# NTSB LAX94LA141: Boeing 747-400, N186UA, Pacific Ocean (Pacific Ocean), February 12, 1994 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: February 12, 1994 - Place: Pacific Ocean (Pacific Ocean) - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 408 uninjured - Status: Completed, report November 14, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 28679 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX94LA141 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28679/pdf - Page: https://openairdocs.org/ntsb/LAX94LA141 ## Probable cause the failure of the chief steward to verify that all flight attendants had been informed, and were complying with the captain's instructions to remain seated with their seatbelts fastened. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, cruise - normal - weather condition - turbulence,clear air (contributing factor) - instructions,written/verbal - not issued, other crewmember (cause) - Miscellaneous/other, cruise - normal - seat belt - not used, flight attendant (cause) ## Analysis The airliner was on an authorized off-course deviation, approaching MEGOG intersection, to circumvent some convective activity which had been identified on radar. As a precaution, the 'fasten seatbelt' light was illuminated and the captain told the chief purser to advise the other flight attendants of possible turbulence and to be seated. Approximately ten minutes later at MEGOG intersection, the aircraft encountered three to five seconds of what the captain described as moderate-to-severe turbulence. The weather radar was on at the time of the of the actual encounter; however, there were no weather returns showing on the scope. During the turbulence, one flight attendant who did not get the prewarning was answering a passenger call, and was not seated. Passenger reports indicate that, at the onset, the flight attendant left the floor of the aircraft and came back down hard on her shoulder and side. It was later determined that the flight attendant suffered a hairline fracture of the right clavicle. ## Factual narrative On February 12, 1994, about 1345 coordinated universal time, a Boeing 747-400, N186UA, encountered clear air turbulence at flight level FL350 while in cruise over the Pacific Ocean at a position W 157.00 by S 010.03.4. During the encounter, one of the flight attendants fell, sustaining a fractured right clavicle. The aircraft was operated by United Airlines, Inc., as flight 841, a scheduled international passenger flight from Los Angeles, California, to Auckland, New Zealand, under the provisions of 14 CFR Part 121 of the Federal Aviation Regulations. The aircraft was not damaged. One flight attendant sustained serious injuries; however, the remaining 408 passengers and crewmembers were not injured. The flight originated at Los Angeles, California, on the day of the mishap at 0626 Pacific standard time as a nonstop flight to New Zealand. According to United Airlines, the aircraft was on an authorized off-course deviation, approaching MEGOG intersection, to circumvent some convective activity which had been identified on radar. As a precaution, the "fasten seatbelt" light was illuminated and the captain told the chief purser to advise the other flight attendants of possible turbulence and to be seated. Approximately ten minutes later at MEGOG intersection, the aircraft encountered three to five seconds of what the captain described as moderate-to-severe turbulence. The weather radar was on at the time of the actual encounter; however, there were no weather returns showing on the scope. During the turbulence, one flight attendant who did not get the prewarning was answering a passenger call, and was not seated. Passenger reports indicate that, at the onset the flight, attendant left the floor of the aircraft and came back down hard on her shoulder and side. It was later determined that the flight attendant suffered a hairline fracture of the right clavicle. ## Aircraft - Registration: [N186UA](https://openairdocs.org/deregistered/N186UA-2005-04-07), registration cancelled 2005-04-07, S/N 26875, built 1992 (OpenAirDocs) - Reported make and model: BOEING 747-400 - Registry model: [Boeing 747-422](https://openairdocs.org/model/boeing-747-422) (registry code 1384935) (OpenAirDocs) - Registry engine: [Pratt & Whitney PW4000 series](https://openairdocs.org/engine/pratt-whitney-pw4000-series) (registry code 52119, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 26875 - Airframe hours: 5917 - Engines: P&W PW4056 56000 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Operator: United Airlines - Registered owner: United Airlines - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, November 17, 1993, 1,265 hours before - Departed: LAX, LOS ANGELES, CA - Destination: PAKL, AUCKLAND - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; commercial, airline transport, flight engineer; airplane ratings: multi-engine land, single-engine sea, single-engine land; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 15,397 total, 1,110 in this make and model ## Weather - Conditions: Visual (VMC), Night/dark ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19940212014219A](https://openairdocs.org/incident/19940212014219A), Feb 12, 1994: Boeing 747422, Pacific Ocean, CA. While deviating around thunderstorms severe turbulence encountered causing serious injury to flight attendant. 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.