# NTSB SEA96LA026: Boeing 737-522, N953UA, Portland, OR, November 25, 1995 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: November 25, 1995, 15:23 local (23:23 UTC) - Place: Portland, OR - Coordinates: 45.580543, -122.910835 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.5805&lon=-122.9108&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 111 uninjured - Status: Completed, report July 25, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 42315 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA96LA026 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42315/pdf - Page: https://openairdocs.org/ntsb/SEA96LA026 ## Probable cause AN UNEXPECTED ENCOUNTER WITH UNFORECAST MODERATE HIGH LEVEL WINDSHEAR AND TURBULENCE AS THE FLIGHT ATTENDANT WAS PERFORMING HIS DUTIES DURING DESCENT. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, descent - normal - weather condition - windshear (cause) - weather condition - turbulence (cause) - seat belt - not used, flight attendant (cause) ## Analysis THE CAPTAIN REPORTED THAT AT THE BEGINNING OF THE DESCENT FOR LANDING HE TURNED ON THE SEATBELT SIGN AND INFORMED THE CABIN CREW TO SECURE THE CABIN EARLY BECAUSE OF SUSPECTED TURBULENCE. HE DID NOT URGE THE FLIGHT ATTENDANTS TO BE SEATED IMMEDIATELY, BECAUSE NONE OF THE WEATHER INFORMATION HE RECEIVED AT THE TIME INDICATED ANYTHING OTHER THAN THE POSSIBILITY OF LIGHT TURBULENCE. ABOUT 15 MINUTES LATER, WHILE DESCENDING THROUGH FLIGHT LEVEL 200, THE AIRPLANE BRIEFLY ENCOUNTERED WHAT THE CAPTAIN DESCRIBED AS MODERATE TURBULENCE. ONE OF THE FLIGHT ATTENDANTS WAS STILL SECURING THE CABIN AT THE TIME AND FELL BACKWARDS ONTO A STOVE IN THE GALLEY, SUSTAINING A FRACTURED SHOULDER. WEATHER INFORMATION RECEIVED AFTER THE ACCIDENT REVEALED THAT MODERATE TURBULENCE OR SIGNIFICANT WEATHER REPORTS WERE NOT FORECAST FOR THE ALTITUDE OF OCCURRENCE BY THE NATIONAL WEATHER SERVICE. ## Factual narrative On November 25, 1995, at 1523 hours Pacific standard time, N953UA, a Boeing 737-522, operated as United Airlines Flight 2026, encountered turbulence while descending for landing at the Portland International Airport, Portland, Oregon. A cabin crew member was seriously injured during the encounter. The other four crew members and 107 passengers were not injured. The airplane was not damaged. Instrument meteorological conditions prevailed and an instrument flight rules flight plan had been filed. The flight departed San Francisco, California, at 1409 and was en route to Portland. The flight was operated under 14 CFR 121. In a written statement, the captain reported that at the beginning of the descent from 28,000 feet above mean sea level (msl), he turned on the seatbelt sign and informed the cabin crew "... that there might be some chop in [descent] and to put things away early." The captain reported that the airplane then encountered "moderate turbulence lasting approximately 15 [seconds]." The captain immediately informed the flight attendants to be seated. While securing the cabin at the time of the turbulent encounter, one of the flight attendants fell backwards onto a stove in the galley and fractured his scapula. Another flight attendant, who was in the aisle, reported that she grabbed the back of a passenger seat and immediately sat down on the aisle. Nearby passengers held onto the flight attendant so that she would not be thrown around. The captain further stated that "no [turbulence was] reported other than [light] chop" prior to the accident. No evidence was found from either the captain's statement or flight attendants' statements to indicate that the captain urged the flight attendants to immediately take their seats prior to the turbulent encounter. According to documentation provided by United Airlines personnel, other aircraft reported, via the Aircraft Communication Addressing and Reporting System (ACARS), that during the climb and descent phase, there was significant wind shears between 20,000 feet msl to 28,000 feet msl near the time of the accident. The National Weather Service high level significant weather chart forecasted moderate turbulence between 30,000 feet msl to 37,000 feet msl over Oregon. ## Aircraft - Registration: [N953UA](https://openairdocs.org/deregistered/N953UA-2005-05-19), registration cancelled 2005-05-19, S/N 26700, built 1993 (OpenAirDocs) - Reported make and model: Boeing 737-522 - Registry model: [Boeing 737-522](https://openairdocs.org/model/boeing-737-522) (registry code 138449F) (OpenAirDocs) - Registry engine: [CFM International CFM56 series](https://openairdocs.org/engine/cfm-international-cfm56-series) (registry code 13802, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 26700 - Airframe hours: 7220 - Engines: Cfm CFM56-36-1 20000 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Operator: United Airlines, Inc., doing business as United Airlines - Registered owner: Wilmington Trust Co. - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, November 6, 1995, 149 hours before - Departed: SFO, SAN FRANCISCO, CA - Destination: PDX, OR - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; commercial, flight engineer, airline transport; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 5,430 total, 527 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 110° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 4,500 ft broken - Temperature: 50 °F, dew point 46 °F - Altimeter: 29.00 inHg ## 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 19951125039519A](https://openairdocs.org/incident/19951125039519A), Nov 25, 1995: Boeing 737522, Portland, OR. Encountered turbulence during descent. Attendant injured. Seat sign on attendants warned. 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.