SAN FRANCISCO INTERNATIONAL AIRPORT (KPIX) – If think San Francisco International Airport is crowded now, just wait until September.

Starting September 7, runway 28 Left (28L) is going out of service for major, extended repairs. For 20 days, heavy wide-body aircraft will have only one runway to use.

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United SFO Managing Director, Jon Gooda says, United Airlines is getting ready.

“All the airlines, United included, did reduce our schedules for the period of the runway closure, so there’ll be less pressure on the airport during that period,” said Gooda.

Runway 28L is one of the principal runways for all international landings. The core base layer under it is failing. Nearly 2000 feet will be removed and rebuilt. The runway’s lighting and drainage will be replaced.

When SFO has a problem, it affects the entire region. Oakland International Airport spokesperson, Keonnis Taylor says Oakland will absorb some of the diverted flights.

“Twenty days is a long time but we have the benefit of preparation here and we expect flights to be on time, and for operations to be smooth,” said Taylor.

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If the aviation industry has taught us anything, it is to expect the unexpected. Travelers at SFO agree that anything can happen.

Patti Dedominics flies through SFO often.

“Oh! That’ll be a disaster!” she said.

“So, stay out of here in September,” laughed her husband Marco. “I’d probably change airports, to something less busy.”

In response, United made a surprise announcement.

“We made a decision to waive those change fees for customers that are impacted by any delay,” explained Gooda.

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SFO says the repairs should be completed by September 27, and will cost $16.1 million.