Boeing 777-224 accident near Sacramento, California, March 21, 2023
On March 21, 2023 at about 10:23 pm local time, a 1999 Boeing 777-224, registered N79011, was involved in an accident during enroute (climb to cruise) near Sacramento, California. It was flown under scheduled airline rules (Part 121). 1 person was seriously injured; 191 others were unhurt. The weather was visual conditions (good weather).
Preview. This page is not yet listed for search engines.
The NTSB's probable cause their words, unchanged
An encounter with forecast convective turbulence during climb.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 21, 2023 · about 10:23 pm local time
- Place
- Sacramento, California · map
- Type
- Accident
- Injuries
- 1 person was seriously injured; 191 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing 777-224, built 1999 · all 777-224s on the register
- Registration
- N79011 · registry record · serial 29859
- Damage
- Not recorded
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
United Airlines flight 194 encountered convective turbulence while climbing through 19,000 ft after departure from San Francisco International Airport (SFO), San Francisco, CA, and a flight attendant was seriously injured. Upon being notified of the injury, the flight crew declared an emergency and diverted to Denver, Colorado for medical assistance. The flight crew reported that before departure, the purser (lead flight attendant) was asked to have the flight attendants remain seated until the 10,000 ft signal due to weather conditions at the departure airport. After departure, airspeed fluctuations and turbulence were encountered with a smooth ride once the airplane was above a cloud layer. About 12,000 ft the captain gave the 10,000 ft signal that it was safe for the flight attendants to begin the initial service. When the flight was about 32 miles northeast of SFO the flight crew established communication with Oakland Air Route Traffic Control Center (ARTCC) while climbing through flight level (FL) 175 [17,500 ft]. The controller advised them to expect occasional light turbulence up to FL 260 and instructed them to climb to FL350. Shortly thereafter, as the airplane climbed through 19,000 ft, the flight encountered unexpected turbulence for about 5 seconds. The flight crew then received a call from the cabin advising them that a flight attendant had fractured her leg. At the time of the turbulence event, one of the flight attendants was in the aft galley preparing her cart for the initial service when she felt “violent up and down jolting turbulence”. She attempted to move towards the nearest jump seat when another “intense bump” occurred. She was thrown into the air and impacted the floor fracturing her leg. Airmen’s Meteorological Information (AIRMETs) were in effect at the time of the accident for moderate turbulence below 12,000 ft and moderate turbulence from FL220 to FL360. A convective Significant Meteorological Information (SIGMET) was issued at 1455 PDT and in effect at the time of the accident for the area with areas of thunderstorms forecast with tops to FL290. A convective SIGMET implies severe or greater turbulence, severe icing, and low-level windshear. Numerous pilot reports (PIREPs) reporting moderate or greater turbulence were issued for central California (including the accident area) within two hours of the accident time.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Turbulence encounter during enroute (climb to cruise) defining event
The NTSB's findings
- Environmental issues › Conditions/weather/phenomena › Turbulence › Convective turbulence › Effect on personnel
- Environmental issues › Conditions/weather/phenomena › Turbulence › Convective turbulence › Effect on operation
Pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 28,800 hours in all; 183 in this make and model; 183 in the last 90 days; 88 in the last 30 days; 10,600 as pilot in command; 1,500 on instruments
- Last flight review: December 12, 2022
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: left
- Injury: no injuries
Co-pilot
- Certificate: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instrument: airplane
- Flight time: 21,900 hours in all; 1,560 in this make and model; 77 in the last 90 days; 25 in the last 30 days; 3,850 as pilot in command; 2,550 on instruments
- Last flight review: September 30, 2022
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 101,792 hours
- Last inspection: continuous airworthiness programme, September 14, 2021
- Maximum gross weight: 622,061 lb
- Seats: 400
- Landing gear: retractable
- Engine 3: Ge GE90-90B (turbofan); 0 hours total
- Engine 4: Ge GE90-90B (turbofan); 0 hours total
- Operator: United Airlines INC
The flight
- Destination: Munich OF
- Flight plan: IFR
Weather at the time
- Light: daylight
- Wind: from 140° at 25 knots, gusting 38
- Visibility: 10 statute miles
- Sky: broken clouds at 6,000 ft; scat at 4,400 ft
- Temperature: 61°F (16°C), dew point 46°F (8°C)
- Altimeter: 29.34 inHg
- Observation at 3:27 pm from KSMF, 17 miles away
Weather report (METAR): SPECI KSMF 212227Z 14025G38KT 10SM SCT044 BKN060 16/08 A2934 RMK AO2 PK WND 14038/2227 WSHFT 2207 LTG DSNT SW AND W RAE00 TSE2157 P0000 T01560083
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flig | 1 | 11 | ||
| Passengers | 180 |
Other NTSB records under N79011 the same tail number, which may have belonged to a different aircraft at the time
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number DCA23LA213.