Another United flight out of SFO had an issue on Saturday morning, but this one was due to natural causes, or, rather, a random collision with nature.

The flight, UA-1003, left SFO on time at 5:04 am Saturday, bound for Denver. But the 737-9 MAX jet suffered a bird strike as it was taking off that did damage to the pilot's side window, according to a report from the FAA obtained by the Chronicle.

The plane ascended to 5,000 feet before turning back and landing again at SFO 25 minutes later. All passengers and their luggage had to be moved onto a new plane, and the flight proceeded on to Denver, three and a half hours delayed.

The Chronicle found via flight records that the damaged plane, with its window repaired, was put back into service by Sunday morning.

While bird strikes are fairly routine, they rarely disrupt flights. SFO records an average of 18 bird strikes for every 100,000 flights in and out.

Still, as the Chronicle notes, there was another bird strike in California that same day that caused a plane to turn around. This was an Oakland-bound Southwest flight out of San Diego, which had to return to the gate on Saturday and passengers were put on a new plane which arrived after a 90-minute delay.

A bird strike was also blamed for another damage incident on a United flight out of SFO in February. In that incident, the strike caused damage to a wing flap on a Boeing 757-200 jet that was visible out of passengers' side windows.

That Boston-bound flight had to divert to Denver for an emergency landing, but the landing came off without incident.

Saturday's incident comes after a string of apparent equipment- or maintenance-related incidents on Boeing jets, many of them United jets flying out of SFO.

A Japan-bound jet out of SFO lost a tire during takeoff earlier this month and had to divert to Los Angeles.

Another United flight bound for Japan out of SFO returned to the gate before leaving the runway last week due to an engine-start issue.

Previously: Boston-Bound United Flight Out of SFO Makes Emergency Landing After Piece of Wing Flap Tears Off

Photo: Chris Leipelt