Cancellations - The reporting carriers
canceled 1.7 percent of their scheduled domestic flights
in December 2015, up from both the 1.4 percent
cancellation rate posted in December 2014 and the 1.0
percent rate in November 2015.
For the full year 2015, the reporting carriers
canceled 1.5 percent of their scheduled domestic
flights, an improvement over the 2.2 percent
cancellation rate in 2014.
Tarmac Delays - In December, airlines
reported 11 tarmac delays of more than three hours on
domestic flights and three tarmac delays of more than
four hours on international flights.
In 2015, there were 61 domestic flights with
tarmac delays longer than three hours and 15
international flights with tarmac delays longer than
four hours at U.S. airports.
All reported extended tarmac delays are
investigated by the Department.
Chronically Delayed Flights - At the
end of December, there were no regularly scheduled
flight that were chronically delayed – more than 30
minutes late more than 50 percent of the time – for two
consecutive months or more.
This is the third month in a row in which there
were no chronically delayed flights 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
total delays of 22.17 percent – 5.70 percent of their
flights were delayed by aviation system delays, compared
to 4.84 percent in November; 7.64 percent by
late-arriving aircraft, compared to 5.18 percent in
November; 6.13 percent by factors within the airline’s
control, such as maintenance or crew problems, compared
to 4.60 percent in November; 0.66 percent by extreme
weather, compared to 0.42 percent in November; and 0.06
percent for security reasons, compared to 0.04 percent
In addition, 1.68 percent of flights were
canceled and 0.30 percent were diverted.
Weather - is a factor in both the
extreme-weather category and the aviation-system
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
In December 2015, 32.77 percent of late flights
were delayed by weather, up slightly from 32.31 percent
in December 2014 and from 30.45 percent in November
Detailed information on flight delays and their causes
is available from BTS.
Mishandled Baggage - The U.S. carriers
reporting mishandled baggage data posted a mishandled
baggage rate of 4.04 reports per 1,000 passengers in
December, down from December 2014’s rate of 4.26, but up
from November 2015’s rate of 2.58.
For all of last year, the carriers posted a
mishandled baggage rate of 3.24 per 1,000 passengers,
down from 2014’s rate of 3.61.
Bumping - The report also includes
reports of involuntary denied boarding, or bumping, for
the fourth quarter of 2015 and calendar year 2015 from
U.S. carriers who also report flight delay information.
These carriers posted a bumping rate of 0.72 per
10,000 passengers for the quarter, up from the 0.56 rate
for the fourth quarter of 2014.
The carriers posted a bumping rate of 0.76 per
10,000 passengers last year, an improvement over the
0.92 rate posted in 2014.
Incidents Involving Animals
- In December, carriers reported four incidents
involving the death, injury, or loss of animals while
traveling by air, down from the six reports filed in
December’s incidents involved the deaths of three
animals and injury to one other animal.
For all of last year, carriers reported 35 animal
deaths, injuries to 25 other animals, and three lost
animals, for a total of 63 incidents, up from the 45
total incident reports filed for calendar year 2014.
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
The Department received a total of 81
disability-related complaints in December, up from the
67 complaints received in December 2014, but down from
the 96 complaints received in November 2015.
For all of last year, the Department received 939
disability complaints, up 19.8 percent from the total of
784 received in 2014.
Complaints About Discrimination -
In December, the Department received five complaints
alleging discrimination by airlines due to factors
other than disability – such as race, religion,
national origin, or sex – equal to the total of five
recorded in December 2014, but down from the six
recorded in November 2015.
For all of last year, the Department received
65 discrimination complaints, down 4.4 percent from
the total of 68 filed in 2014.