# NTSB CHI05LA135: Boeing 757-223, N602AN, New Chicago, IN, June 5, 2005 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: June 5, 2005, 13:00 local (18:00 UTC) - Place: New Chicago, IN - Coordinates: 41.560001, -87.274444 - Nearby events: https://openairdocs.org/map.md?lat=41.5600&lon=-87.2744&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor, 160 uninjured - Status: Completed, report March 28, 2006 - Report: Approved by Office Director - Parties: American Airlines, Inc. - NTSB case key (mKey): 61726 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI05LA135 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61726/pdf - Page: https://openairdocs.org/ntsb/CHI05LA135 ## Probable cause The inadvertent encounter with convectively induced turbulence (CIT) while the aircraft was descending into the terminal area. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, descent - normal - weather condition - turbulence in clouds (cause) ## Analysis During cruise descent the airplane encountered convectively induced turbulence (CIT) and two flight attendants were injured. One of the injured flight attendants was located in the aft galley preparing for landing when the airplane encountered the turbulence. The flight attendant stated that she heard the captain say "prepare for landing" and "all of [a] sudden I got lifted off the ground and slammed into the 4R door." This flight attendant suffered a fractured ankle. The other injured flight attendant was located near the aft lavatories preparing for landing when the airplane encountered the turbulence. The flight attendant stated that the airplane "hit some type of severe turbulence without warning" and that she was "thrown to the floor." This flight attendant suffered minor injuries to her shoulder, hip, foot, and lower back. Data from the airplane's Digital Flight Data Recorder (DFDR) was extracted and indicated that the airplane experienced vertical accelerations that were consistent with a CIT event. During the approximately 4 second CIT encounter, the maximum and minimum vertical accelerations were about 1.9g and 0.5g, respectively. ## Factual narrative On June 5, 2005, around 1300 central daylight time (cdt), a Boeing 757-223, N602AN, operated by American Airlines as Flight 1399, encountered moderate turbulence while descending through 13,000 feet mean sea level (msl) near BEARZ intersection, New Chicago, Indiana. Instrument meteorological conditions prevailed at altitude. The commercial flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 121. One flight attendant was seriously injured and another flight attendant sustained minor injuries. The captain, first officer, 2 remaining flight attendants, and 156 passengers were not injured. The flight departed Miami International Airport (MIA) at 1124 eastern daylight time (edt) and arrived at Chicago O'Hare International Airport (ORD) at 1320 cdt. The captain reported that as the airplane approached the BEARZ intersection he noticed a developing line of clouds with cloud tops ranging between 15,000 and 18,000 feet msl. The captain stated that he believed that the remainder of the flight "might be bumpy, but not excessively so, because of a lack of bad ride reports from other aircraft passing through the same area and the low altitude of the clouds." The captain reported that five to eight minutes before encountering the turbulence he made a public announcement and told the flight attendants to prepare for landing. The captain stated that the airplane encountered "moderate turbulence" while descending in the clouds. The captain reported that after clearing the clouds the "ride smoothed out" and he called the flight attendants and was told that two flight attendants were injured and were being treated by physicians. The captain requested that paramedics meet the airplane after landing. The flight attendant who was seriously injured was located in the aft galley preparing for landing when the airplane encountered the turbulence. The flight attendant stated that she heard the captain say "prepare for landing" and "all of [a] sudden I got lifted off the ground and slammed into the 4R door." This flight attendant suffered a fractured ankle. The flight attendant who sustained minor injures was located near the aft lavatories preparing for landing when the airplane encountered the turbulence. The flight attendant stated that the airplane "hit some type of severe turbulence without warning" and that she was "thrown to the floor." This flight attendant suffered minor injuries to her shoulder, hip, foot, and lower back. She elected to complete the remainder of her scheduled flights. Data from the airplane's Digital Flight Data Recorder (DFDR) was extracted and indicated that the airplane experienced vertical accelerations that were consistent with a convectively induced turbulence (CIT) event. The CIT encounter was recorded at 1259:42 (hhmm:ss) and lasted about 4 seconds. During the CIT encounter, the maximum and minimum vertical accelerations were about 1.9g and 0.5g, respectively. ## Aircraft - Registration: [N602AN](https://openairdocs.org/deregistered/N602AN-2021-11-16), registration cancelled 2021-11-16, S/N 27053, built 1995 (OpenAirDocs) - Reported make and model: Boeing 757-223 - Registry model: [Boeing 757-223](https://openairdocs.org/model/boeing-757-223) (registry code 1384957) (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: 27053 - Airframe hours: 33715 - Engines: Rolls-Royce RB211-63 turbo fan; Rolls-Royce RB211-63 turbo fan - Damage: No damage - Flight: Part 121 - Registered owner: American Airlines, Inc. - Airworthiness certificate: Standard, Transport - Last inspection: AAIP, June 1, 2005 - Departed: MIA, Miami, FL - Destination: ORD, Chicago, IL - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review February 1, 2005; seat: left; flight hours: 16,000 total, 5,500 in this make and model, 4,800 as pilot in command - Co-pilot; age 34; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review April 1, 2005; seat: rear; flight hours: 1,200 total, 1,100 in this make and model, 2,500 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 8 knots, gusting 20 - Visibility: 10 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 91 °F, dew point 72 °F - Altimeter: 29.76 inHg - Observed at: GYY ## 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 20050605024489A](https://openairdocs.org/incident/20050605024489A), Jun 5, 2005: Boeing 757223, New Chicago, IN. (-23) On June 5, 2005, around 1300 central daylight time (CDT), a Boeing 757-223, N602AN, operated by American airlines as flight 1399, encountered moderate… 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.