Baltimore-Washington International Thurgood Marshall Airport showed signs yesterday of a lingering chill from February's twin snowstorms, as a new government report showed it losing ground in a national ranking for on-time performance this year.
Among the nation's top 29 airports for on-time departures, BWI fell from 17th last year to 26th so far in 2010. Seventy-four percent of flights left BWI on time during the first eight months of the year, compared with 79 percent during the same months in 2009, according to a report released by the Bureau of Transportation Statistics.
For on-time arrivals, the airport's on-time percentage fell from 82 percent to 79 percent, and its ranking dropped from 8th to 17th.
The numbers do not necessarily reflect the performance of an airport as much as they do the operations of the carriers that use it, officials say. And they can be heavily influenced by weather conditions — both on the departure end and the arrival end. BWI's ranking would have been several places higher — though still on the low end for departures — if February's performance were excluded.
The airport was at the virtual center of the two record-level snowstorms that hit Baltimore earlier this year. BWI received a cumulative total of 50 inches of snow in February — most of it within a single week.
That month, BWI's on-time departure percentage plummeted to 61.6, the worst in the nation. Its 64.1 percent arrival record ranked 27th out of 29. Flights canceled within seven days of the scheduled departure are included as late flights, according to transportation officials, and BWI had hundreds of cancellations for both arrivals and departures in February.
"The record snowfalls I'm sure played a factor in that," said Paul Flaningan, spokesman for BWI's dominant carrier, Southwest Airlines.
Flaningan said Baltimore "bore the brunt" of the carrier's cancellations. Other airports in the region, such as those in Washington and Philadelphia, also ranked near the bottom in February.
The lower on-time rankings come at a time when BWI has been posting record levels of business. The airport handled an all-time high of 2.2 million passengers in July and followed that with 2.1 million in August for the second-busiest month in its history.
BWI spokesman Jonathan Dean said the influx of passengers would have had no effect on arrival and departure times because there has not been a significant change in the number of flights the airport handles. Rather, he said, the flights going in and out of BWI have been running at higher capacity levels.
Nevertheless, Dean said, BWI is examining the numbers to determine what they may mean.
"We do look at the numbers. We do communicate with our airline partners," he said. The spokesman noted that a large share of BWI's business is conducted by low-fare carriers such as Southwest and AirTran, which operate on tight turnaround times. That, he said, may explain why departure performance lags behind arrival averages.
Dean said the airport has not had complaints from its carriers about its handling of flights, nor has the Federal Aviation Administration found any problems with the air traffic control system. He said the industry pays much more attention to the on-time arrival figure because airlines can frequently make up time and arrive on time despite a delayed departure.
David Smallen, a spokesman for the transportation statistics agency, agreed. He said the government tracks arrivals "in the belief that arrival performance is what matters most to passengers. A flight can depart late and still arrive on time."
By summer, BWI was back in line with the national average in arrivals though it still lagged behind its peers in departures.
But Flaningan said he had no reason to believe the rankings reflected operational problems at BWI.
"It definitely isn't systemic," he said.
Major airports with the highest percentage of on-time departures
1. Seattle, WA (SEA) 89.06
2. Portland, OR (PDX) 88.87
3. Salt Lake City, UT (SLC) 86.69
4. San Diego, CA (SAN) 84.46
5. Phoenix, AZ (PHX) 83.94
Major airports with the lowest percentage of on-time departures
25. Newark, NJ (EWR) 74.86
26. Baltimore, MD (BWI) 74.30
27. New York, NY (JFK) 73.80
28. Miami, FL (MIA) 72.73
29. Chicago, IL (MDW) 71.27
Source: Bureau of Transportation Statistics Report, Jan. 1-Aug. 31, 2010