Chicago O-Hare Intl Airport
Aircraft Accident/Incident Report

Chicago, Illinois 60018
Friday, February 23, 2007 12:22 UTC

NTSB Narrative Summary Released at Completion of Accident

A flight attendant was seriously injured during an in-flight encounter with unforecast moderate to severe turbulence. The international air carrier flight was in cruise flight at the time of the accident. The captain stated the flight "encountered a brief (2-3 second) but very intense moderate-to-severe turbulence event" at flight level 340. He noted that continuous moderate turbulence continued for approximately 30 seconds, and periods of occasional-to-continuous moderate chop continued for about 10 minutes after the initial encounter. He added that there were no returns on the weather radar, and no pilot reports or adverse ride reports received from air traffic control. The fasten seat belt sign was on at the time of the encounter because the flight had encountered light chop after leveling off at cruise altitude. He reported that the ride had been smooth for approximately 10 minutes prior to the turbulence event. The injured flight attendant stated that she was working in the aft galley when the turbulence began. She reported that she hit her head on the ceiling and landed on the galley floor with her leg bent under her. The Flight Data Recorder (FDR) revealed that the airplane encountered a vertical acceleration ranging from 0.245 G to 1.246 G. The data also indicated that the autopilot was engaged, and no pitch inputs were made from the cockpit at the time of the encounter. Postaccident inspections did not reveal any damage to the airplane.

NTSB Probable Cause Narrative

An in-flight encounter with turbulence during cruise flight.

Event Information

Type of Event Accident
Event Date 2/23/2007
Event Day of the Week Friday
Time of Event 1222
Event Time Zone Coordinated Universal Time? Same as GMT
Event City Chicago
Event State ILLINOIS
Event Country --
Zipcode of the event site 60018
Event Date Year 2007
Event Date Month 2
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 415843N
Event Location Longitude 0875417W
Event Location Airport Chicago O-Hare Intl
Event Location Nearest Airport ID ORD
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness --
Investigator's weather source --
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
Lighting Conditions Night
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions --
Sky Condition for Lowest Ceiling --
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) --
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) --
Variable Wind Indicator --
Wind Speed (knots) --
Wind Velocity Indicator --
Wind Gust Indicator Unknown
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 103
Injury Total Serious 1
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 23012
NTSB Notification Source American Airlines
NTSB Notification Date Feb 24 2007 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Feb 28 2008 3:59PM
User who most recently changed record NTSB\johb
Basic weather conditions Visual Meteorological Cond
FAA District Office FAA-O'Hare FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N779AN
NTSB Number CHI07LA078
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed IFR
Flight plan Was Activated? Yes
Damage None
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Boeing
Aircraft Model 777
Aircraft Series Identifier --
Aircraft Serial Number 29955
Certified Max Gross Weight 648000
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft --
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection --
Airframe hours since last inspection --
Airframe Hours --
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name American Airlines Inc
Aircraft Owner Street Address --
Aircraft Owner City Fort Worth
Aircraft Owner State TX
Aircraft Owner Country USA
Aircraft Owner Zipcode --
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code AALA
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Scheduled
Indicates Domestic or International Flight International
Operator carrying Pax/Cargo/Mail Passenger Only
Type of Flying (Per_Bus / Primary) --
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code PVG
Departure City Shanghai
Departure State --
Departure Country CH
Departure Time 951
Departure Time Zone UTC
Destination Same as Local Flt --
Destination Airport Code ORD
Destination City Chicago
Destination State IL
Destination Country USA
Specific Phase of Flight Cruise
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 25 2008 1:36PM
User who most recently changed record SULP
Since inspection or accident --
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --