# NTSB CEN10LA240: Boeing 767, N320AA, Fort Dodge, IA, April 30, 2010 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: April 29, 2010, 21:40 local (Apr 30, 2010, 02:40 UTC) - Place: Fort Dodge, IA - Coordinates: 42.500896, -94.170417 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.5009&lon=-94.1704&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390) - Highest injury: Serious injuries - Injuries: 1 serious, 5 minor, 172 uninjured - Status: Completed, report April 12, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: American Airlines, Federal Aviation Administration - NTSB case key (mKey): 75952 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10LA240 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/75952/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=75952 - Page: https://openairdocs.org/ntsb/CEN10LA240 ## Probable cause The flight crew's inadequate separation from convective activity that resulted in serious injury to an unrestrained flight attendant. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Convective weather: thunderstorm](https://openairdocs.org/ntsb-findings/03033010): Environmental issues › Conditions/weather/phenomena · Effect on personnel (probable cause); cases with it: [Boeing 767-223, 1 case](https://openairdocs.org/ntsb-findings/03033010/cases.md?model=1385123), [All aircraft, 100 cases](https://openairdocs.org/ntsb-findings/03033010/cases.md) - [Turbulence: convective turbulence](https://openairdocs.org/ntsb-findings/03032020): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Boeing 767-223, 1 case](https://openairdocs.org/ntsb-findings/03032020/cases.md?model=1385123), [All aircraft, 145 cases](https://openairdocs.org/ntsb-findings/03032020/cases.md) - [Performance/control parameters: heading/course](https://openairdocs.org/ntsb-findings/01062047): Aircraft › Aircraft oper/perf/capability · Not specified (probable cause); cases with it: [Boeing 767-223, 1 case](https://openairdocs.org/ntsb-findings/01062047/cases.md?model=1385123), [All aircraft, 82 cases](https://openairdocs.org/ntsb-findings/01062047/cases.md) - [Equipment/furnishings: passenger compartment equip](https://openairdocs.org/ntsb-findings/01022520): Aircraft › Aircraft systems · Not used/operated (probable cause); cases with it: [Boeing 767-223, 1 case](https://openairdocs.org/ntsb-findings/01022520/cases.md?model=1385123), [All aircraft, 24 cases](https://openairdocs.org/ntsb-findings/01022520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390) (defining event); cases with it: [Boeing 767-223, 1 case](https://openairdocs.org/ntsb-events/390/sequence.md?model=1385123), [All aircraft, 224 cases](https://openairdocs.org/ntsb-events/390/sequence.md) - [Enroute-cruise: Turbulence encounter](https://openairdocs.org/ntsb-events/360); cases with it: [Boeing 767-223, 1 case](https://openairdocs.org/ntsb-events/360/sequence.md?model=1385123), [All aircraft, 423 cases](https://openairdocs.org/ntsb-events/360/sequence.md) ## Analysis The scheduled domestic passenger flight encountered turbulence while diverting around an area of convective activity. A flight attendant who was not seated sustained serious injuries and five others on board sustained minor injuries as a result of the turbulence encounter. Flight data recorder information showed that the airplane experienced a vertical acceleration from 0.5 and 2 g’s and an altitude change of 100 feet in each direction. ## Factual narrative On April 29, 2010, at 2140 central daylight time, a Boeing 767-223, N320AA, operated by American Airlines as flight 20, encountered turbulence during cruise flight near Fort Dodge (FOD), Iowa. Visual meteorological conditions prevailed at the time of the accident. Of the 178 people aboard, 1 flight attendant sustained serious injuries, 2 flight attendants sustained minor injuries, and 3 passengers sustained minor injuries. The 14 CFR Part 121 scheduled domestic passenger flight departed San Francisco International Airport, San Francisco, California, and was en route to John F. Kennedy International Airport, New York, New York. The flight diverted to Chicago O'Hare International Airport, Chicago, Illinois, and landed without further incident. The captain stated that the seat belt sign was on for about 20 minutes, and the flight attendants were instructed to secure the cabin and to take a seat 10-15 minutes prior to when they encountered moderate turbulence. The turbulence lasted for 3-5 seconds in the area of FOD while deviating upwind around and over a build-up. The first officer reported that the seatbelt sign was on and had been on for “some” time. There had been light chop but no reports of moderate chop or turbulence. They encountered moderate turbulence when they were on an upwind vector around a thunderstorm. After the turbulence encounter, the first officer received a report that one flight attendant injured her ankle and another flight attendant injured his hip. The number