights and one tarmac delay of more than four hours on international flights in July, according to the report.
Sixteen of the long domestic tarmac delays took place on July 13 and involved flights bound for or departing from Chicago O'Hare Airport, where severe storms affected the area that day. All of the reported tarmac delays are under investigation, the DOT notes.
The larger U.S. airlines have been required to file complete reports on their long tarmac delays for domestic flights since October 2008. Under a new rule that took effect Aug. 23, 2011, all U.S. and foreign airlines operating at least one aircraft with 30 or more passenger seats must report lengthy tarmac delays at U.S. airports, DOT says.
Also beginning Aug. 23, 2011, carriers operating international flights may not allow tarmac delays at U.S. airports to last longer than four hours. There is a separate three-hour limit on tarmac delays involving domestic flights, which went into effect in April 2010.
Exceptions to the time limits for both domestic and international flights are allowed only for safety, security, or air traffic control-related reasons. Severe weather could cause or exacerbate such situations, DOT reports.
On-Time Performance: The reporting carriers posted an on-time arrival rate in July of 76.0 percent, down from both July 2011's 77.8 percent mark and from June 2012's 80.7 percent.
Cancellations: The reporting carriers canceled 1.4 percent of their scheduled domestic flights in July, down from the 1.7 percent cancellation rate posted in July 2011, but up from June 2012's cancellation rate of 1.1 percent.
Chronically Delayed Flights: At the end of July, there were four flights that were chronically delayed - more than 30 minutes late more than 50 percent of the time - for three consecutive months. There were 14 additional flights that were chronically delayed for two consecutive months. There were no chronically delayed flights for four consecutive months or more.
Causes of Flight Delays: In July, the carriers filing on-time performance data reported that 6.07 percent of their flights were delayed by aviation system delays, compared to 4.82 percent in June; 9.03 percent by late-arriving aircraft, compared to 6.98 percent in June; 6.32 percent by factors within the airline's control, such as maintenance or crew problems, compared to 5.62 percent in June; 0.82 percent by extreme weather, compared to 0.50 percent in June; and 0.04 percent for security reasons, equal to 0.04 percent in June.
DOT notes that 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.
Data collected by BTS also shows 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 July, 40.71 percent of late flights were delayed by weather, up 6.54 percent from July 2011, when 38.21 percent of late flights were delayed by weather, and up 35.79 percent from June when 29.98 percent of late flights were delayed by weather.
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 July, down from July 2011's rate of 3.72, but higher than June 2012's rate of 3.35.