A much-publicized near-miss incident at San Francisco International Airport in July has led to the introduction of new rules for air traffic using the airport at night, and for controllers working at the airport.

On July 7, Air Canada Flight 759 was approaching what the pilots assumed was runway 28 Right at the airport during the hours of darkness. In fact, the aircraft was lined up with the parallel taxiway to the right of the runway, which at the time had three airliners waiting for take-off clearance.

When a go-around was initiated, it was estimated that the Air Canada Airbus jet had descended as low as 59 feet above the waiting aircraft. Seconds later and a collision would have been certain, with more than 1,000 lives at risk when all aircraft were taken into account. Potentially one of the worst air disasters in the country's history was narrowly averted.

Recently released CCTV footage (see video above) shows the approaching aircraft and its proximity to those on the ground. The incident has sparked much public interest, and now the Federal Aviation Administration (FAA) has announced new measures to prevent a repeat of the incident.

The Air Canada jet on the night of the incident was operating under visual flight rules, whereby the pilots navigate by looking out of the window. Under the new rules, aircraft will not be permitted to operate into SFO under visual rules at night when one of the parallel runways is closed, as it was on July 7. Pilots must instead use the Instrument Landing System, which will safely direct them to the correct runway.

In another move, the FAA has ruled that two air traffic controllers must be present in the SFO tower during the busy night period. These policies have been put into immediate effect following the FAA's announcement.

A more wide-ranging measure is also to be introduced by the FAA. New ground-based radar is to be tested, which will be able to alert controllers to aircraft which are approaching a taxiway or incorrect runway. This testing will take place in a few months' time at the Aeronautical Center in Oklahoma City and will involve modifying existing ground radar that works to prevent runway incursions.

Incidences of aircraft incorrectly landing on taxiways are surprisingly common around the world, and the situational awareness of pilots and the ability of tower controllers to determine the path of approaching aircraft are usually the cause.

As has been the case with many safety improvements introduced over the years, the lessons learned in incidents highlight gaps and facilitate the development of new technology.

While the actions of the Air Canada crew were not unusual for many airliners approaching San Francisco at night, it thankfully did not end in loss of life. However, it has highlighted the need for greater awareness of incorrect approaches and is likely to see the new technology introduced to major airports worldwide.