It’s an axiom of the airline industry that on a typical day,
operational performance is best in the morning then goes downhill as
difficulties related to weather, mechanical problems and other issues back up
However, some airlines recover faster than others in the
evening as they reduce their number of flights, according to figures provided
by the flight-data service company FlightStats, and the data suggests that some
of this is due to operating hub-and-spoke versus point-to-point scheduling
On-time arrival data from January through August of this
year for six U.S. airlines shows that in each case the airline’s on-time
percentage peaked by 7 a.m. before declining into the early evening hours. For
example, American began its days with an on-time performance of 89.7% during
the 5 a.m. to 6 a.m. hour. That number declined steadily thereafter before
bottoming out at 71.2% between 6 p.m. and 7 p.m.
FlightStats data showed a similar pattern for the other
carriers, including United, Delta, JetBlue, Spirit and Southwest. But
comparative results among the carriers began diverging at night after some
airlines began delivering improved on-time results more dramatically and earlier
Delta, for example, had its lowest hourly on-time percentage
during the first eight months of this year between 6 p.m. and 7 p.m., with a
figure of 77.5%. But the carrier improved its performance to 83.7% by the 10
p.m. to 11 p.m. hour, when it operated almost two-thirds fewer flights than its
Conversely, Southwest did not hit its lowest performance
hour until between 10 p.m. and 11 p.m.
In fact, among the six carriers, each of the legacy airlines
saw its worst on-time performance earlier in the evening than Southwest, Spirit
and JetBlue did.
American and Delta each hit bottom between 6 p.m. and 7 p.m.
United had its worst on-time results between 8 p.m. and 9 p.m., JetBlue and
Spirit got their worst results one hour later, and Southwest’s was an hour
In an interview, FlightStats senior vice president of
airlines Jim Hetzel attributed the faster evening recovery by the Big Three carriers
to their hub-and-spoke operating models.
While Southwest especially, but also Spirit and JetBlue,
often fly an aircraft from point A to point B then on to additional cities,
American, Delta and United are more likely to fly from a hub to a second
location, then return the aircraft to the hub.
“If you get a delay early on, that delay is going to get
carried over from point A to point B to point C to point D,” Hetzel said of the
Nevertheless, point-to-point operations have certain
advantages over the out-and-back flying of hub-centric airlines, according to
Seth Kaplan, managing editor of the newsletter Airline Weekly.
For one thing, Southwest can offer a more diverse
combination of routes than its legacy rivals.
In addition, point-to-point travel enables carriers to move
their planes with shorter turnaround times. In large part, Kaplan said, that’s
because airlines that run out-and-back networks try to schedule surges of
similarly timed flights into and out of their hubs. Doing so enables them to
offer convenient connections to more flyers. But timing flights under such a
model means a carrier sometimes has to hold a plane on the ground in order to
align with a surge.
Unencumbered by such concerns, point-to-point operations
typically move their planes out of each airport more quickly.
Brett Snyder, who runs the aviation blog Cranky Flier, said
the shorter ground times that point-to-point planes usually see are a likely
reason that an airline like Southwest doesn’t recover with on-time performance
as well during the evening as hub-and-spoke carriers.
“In general, they are just using very different strategies
for running the airline,” Snyder said.