Commercial airliners nearly collide in Hawaii; controller error blamed

A near collision of two planes flying over Hawaii more than two weeks ago was caused by miscommunication from Honolulu's air traffic control tower, according to an incident report obtained by CBS News.

The report said a controller did not notice that the planes were on a collision course, reports CBS News correspondent Jeff Pegues.

At 11:16 p.m. on April 25, the pilot for United Airlines flight 1205 could be heard initiating an abrupt dive.

"We've got an emergency descent going!" he said.

The flight was cruising at more than 30,000 feet. It made the 600-foot drop in 60 seconds to avoid a head-on collision with U.S. Airways flight 432 traveling at the same altitude, the planes coming within 2.2 miles of each other.

"It was a really violent, scary experience," flight 1205 passenger Kevin Townsend said. "It felt kind of like the plane had gone dead in the air and started dropping."

Former head of the NTSB and CBS news transportation and safety expert Mark Rosenker said when close calls occur, a traffic collision avoidance system, or TCAS, on board will alert pilots.

"TCAS, in this case, gave the appropriate instructions to both pilots," Rosenker said. "One would descend his aircraft, the other would climb and that got away from a situation where potentially you could create a mid-air collision."

In the initial report conducted by Honolulu air traffic control, the tower navigating the two planes involved, indications of human error were found. It noted a controller "...did not notice the confliction."

In August 2012 an error made by air traffic control put three planes at risk for colliding at Ronald Reagan National Airport outside Washington.

"We were cleared at the river back there. What happened?" the pilot of U.S. Airways flight 3329 said.

Rosenker points out that human error might be unavoidable, but the systems in place to prevent accidents are working.

"We have seen a significant reduction in mid-air collisions since we have adopted these programs and this technology on-board commercial aircraft," he said.

The FAA and the NTSB have a team of investigators looking into the incident. Both United Airlines and U.S. Airways said they are working with authorities to figure out exactly what happened.