Aircraft Accident/Incident Report

Springfield, Missouri 65721
Thursday, April 18, 2002 16:35 CDT

NTSB Narrative Summary Released at Completion of Accident

The air carrier passenger flight encountered severe turbulence while in cruise flight. Three passengers were seriously injured and nine passengers and three flight attendants received minor injuries during the turbulence encounter. The remaining passengers and crew were not injured. The airplane was traveling in a predominately northern direction at 37,000 feet altitude during the encounter. Weather products obtained showed that extreme intensity thunderstorms existed in the area where the turbulence was encountered. Weather data and aircraft position radar data show that the airplane was 9 miles south-southwest of a cloud buildup that extended to 39,000 feet. Additionally, the airplane was 5 miles west of an extreme intensity radar echo associated with the thunderstorms in the area. The airline's General Operations Manual states that thunderstorms that are identified as severe, or giving a intense radar echo should be avoided by at least 20 miles. No National Weather Service aviation weather advisories were in effect for the location and time of the turbulence encounter. Communications transcripts show that the flight crew requested and were granted a course deviation for weather about 10 minutes prior to the upset. However, the Digital Flight Data Recorder shows that the seat belt sign was illuminated only 10 seconds prior to the encounter.

NTSB Probable Cause Narrative

The flightcrew's failure to follow weather avoidance prcedures and their delay in activating the seat belt sign. Factors were the turbulent thunderstorm weather conditions, and the failure of the National Weather Service to issue an applicable in-flight weather advisory.

Event Information

Type of Event Accident
Event Date 4/18/2002
Event Day of the Week Thursday
Time of Event 1635
Event Time Zone Central Daylight Time
Event City Springfield
Event State MISSOURI
Event Country --
Zipcode of the event site 65721
Event Date Year 2002
Event Date Month 4
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 372911N
Event Location Longitude 0932722W
Event Location Airport --
Event Location Nearest Airport ID --
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 Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1654 Central Daylight Time
Direction of event from weather observation facility (degrees) 180
Weather Observation Facility ID KSGF
Elevation of weather observation facility 1267
Distance of event from weather observation facility (units?) 15
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height 8000
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Unknown
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 8
Air Temperature at event time (in degrees celsius) 23
Dew Point at event time (in degress fahrenheit) 17
Wind Direction (degrees magnetic) 220
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) --
Wind Velocity Indicator Calm
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.94
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report METAR KSGF 182054Z 22005KT 10SM SCT060 25/17 A2993
Event Highest Injury Serious
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor 12
Injury Total None 111
Injury Total Serious 3
Injury Total All 15
Investigating Agency NTSB
NTSB Docket Number (internal use) 14530
NTSB Notification Source FAA
NTSB Notification Date Apr 18 2002 12:00AM
NTSB Notification Time 1700
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Dec 30 2003 8:55AM
User who most recently changed record NTSB\JOHB
Basic weather conditions Visual Meteorological Cond
FAA District Office St. Louis, Missouri

Aircraft Involved

Aircraft #1

Aircraft Registration Number N516AT
NTSB Number CHI02LA111
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 757-200
Aircraft Series Identifier --
Aircraft Serial Number 27972
Certified Max Gross Weight 256000
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 227
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Mar 31 2002 12:00AM
Airframe hours since last inspection 210
Airframe Hours 23720
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name AMERICAN TRANS AIR INC
Aircraft Owner Street Address 7337 West Washington Street
Aircraft Owner City Indianapolis
Aircraft Owner State IN
Aircraft Owner Country USA
Aircraft Owner Zipcode 46231
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 AMTA
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 GDL
Departure City GUADALAJARA
Departure State --
Departure Country MX
Departure Time 1350
Departure Time Zone CDT
Destination Same as Local Flt --
Destination Airport Code MDW
Destination City CHICAGO
Destination State IL
Destination Country USA
Specific Phase of Flight Cruise
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record Oct 20 2003 8:49PM
User who most recently changed record SULP
Since inspection or accident Time of Accident
Event Location Runway Number and Location --
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --