# NTSB ANC01IA022: Boeing 747-422, N119UA, Port Heiden, AK, December 12, 2000 - Type: NTSB incident investigation - Classification: Incident · Minor injuries · Incident investigation · Final report - Date: December 12, 2000, 16:21 local (20:21 UTC) - Place: Port Heiden, AK - Coordinates: 56.960353, -158.579147 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=56.9604&lon=-158.5791&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 4 minor, 386 uninjured - Status: Completed, report November 1, 2001 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 51011 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC01IA022 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/51011/pdf - Page: https://openairdocs.org/ntsb/ANC01IA022 ## Probable cause 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. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, cruise - weather condition - turbulence,clear air (cause) - hazardous weather advisory - delayed, atc personnel(artcc) (contributing factor) - communications/information/atc - not used, atc personnel(artcc) (contributing factor) ## Analysis 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. ## Factual narrative HISTORY OF FLIGHT On December 12, 2000, about 1621 Alaska standard time, a Boeing 747-422 airplane, N119UA, sustained minor damage, about 75 miles south-southwest of Port Heiden, Alaska, about latitude 56 degrees, 00 minutes north, and longitude 160 degrees, 00 minutes west. While in cruise flight at 31,000 feet, the airplane encountered turbulence. The airplane was being operated as an instrument flight rules (IFR) scheduled international flight under Title 14, CFR Part 121, when the incident occurred. The airplane was operated as Flight 805 by United Airlines Inc., Elk Grove, Illinois. The captain, the first officer, and two reserve crew members were not injured. Three cabin attendants received minor injuries. Fifteen cabin attendants were not injured. One passenger received minor injuries, and 367 passengers were not injured. The flight originated at the San Francisco International Airport, San Francisco, California, about 1237 AST, with a destination of Hong Kong, China, but diverted to Anchorage, Alaska. In the narrative portion of the NTSB Pilot/Operator Report, the company reported the crew reviewed the company's weather briefing message provided with each flight plan. The message showed no SIGMETS or forecast turbulence along the route of flight. A chance of light to occasional moderate turbulence was reported from San Francisco to 130 degrees west longitude, within the first hour of the flight. One pilot report (PIREP) was noted over PUGGY intersection (about 50 miles north of St. Paul Island, at 57 degrees, 57.1 minute north and 170 degrees, 45.7 minutes west) at 32,000 feet, but the report was nine hours before the airplane's estimated time of arrival (ETA) into the incident area. The Pilot/Operator Report narrative noted that turbulence along the route of flight was typical, and the flight crews rely heavily on PIREPS for the most accurate and timely information. After departure from San Francisco, the Federal Aviation Administration (FAA) reported the incident flight crew was in radio contact with the Oakland Air Route Traffic Control Center (ARTCC). The flight was handed off to a San Francisco Aeronautical Radio Incorporated (ARINC) oceanic controller, who then had the flight crew contact Anchorage ARTCC controllers as the flight progressed over Alaska. When the airplane diverted to Anchorage, the National Transportation Safety Board (NTSB), investigator-in-charge (IIC), talked with the flight and cabin crew when the airplane arrived at the terminal. The captain reported that after departure from San Francisco, the flight progressed normally and they had switched to the Anchorage ARTCC radio frequency as the airplane entered the Anchorage ARTCC airspace. The captain said there was a delay in making radio contact with the Anchorage ARTCC, and when communication was established, the Anchorage center controller advised that there were reports of moderate to severe turbulence ahead of the airplane's flight path. A copy of the FAA's transcripts of radio communications with the incident airplane begins at 1603. A review of the transcripts revealed that at 1611:54, the Anchorage ARTCC sector R12 controller attempted to make radio contact with the incident airplane by stating, "and United 805, if you read center, you're probably out of range of my receivers, however this will be in the blind; United 805, moderate to severe turbulence reported crossing 56 (degrees) north, 160 (degrees) west, two minutes ago, and that was ah (flight level) 320 to 340, no reports lower." At 1618:54, the incident airplane checked on the ARTCC radio frequency, and the center controller said, "United 805, Anchorage center, how to you read." The crew of the airplane replied, "Loud and clear now sir, we're just ah about twenty