With a seemingly ever-present fog enveloping the hub, flying into San Francisco International Airport can be a particularly cruel guessing game for airlines and passengers.
However, thanks to a new program being developed by NASA, airlines will soon have more precise information on when that fog will clear — keeping hundreds of thousands of passengers from being stuck taxiing on tarmacs or stranded at distant airports wondering when their SFO-bound flight will depart.
Currently, airlines have set arrival schedules for SFO, but when fog rolls over the airport, the Federal Aviation Administration sends out a ground-delay program, which halts all flights for San Francisco until the conditions improve, said Michael McCarron, spokesman for SFO. Those ground delays can range from 45-minute setbacks to all-day affairs, McCarron said.
On average, SFO experiences inclement conditions about half the year, during which time the number of hourly arriving flights is reduced from 60 to 30. In July alone, 3,086 flights were delayed coming into SFO because of weather, resulting in more than 3,800 hours of lost travel time, according to the U.S. Bureau of Transportation Statistics.
NASA hopes to cut down on those numbers with a new weather-coordinating program. Using tools developed at its Ames Research Center near Mountain View, NASA can now predict almost precisely when fog will lift above SFO, according to Parimal Kopardekar, a project manager at the institute.
By calculating fog dissipation probabilities, NASA will be able to relay more exact weather advisories to the FAA so it can coordinate scheduling with airlines across the country. This will greatly reduce the uncertainty of flying into fog-ridden SFO, Kopardekar said.
“Right now, these airlines have a buffer zone when they’re not sure if they can land at SFO,” said Kopardekar. “The fog may be cleared at 11 a.m., but because of the current scheduling programs, planes wouldn’t even be able to land until 1 p.m. This program would ensure that as soon as the fog clears, planes will be ready to land.”
By combining the fog data with the number of planes scheduled to arrive, NASA can coordinate nearly exactly what times flights should leave for SFO — eliminating the guessing game that plagues many a flight to the airport.
NASA has worked on the development part of the program, and will be ready for operational use of the plan next summer, when fog is the most present at SFO. Not only will the program give passengers more information about when they will land at the hub, it’s projected to save airlines a collective $10 million next summer, Kopardekar said. Those savings will come from reduced jet fuel usage and cutting down on the workloads of air traffic controllers, Kopardekar said.
Along with NASA, the National Weather Service, the Massachusetts Institute of Technology, the FAA and Mosaic ATM — a private research company — worked on the project.
Nearly 20 million travelers flew into SFO last fiscal year.
Using tools from the Ames Research Center, NASA forecasts when fog will lift over SFO and then sends out weather advisories to all flights scheduled to arrive in SFO that day.
Using this data, airlines from across the country know exactly when their flights should depart for SFO to avoid the fog and scheduling conflicts. Passengers are no longer stuck at airports wondering when their flight will leave, and planes won’t taxi on tarmacs waiting to get clearance to take off.
60 Flights that can arrive hourly at SFO under good weather conditions
30 Flights that can arrive hourly at SFO under bad weather conditions
50 Percent of the year SFO experiences bad weather conditions
76.83 On-time performance rate for nation’s airports
69.18 On-time performance rate at SFO
16,716 Weather-related delays at SFO in 2011*
18,081 Travel hours lost this year to weather-related delays*
Sources: SFO, U.S. Bureau of Transportation Statistics