The Federal Aviation Administration is investigating an incident in which a passenger jetliner had to take evasive action to avoid a mid-air collision with another jet near the Big Island.
The FAA said the incident happened April 25 about 200 miles northeast of Kona and about 33,000 feet in altitude.
United Airlines flight 1205 had departed Kona Airport and was heading to the mainland when its collision alert system went off. It then dropped 600 feet in 60 seconds to avoid a US Airways jet headed toward Kona.
It happened suddenly, according to United passenger Kevin Townsend of San Francisco.
"I'm looking down the aisle and there's hundreds of people in front of me," he said. "People start screaming, there's noise of things that weren't secured falling around."
The United pilots were responding to the Traffic Collision Avoidance System, or TCAS, which is on all larger passenger jetliners. The system will send an alert if two planes get too close to one another.
"The two TCAS instruments will talk to each other, say 'one go up' and 'one go down,'" said retired pilot and aviation expert Peter Forman. "It's a great safety enhancement, and we saw it work."
According to the FAA, the two aircraft were eight miles apart when the TCAS aboard the United Boeing 757 went off. Preliminary data show at their closest approach, they were five miles apart, but just 800 feet in altitude separated them.
Forman said that's pretty close, especially when you have two jetliners traveling at close to 600 miles per hour.
"Sixty miles an hour is one mile a minute. Six hundred miles an hour is ten miles a minute closure rate," he said.
Another close call in Hawaii skies happened in January 2012, when a Japan Airlines 767 arriving from Tokyo nearly collided with a UPS MD-11 about 15 miles west of Honolulu. A new controller was retrained following that incident.
A joint FAA-NTSB investigative team arrived at the Honolulu Control Facility Thursday to look into the latest incident.
Townsend said in a blog that shortly after the quick descent, a flight attendant told passengers that the pilot had taken an evasive action to avoid another plane, and that the in-flight entertainment would be free.
Townsend said he'll still fly, but is still a little shaken.
"I don't think there's some epidemic of near accidents that's occurring, but it was a jarring experience dodging another plane."