American B772 and China Airlines B744 over Bering Sea on Aug 15th 2014, near collision

Last Update: May 29, 2015 / 15:12:41 GMT/Zulu time

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Photo of China Airlines B-18722, Boeing 777-200 — China Airlines B-18722, Boeing 777-200 (Photo credit: Prayitno / Thank you for (6 millions +) views / Flickr / License: CC by)

Incident Facts

Date of incident
Aug 15, 2014

Classification
Incident

Cause
Near collision

Airline
China Airlines

Flight number
CI-5254

Departure
Taipei, Taiwan

Destination
Anchorage, United States

Aircraft Registration
B-18722

Aircraft Type
Boeing 777-200

ICAO Type Designator
B772

A China Airlines Boeing 747-400 freighter, registration B-18722 performing flight CI-5254 from Taipei (Taiwan) to Anchorage,AK (USA), was enroute at FL350 near N52 E170, about 100nm southwest of Attu Island, when at 21:13L (05:13Z Aug 16th) the crew requested via controller–pilot data link communication (CPDLC) to climb to FL370. Anchorage Control, sector 11R, cleared the aircraft to climb to FL370 by 05:20Z via CPDLC.

An American Airlines Boeing 777-200, registration N773AN performing flight AA-183 from Los Angeles,CA (USA) to Shanghai Pudong (China), was enroute at FL360 near N54 E178, about 220nm northeast of Attu Island, when at 21:16L (05:16Z Aug 16th) the crew requested a climb to FL370 via CPDLC. Anchorage Control, sector 11R, checked separation to a possibly conflicting Korean Airlines flight finding that at 21:26L the two flights would be 16nm apart again and thus cleared the flight to climb to FL370 by 05:30Z.

Shortly after receiving their clearance the China Airlines Boeing 747-400 began their climb and levelled off at FL370 at 05:20Z about 75nm westsouthwest of Attu Island.

The American Airlines Boeing 777-200 began their climb to FL370 at 05:30Z about 80nm northeast of Attu Island, the China Airlines 747 was about 40nm northnortheast of Attu Island at that time.

About a minute later the short term collision alert activated at the controller 11R's desk, the controller determined that at 05:33Z the distance between the aircraft would be 0.8nm only. He made blind transmissions to both aircraft but neither aircraft responded.

At 05:32:29Z China Airlines reported they were responding to a TCAS resolution advisory and were climbing. At 05:32:44Z the crew advised they were now clear of conflict and were descending back to FL370. Radar data show the aircraft reached FL375 during the climb.

At 05:33:26Z AA-183 complained on frequency that they had received clearance to climb to FL370, had been cleared to climb by 5:30Z, they did just that and received a TCAS resolution advisory with another aircraft. The controller replied: "American one eighty three roger, yup, that clearance should have been delayed."

Radar data taken from FAA's ASDI data show, AA-183 was at FL366 at 05:33:03Z already past the crossing point of the tracks, CI-5254 at FL375 at 05:33:04Z just before the crossing point, their horizontal distance had reduced to 0.68nm.

The NTSB is investigating the occurrence.