SAN FRANCISCO — In the wake of last month’s near-collision at San Francisco International Airport, federal officials have made significant changes to how pilots land at the airport and how many air traffic controllers must be working in the tower during nighttime hours, the Bay Area News Group has learned.

The Federal Aviation Administration also plans to begin testing modified radar systems in a few months at its Aeronautical Center in Oklahoma City — and possibly also at the San Francisco airport — to allow the facility’s ground surveillance systems to alert air traffic controllers when an aircraft is attempting to land on a taxiway rather than a runway, as happened in the SFO incident. Those systems were originally designed, according to the FAA, to prevent runway incursions and runway collisions, not taxiway mishaps.

“Just about every safety improvement in aviation was written in blood or the aftermath of an egregious mistake or a screw-up,” retired United Airlines Capt. Ross Aimer, an aviation safety consultant, wrote in an email. “I think all three improvements (by the FAA) are a welcome sight and long time to come. Too bad it took a near disaster for them to finally happen!”

On July 7, Air Canada Flight 759 flew as low as 59 feet off the ground before the pilot aborted his landing, flying dangerously close to four other aircraft awaiting takeoff with an estimated 1,000 passengers on board all the planes, according to an ongoing National Transportation Safety Board investigation. Federal investigators determined that the Air Canada plane dropped off the air traffic controller’s ground surveillance system radar during its final 12 seconds on approach.

Aviation experts have said the near-miss could have triggered one of the worst aviation disasters ever and have criticized the delayed notice of the incident, which allowed the cockpit voice recorder to be overwritten.

Since the close call, the FAA no longer allows visual approaches for aircraft approaching SFO at night with an adjacent parallel runway closed, according to spokesman Ian Gregor. On July 7, Runway 28-Left was closed and darkened, and the Air Canada flight crew told investigators that they shifted their sight-line to the right, causing them to believe Taxiway C was their approved runway Runway 28-Right. Taxiway C runs parallel to 28-right.

“When these conditions prevail, our controllers (will) issue pilots Instrument Landing System approaches or satellite-based approaches, which help pilots line up for the correct runway,” Gregor said.

Sources have said the Air Canada pilot did not use his computer guidance instruments on the July 7 errant approach, which is not uncommon.

Shem Malmquist, a Boeing 777 pilot who has landed many times at SFO, said the new requirements are a positive step as instrument approach would provide precise guidance and clear indications if a pilot veers off course.

“Our human visual systems evolved for land-based creatures that moved only as fast as their legs could carry them,” Malmquist wrote in an email. “We adapt pretty well, but flight with its combination of height, weather and speed, can fool them. The use of an instrument approach keeps the pilots closely aligned with the runway threshold.”

Malmquist said challenges at SFO under such conditions are largely the result of noise-abatement requirements that keep planes at higher altitudes than normal and farther east over the bay. Pilots must take an angled approach, settling into the normal straight-on landing path when they are closer to landing.

In the tower, the FAA will now require two controllers to remain in position during busy late-night hours, Gregor said. Two controllers were working at the time of the SFO incident, he said, but only one was in the tower, and that individual was busy talking to another facility in the final seconds of Air Canada’s botched approach.

“Following the event, SFO tower management adopted a policy requiring two controllers to be on position working traffic until the late-night arrival rush is over,” Gregor said.

Malmquist said that change is good but, as other sources have said, it’s difficult for an air traffic controller at the SFO tower to determine whether an incoming plane is lined up with the runway or adjacent taxiway.

“So reliance on the (air traffic controller) radar becomes more critical — which means it has to work!” Malmquist said. “That said, more eyes are always better as they would offset bias, distraction and other factors.”

Taxiway confusion is not unheard of. In a Dec. 8 FAA memo, the agency reminded pilots that aircraft landing or departing on the wrong runway, taxiway or airport are “among the highest-profile and most dangerous events in aviation.” Those events average about 24 per year, according to the report, but increased to more than 60 in 2016.

“The common denominator for most wrong surface landings/departures was the lack of situational awareness, with closely spaced parallel runways, off set parallel runways, or taxiways which run parallel with runway,” according to the FAA.

The agency provided an example of when a Boeing 737 landed on a parallel taxiway that ran between two parallel runways at Seattle-Tacoma International airport. The FAA also said controller workload or radar limitations that preclude timely intervention by air traffic controllers could contribute to such incidents — both played roles in the SFO incident.

Staff writer Dan Borenstein contributed to this report.