# NTSB CHI00LA268: Boeing 777-223, N785AN, Baraboo, WI, August 22, 2000 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: August 22, 2000, 14:10 local (19:10 UTC) - Place: Baraboo, WI - Coordinates: 43.459369, -89.74047 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.4594&lon=-89.7405&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 250 uninjured - Status: Completed, report December 18, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 50076 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI00LA268 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/50076/pdf - Page: https://openairdocs.org/ntsb/CHI00LA268 ## Probable cause the unexpected turbulence encountered by the airplane. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Miscellaneous/other, descent - normal - weather condition - turbulence (cause) ## Analysis A flight attendant received a broken bone in her foot when the airplane unexpectedly encountered turbulence. The flight was between FL260 and FL240 in a descent to FL190 and the seat belt sign was on when the turbulence was encountered. The captain reported they were in instrument meteorological conditions and the radar was indicating cells to the west of their course, but not along their flight path. He reported there was a downdraft followed by an updraft and that the bank angles did not exceed 30 degrees. The first officer reported the radar was indicating only light precipitation in the area of the encounter. ## Factual narrative On August 22, 2000, at approximately 1410 central daylight time, N785AN, a Boeing 777-223 operated by American Airlines as flight 154, encountered unexpected turbulence, while descending from FL260 to FL190 near the DELLS (DLL) VORTAC in Baraboo, Wisconsin. One flight attendant was seriously injured. The 4 cockpit crewmembers, 11 additional flight attendants, and 235 passengers were not injured. The airplane was not damaged. The 14 CFR Part 121 flight was operating in instrument meteorological conditions at the time of the encounter and the flight was on an IFR flight plan. The flight originated from the Narita Airport, Tokyo, Japan, and continued on to its intended destination of Chicago, Illinois, where it landed without incident. The captain reported the seatbelt sign was on when they encountered unexpected moderate to severe turbulence. He reported they were in instrument meteorological conditions and the radar was indicating cells to the west of their course, but not along their flight path. He reported there was a downdraft followed by an updraft and that the bank angles did not exceed 30 degrees. The first officer reported they were about 20 miles northwest of the DLL VORTAC between FL260 and FL240 when the turbulence was encountered. He reported, "Both the Captain and I had our radar on. My radar indicated nothing other than light precipitation between our position and the VOR. We first encountered what I would term as moderate turbulence. It quickly got worse. I notified ATC of the turbulence as the Captain continued to fly the airplane. A flight attendant opened the cockpit door to inform us that one flight attendant had been injured." Both relief first officers were in the back of the airplane when the turbulence was encountered. They both reported that they were thrown to the floor at the time. One of the relief first officers reported, "The seat belt sign was on and all passengers were seated. The flight attendants were preparing the cabin for landing. The #11 flight attendant apparently injured her foot. I and another flight attendant secured the #11 flight attendant to a jump seat and put an ice pack on her foot. I instructed all other flight attendants to remain in their seats. I returned to the cockpit, and the Captain made the prepare for landing P.A. and reminded everybody to remain seated." The flight attendant who was injured sustained a fractured cuneiform bone in her foot. ## Aircraft - Registration: [N785AN](https://openairdocs.org/aircraft/N785AN), registered now, S/N 30005, built 2000 (OpenAirDocs) - Reported make and model: Boeing 777-223 - Registry model: [Boeing 777-223](https://openairdocs.org/model/boeing-777-223) (registry code 1385213) (OpenAirDocs) - Registry engine: [Rolls-Royce RB-211 series](https://openairdocs.org/engine/rolls-royce-rb-211-series) (registry code 54555, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 30005 - Airframe hours: 1655 - Engines: Rolls-Royce TRENT 892 turbo jet - Damage: No damage - Flight: Part 121 - Registered owner: American Airlines, Inc. - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, August 19, 2000, 47 hours before - Departed: NRT, TOKYO, OF - Destination: ORD, CHICAGO, IL - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; flight engineer, airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left ## Weather - Conditions: Instrument (IMC), Day - Wind: 230° at 5 knots - Visibility: 2.5 statute miles - Lowest ceiling: 1,900 ft broken - Temperature: 163 °F, dew point 162 °F - Altimeter: 30.00 inHg - Observed at: MSN, 30 nm away ## 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 20000822043129A](https://openairdocs.org/incident/20000822043129A), Aug 22, 2000: Boeing 777223, Chicago, IL. (-23) [privacy data omitted] American airlines flt. 154 from narita, japan (nrt) hit unexpected turbulence in descending from FL 260 to FL 240. Over southwest… 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.