# NTSB LAX97LA112: Boeing 767-300, N661UA, San Francisco, CA, February 25, 1997

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: February 25, 1997, 13:09 local (21:09 UTC)
- Place: San Francisco, CA
- Coordinates: 37.559085, -122.369812 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.5591&lon=-122.3698&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 109 uninjured
- Status: Completed, report May 30, 1997
- Report: Approved by Office Director
- NTSB case key (mKey): 29732
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX97LA112
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29732/pdf
- Page: https://openairdocs.org/ntsb/LAX97LA112

## Probable cause

an encounter with unforecasted moderate clear air turbulence, while descending over mountainous terrain.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- In flight encounter with weather, descent - normal
  - terrain condition - mountainous/hilly
  - weather condition - turbulence,clear air (cause)

## Analysis

A flight attendant sustained a serious injury after the aircraft experienced a single, severe jolt of unforecasted moderate clear air turbulence during the descent over mountainous terrain. The seat belt sign was not illuminated at the time.

## Factual narrative

On February 25, 1997, at 1309 hours Pacific standard time, a flight attendant received a serious injury during an encounter with clear air turbulence over the Sierra mountains while the aircraft was in a descent to San Francisco, California.  Visual meteorological conditions existed at the time.  The aircraft, a Boeing 767-300, N661UA, was operated by United Airlines as flight 961 from Paris, France, with a total of 110 people onboard.  None of the other people onboard were injured.

According to United Airlines, the aircraft was descending through flight level 330 when the aircraft experienced a single, severe jolt of unforecasted moderate clear air turbulence.  The aft flight attendant, working in the rear galley, fractured her right ankle that later required surgery.  The fasten seat belt sign was not illuminated at the time.

## Aircraft

- Registration: [N661UA](https://openairdocs.org/aircraft/N661UA), registered now, S/N 27158, built 1993 (OpenAirDocs)
- Reported make and model: Boeing 767-300
- Registry model: [Boeing 767-322](https://openairdocs.org/model/boeing-767-322) (registry code 1385200) (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: 27158
- Airframe hours: 16622
- Engines: P&W PW4060 38200 lbs thrust turbo fan
- Damage: No damage
- Flight: Part 121
- Registered owner: United Airlines
- Airworthiness certificate: Standard, Transport
- Last inspection: Continuous airworthiness, January 23, 1997, 480 hours before
- Departed: CDG, PARIS
- Destination: SFO
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 49; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 11,644 total, 793 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Lowest ceiling: none
- 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 19970225019939A](https://openairdocs.org/incident/19970225019939A), Feb 25, 1997: Boeing 767322, San Francisco, CA. (.4)A flight attendant sustained a serious injury after the aircraft experienced a single, severe jolt of unforecasted moderate clear air turbulence during the…

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.

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