Boeing 747-422 N119UA

Summary

On 12 December 2000 at about 20:21 local time, a Boeing 747-422 registered N119UA was involved in an incident near Port Heiden, Alaska, United States. 390 people were on board and 4 had minor injuries. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

12 December 2000 at 20:21

Classification

Incident

Location

Port Heiden, Alaska, United States

Coordinates

56.9604, -158.5791

Aircraft

Boeing 747-422

Registration

N119UA

Category

Airplane

Engines

4

Operator

Not recorded

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

San Francisco → Hong Kong

Aircraft damage

Minor

Weather

VMC

Light

Dusk

NTSB number

ANC01IA022

4 people had minor injuries.

An encounter with severe turbulence while in cruise flight. Factors in the incident were a delay in notification of the turbulence, and the lack of controller/pilot data link communications in the Anchorage ARTCC area.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

A Boeing B-747 airplane departed San Francisco for Hong Kong. Prior to departure, no significant meteorological notices or forecasts for turbulence were issued for the area of the Alaska Peninsula, over which the flight would progress. The airplane was initially in radio and data link communications with Oakland ARTCC, then ARINC, and finally with Anchorage ARTCC. A PIREP at 1432 for moderate turbulence, and an Urgent PIREP at 1600 of severe turbulence, were recorded in the area of incident by Anchorage ARTCC. As the flight entered the Alaska ARTCC area, a delay in establishing communications with the airplane also delayed the transmission of the urgent PIREP concerning turbulence in the area of the flight. The crew noticed rolling clouds ahead of the airplane and advised the cabin flight attendants to be seated. At 1620, while in cruise flight at 31,000 feet, the airplane encountered moderate to severe turbulence. About 5 seconds after the notification to sit down, three cabin attendants were thrown to the floor of the airplane. The captain diverted the flight to Anchorage. Upon arrival at Anchorage, a belly mounted fuselage panel enclosing an air conditioning unit, was missing. Airplanes conducting oceanic flights are equipped with ACARS, over which flight crews can receive ATC clearances and weather data utilizing controller/pilot data link communications (CPDLC). The Anchorage ARTCC was not utilizing CPDLC because their software is not user friendly, requires substantial controller input for free text messaging, and is not as fast as voice communications. Hazardous inflight weather advisories are reviewed by each center weather coordinator, in conjunction with the National Weather Service for dissemination to pilots. The FAA does not a direct mechanism to alert air crews of significant weather in one sector, occurring in another sector, nor does the FAA have a mechanism to coordinate CPDLC data from an ARTCC sector to ARINC. A SIGMET for occasional turbulence was issued by the National Weather Service at 1619.

Quoted verbatim from the NTSB record.