NerdWallet, a website that launched in 2010, found by aggregating data that the on-time percentage for arrivals of airplanes in San Francisco dropped slightly from 73 percent to 70 percent and on-time departures slipped from 76 percent to 75 percent from March 2013 to February 2014.
The length of average delays for arrivals increased from 66.6 minutes to 67.9 minutes and for departures grew from 61.9 minutes to 62.9 minutes, according to the analysis drawing from the U.S. Department of Transportation Air Travel Consumer Report and Bureau of Transportation statistics.
While delay times have not risen dramatically, NerdWallet noted that the airport implemented its closely-spaced parallel runways procedure last November in an effort to improve arrival times by allowing two aircraft to be paired together and run staggered approaches on separate runways.
“It’s not terrible,” said NerdWallet senior analyst Divya Raghavan of the delay increase. “It’s just surprising since they went through so much effort and so much work to implement the new procedure.”
Airport spokesman Doug Yakel said he could not comment without performing additional data analysis, but noted that NerdWallet’s findings did not seem to take into account differences in weather-related delays between the years.
And in fact, Yakel said, the parallel runways procedure has upped arrivals on days with inclement weather from about 27 to 30 per hour to 33.
“Even in a short time we’ve seen an increase,” he said. “And as air traffic controllers and everybody gets more experienced with the procedure, it’s a number we expect will increase as time goes on.”
NerdWallet released its analysis in light of the airport shutting down two of its four runways Saturday for the next three to four months to complete the final phase of a federally mandated runway safety project.
“Think before you book your flight this summer,” Raghavan advised. “Book out of Oakland or somewhere else because SFO is going to have more delays in general.”
But Yakel countered that this summer will be “business as usual for SFO” while the two runways get an engineered material arresting system installed for safety. The airport, he noted, also operated only two runways for more than 100 days last year.
The airport has minimized the potential for disruption during the runway construction, he said, “through the support of airlines of SFO who have actually scaled back their flight schedule over the summer to accommodate this construction work.”