miles east of ah 160 (degrees) west." The center controller confirmed the airplane was in radar contact and inquired if the crew heard the earlier report of turbulence. The crew responded that they did not. At 1619:14, the center controller stated, "Alright, an aircraft about thirty minutes ago now, crossing 56 (degrees) north, 160 (degrees) west, reported ah, moderate to severe turbulence at flight level ah 320 through flight level 340." The crew acknowledged the information. The captain said he observed rolling clouds ahead of the airplane's flight path. He slowed the aircraft, turned the "fasten seat belt" sign on, and advised the cabin crew of the reported turbulence. This was accomplished by contacting the flight attendant at door number 2 left (the L2 position), via the airplane intercom, advising the cabin crew to sit down. About 3 to 5 minutes after receiving the turbulence advisory, the airplane encountered the turbulence. The captain said the airplane shuddered, rolled about 15 degrees, and accelerated for about 10 to 15 seconds. He said the airplane did not encounter any pronounced vertical acceleration. At 1621:56, the incident airplane crew contacted the Anchorage ARTCC controller and stated, "Yes sir, we'll concur with that earlier report, it was ah moderate to severe turbulence over 160 (degrees) west, and ah smoothed out now, I don't know how long it'll last." Over the next several minutes, the crew requested altitude changes to reach smoother air, and they were given several radio frequency changes. At 1648:43, the crew contacted the Anchorage ARTCC Sector 11 controller and stated, "ah we'll tell you we've had ah an injury on board sir, and ah what we'd like to do is get a clearance back to ah Anchorage." The captain diverted the flight to the Ted Stevens Anchorage International Airport, Anchorage, Alaska, dumping fuel before arrival. During the flight to Anchorage, the crew of the airplane commented to the ARTCC controller that the turbulence encounter was severe, and was as bad as they had ever gone through. The crew also stated the turbulence encounter "...last(ed) about twenty seconds, twenty five seconds, ah Anchorage center had actually told as about it and I ah turn(ed) the seat belt sign on, had the people down, and told the flight attendants, but a couple of them didn't make it to the seat in time." INJURIES TO PERSONS One passenger received minor injuries, but did not require treatment. The injured cabin attendants were transported to a hospital in Anchorage. In interviews between the NTSB IIC and the cabin crew at the hospital, one cabin attendant said that she heard an "All CALL" from the L2 position to have flight attendants take their seats. She was attempting to sit in a jump seat at the rear of the airplane, next to door number 5R. About 5 seconds later, she reported being thrown to the floor, lost her right shoe, and injured her left ankle. Two cabin attendants were also moving toward seats next to door number 5L. One of the two cabin attendants reported hearing the "ALL CALL" to sit down. She said she tried to grab onto a passenger seat back, but ended up on the floor with back pain. She did not remember what she collided with. A duty-free cart, unsecured in the isle, and the second cabin attendant near door 5L, were thrown into the door 5L emergency slide cover. The second flight attendant was reported as having experienced severe back pain, but was unavailable for interview at the hospital. After a medical examination, United Airlines personnel at Anchorage reported that the cabin attendants received muscle strains, and bumps and bruises. They were released from the hospital without being admitted. DAMAGE TO AIRCRAFT After landing at the Ted Stevens Anchorage International Airport, the airplane was inspected for any damage. A portion of panel 192ER, part of an ram air exhaust panel, was missing. The honeycomb fuselage panel, about 36 inches by 65 inches, normally installed to enclose the number three air conditioning unit on the underside of the fuselage, was torn off the airplane. The forward edge of the panel is normal ## Aircraft - Registration: N119UA (not matched to a registry record) - Reported make and model: Boeing 747-422 - Category: Airplane - Serial number: 28812 - Airframe hours: 7949 - Engines: P&W PW4066 56000 lbs thrust turbo fan - Damage: Minor damage - Flight: Part 121 - Registered owner: United Airlines Inc. - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, November 20, 2000, 3 hours before - Departed: KSFO, SAN FRANCISCO, CA - Destination: VHHH, HONG KONG, OF - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; airline transport, flight engineer; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 18,453 total, 1,350 in this make and model ## Weather - Conditions: Visual (VMC), Dusk - Wind: 145° at 60 knots - Temperature: -65 °F - Altimeter: 29.00 inHg From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.