Two Hong Kong-bound flights carrying more than 600 people narrowly missed each other over the Asian city, according to officials, after pilots scrambled to react to warning signals.
A Cathay Pacific Boeing 777 arriving from New York and a Dragonair Airbus A330 from Taiwan were both told to hold off landing due to bad weather on September 18 but strayed into each other's path.
Airline officials said they were one nautical mile (2,000 metres) apart at the same altitude southwest of Hong Kong airport when the traffic collision avoidance system warning sounded.
The Dragonair pilot put his aircraft, carruying 284 passengers and 12 crew, into an immediate climb while the Cathay flight, with 299 passengers and 18 crew on board, descended to resolve the conflict.
According to Hong Kong's former civil aviation chief the two planes came within six seconds of impact, based on their distance and normal aircraft speed.
"The chance of a crash is absolutely high. The passengers really came back from hell," Albert Lam told The Standard newspaper.
A spokesman for Cathay Pacific, which also owns Dragonair, said that there had been a "loss of separation" but said: "There was no risk of collision and at no time was the safety of the flights compromised.
"At the closest, they were one nautical mile (2,000 meters) apart when abeam from each other with increasing vertical separation."
Both flights landed at the airport without incident, 14 minutes apart.
Cathay said the incident has been reported to civil aviation authorities and pledged to cooperate with the probe.