# NTSB CHI95IA204: McDonnell Douglas DC-10-10, N131AA, Green Bay, WI, June 27, 1995 - Type: NTSB incident investigation - Classification: Incident · Minor injuries · Incident investigation · Final report - Date: June 26, 1995, 20:00 local (Jun 27, 1995, 01:00 UTC) - Place: Green Bay, WI - Coordinates: 44.540622, -88.049522 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.5406&lon=-88.0495&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 17 minor, 100 uninjured - Status: Completed, report July 17, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 9765 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI95IA204 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9765/pdf - Page: https://openairdocs.org/ntsb/CHI95IA204 ## Probable cause the weather condition (turbulence in clouds). A factor was the flight crew's abrupt control of the airplane. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, cruise - weather condition - turbulence in clouds (cause) - aircraft control - abrupt, flightcrew (contributing factor) ## Analysis While in level flight at 37,000 feet in cirrus clouds, the airplane encountered moderate to severe turbulence. The airplane was on autopilot and seat belt signs were off. The flight crew took abrupt action to control the airplane with control inputs. No damage was reported to the airplane; however 17 persons on board the airplane reported minor injuries. ## Factual narrative HISTORY OF FLIGHT On June 26, 1995, about 2000 central daylight time, American Airlines Flight 58, a McDonnell Douglas DC-10-10, N131AA, encountered turbulence while in cruise flight at 37,000 feet, near Green Bay, Wisconsin. The flight departed Los Angeles, California, at 1400 pacific standard time with the intended destination of Jamaica, New York. The crew diverted the flight to Chicago, Illinois, where the airplane landed uneventfully at 2046 central daylight time. Subsequently 13 passengers and 3 flight attendants were transported to local hospitals for examination and treatment for minor injuries. There were a total of 103 passengers, 3 flight crew and 11 flight attendants aboard the airplane on departure from Los Angeles. The flight crew reported that they were flying at flight level 370, twenty-five miles west of Gopher VOR, in thin cirrus clouds. The seat belt signs were off, and the radar reported no echoes, when the airplane encountered five to eight seconds of moderate to severe turbulence. They reported rapid vertical movement with a maximum altitude increase of 200 feet, with the autopilot on. Both pilots said they took control to maintain level flight. After the turbulence encounter it became smooth again. They reported that they then began to assess injuries and made the decision to divert to O'Hare Airport, Chicago, Illinois. FLIGHT RECORDERS The flight data recorder information was analyzed by the Office of Research and Engineering, Vehicle Performance Division of the NTSB. That report is attached as an addendum to this report. The report indicated that, "At (the request of the NTSB), American Airlines provided a (flight data recorder} readout of the event. The data were subsequently sent to McDonnell Douglas for further evaluation. (McDonnell Douglas) developed a vertical wind time history for use in their simulator. The elevator deflection and vertical wind time histories resulted in a simulated load factor time history that was similar to that recorded on the FDR (graph II, [attached]). When the elevator was held constant, the wind time history produced the load factor data seen in graph IV, (attached). According to the graphs, if the elevator had not been moved, the load factor would have decreased to near zero as a result of the wind flow field. Therefore, the elevator deflection resulted in the load factor decreasing to the -0.5 G range." ADDITIONAL INFORMATION The Federal Aviation Administration, Flight Standards District Office, Schiller Park, Illinois, was party to the investigation. ## Aircraft - Registration: N131AA (not matched to a registry record) - Reported make and model: McDonnell Douglas DC-10-10 - Category: Airplane - Serial number: 46994 - Airframe hours: 52359 - Engines: GE CF-6-6 turbo fan - Damage: No damage - Flight: Part 121 - Registered owner: American Airlines, Inc. - Airworthiness certificate: Standard, Transport - Departed: LAX, LOS ANGELES, CA - Destination: JFK, JAMAICA, NY - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; airline transport, flight engineer; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 7,589 total, 7,051 in this make and model, 2,644 as pilot in command ## Weather - Conditions: Visual (VMC), Dusk - Wind: 180° at 14 knots - Visibility: 5 statute miles - 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). - [Incident 19950626021809I](https://openairdocs.org/incident/19950626021809I), Jun 26, 1995: Doug DC1010, Chicago, IL. At FL370 encountered cat. Seat belt sight off. Passengers and flight attendents minor injuries. 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.