The Federal Aviation Administration has modified nighttime landing procedures and control tower staffing requirements at San Francisco International airport following a close call last month involving an Air Canada Airbus A320.

Controllers at the airport will no longer permit pilots to perform visual approaches at night "when an adjacent parallel runway is closed", the agency tells FlightGlobal.

"When these conditions prevail, our controllers issue pilots instrument landing system approaches or satellite-based approaches, which help pilots line up for the correct runway," says the FAA in a statement.

The agency adds that San Francisco's tower management now requires two controllers be working in the tower "until the late-night arrival rush is over".

The changes took effect "right after" a 7 July incident during which an Air Canada A320 operating flight 759 from Toronto nearly landed on a busy taxiway at San Francisco, the FAA says.

Controllers had cleared the pilots to land on runway 28R, but they lined up on the parallel taxiway C, which four aircraft occupied at the time, including a United Airlines Boeing 787, according to the NTSB and to air traffic control recordings.

The A320 pilots overflew the taxiway by about 0.25nm before controllers ordered it to go around. They descended to minimum altitude above the taxiway of 59ft and passed within 29ft laterally of one aircraft and 100ft above two others, according to US and Canadian investigators.

At the time of the incident, San Francisco's runway 28L was closed and unlit.

Pilots of the Air Canada A320 told US investigators they thought the lighted runway was 28L and that taxiway C was runway 28R, the NTSB said.

Source: Cirium Dashboard