three flight attendant was standing aft looking into the main cabin after food service had just been completed when the airplane banked to the left and threw the flight attendants off balance. There was a sound during the roll of either wind or an engine. The airplane then seemed to move back to the right, but dropped while completing its level off. The number eight flight attendant, who was standing next to the number three flight attendant, hit the ceiling and then the floor with another flight attendant. The number three flight attendant thought she fractured her foot when she landed on the number eight flight attendant. According to the flight data recording for the flight, the airplane was at an altitude of approximately 41,000 feet at an airspeed of approximately 232 knots with the autopilot engaged. At the time of the event, the vertical accelerations fluctuated between -0.5 and 2 g’s, the longitudinal accelerations were between -0.1 and 0.1 g’s, and the lateral accelerations spiked as high as 0.2 g’s and as low as -0.1 g’s. The airplane rose and fell approximately 100 feet in each direction and the airplane rolled as far right as 20 degrees. There was no sudden change in wind direction or air pressure before the event. During the event, total air pressure spiked up to 300 mb from 270 mb. Wind direction changed to approximately 20 degrees further left during the event, but that can be accounted for by aircraft heading, which changed 20 degrees to the rightbefore the event. The cockpit voice recorder was reported as not having been deactivated following the accident and no recording for the accident flight was available to the National Transportation Safety Board. ## Aircraft - Registration: [N320AA](https://openairdocs.org/deregistered/N320AA-2015-03-25), registration cancelled 2015-03-25, S/N 22321, built 1985 (OpenAirDocs) - Reported make and model: BOEING 767 (223) - Registry model: [Boeing 767-223](https://openairdocs.org/model/boeing-767-223) (registry code 1385123) (OpenAirDocs) - Registry engine: [GE CF6-80 series](https://openairdocs.org/engine/ge-cf6-80-series) (registry code 30025, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 22321 - Airframe hours: 94084 - Engines: General Electric CF6/80A 61500 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Operator: American Airlines - Registered owner: US Bank NA Trustee - Airworthiness certificate: Standard, Transport - Departed: SFO, San Francisco, CA - Destination: JFK, New York City, NY - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review September 16, 2009; seat: left; flight hours: 2,501 in this make and model, 148 in the last 90 days, 42 in the last 30 days, 6 in the last 24 hours - Co-pilot; age 54; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review December 11, 2009; seat: right; flight hours: 2,502 in this make and model, 111 in the last 90 days, 42 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Night - Wind: 150° at 11 knots, gusting 17 - Visibility: 5 statute miles - Lowest ceiling: 500 ft overcast - Temperature: 55 °F, dew point 54 °F - Altimeter: 29.97 inHg - Observed at: FOD ## 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 20100429049119A](https://openairdocs.org/incident/20100429049119A), Apr 29, 2010: Boeing 767-223, Fort Dodge, IA, No damage. On April 29, 2010, at 210 central daylight time, a Boeing 767-223, N320AA, operated by American airlines as flight 20, encountered turbulence during cruise… ## Docket (7 files) The files NTSB released with the investigation on December 15, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=75952. 6.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 525 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40338666&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Crew Statements (item 2, .PDF, 271 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40338667&FileExtension=.PDF&FileName=Crew%20Statements-Master.PDF - Flight Data Recorder 10 - Specialist's Factual Report (item 3, .PDF, 612 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40335147&FileExtension=.PDF&FileName=Flight%20Data%20Recorder%2010%20-%20Specialist%27s%20Factual%20Report-Master.PDF - Flight Data Recorder 10 - Attachment 1: Tabular Data (item 4, ZIP, 3.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40335148&FileExtension=zip&FileName=Flight%20Data%20Recorder%2010%20-%20Attachment%201%3A%20Tabular%20Data-Master - ATC Report (item 5, .PDF, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40338665&FileExtension=.PDF&FileName=ATC%20Report-Master.PDF - Weather Reports - FOD ASOS (item 6, .PDF, 43 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40338668&FileExtension=.PDF&FileName=Weather%20Reports%20-%20FOD%20ASOS-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 7, .PDF, 56 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40338669&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF 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.