The FAA has opened an investigation into the jolt on a United Airlines flight that injured two passengers when the pilots responded to an onboard midair collision system warning. United Airlines says as flight 2428 from Newark, New Jersey, was descending into San Francisco International Airport last Thursday, it “slowed its descent to account for another aircraft at a lower altitude.” Both injured passengers were taken to the hospital, United said in a statement. An FAA incident report says one passenger received serious injuries and another minor injuries last Thursday when the pilots responded to a traffic collision avoidance system resolution advisory or “TCAS RA.” Collision resolution advisories are treated as extreme warnings of a possible collision with another airplane and pilots are required to act immediately. Data from FlightRadar24 shows the incident took place at 31,000 feet as the flight was near Lake Berryessa, about 70 miles north of San Francisco. FlightRadar24 says a Southwest Airlines flight was 3,000 feet below the United flight and a SkyWest flight was 1,000 feet below. In a statement, the FAA – which is responsible for controlling air traffic – said “there was no loss of safe separation.”<br/>