Aircraft Accident/Incident Report

Chicago, Illinois 60666
Sunday, March 2, 1997 5:55 CST

NTSB Narrative Summary Released at Completion of Accident

The flight crew had checked weather for the intended flight from Durango, Mexico, to Chicago, Illinois, including a briefing from an arriving pilot who warned of light to moderate turbulence. The airplane encountered clear air turbulence while descending from 26,000 feet to 20,000 feet which was described as severe. When the turbulence was encountered the flight crew and a flight attendant made an announcement for the passengers to return to their seats and shortly after that, the 'Fasten Seatbelt' sign was turned on. Two of the passengers sustaining serious injuries were occupying the lavatory at the time of the turbulence encounter.

NTSB Probable Cause Narrative

Clear air turbulence.

Event Information

Type of Event Accident
Event Date 3/2/1997
Event Day of the Week Sunday
Time of Event 555
Event Time Zone Central Standard Time
Event City CHICAGO
Event State ILLINOIS
Event Country --
Zipcode of the event site 60666
Event Date Year 1997
Event Date Month 3
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport
Event Location Nearest Airport ID
Indicates whether the acc/inc occurred off or on an airport Unknown
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 556 Central Standard Time
Direction of event from weather observation facility (degrees) 360
Weather Observation Facility ID ORD
Elevation of weather observation facility 666
Distance of event from weather observation facility (units?) 120
Time Zone of the weather observation CST
Lighting Conditions Night/Dark
Lowest Ceiling Height 2500
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Unknown
Sky Condition for Lowest Ceiling Overcast
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) -1
Dew Point at event time (in degress fahrenheit) -4
Wind Direction (degrees magnetic) 300
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 18
Injury Total None 180
Injury Total Serious 4
Injury Total All 22
Investigating Agency NTSB
NTSB Docket Number (internal use) 1863
NTSB Notification Source --
NTSB Notification Date Mar 2 1997 12:00AM
NTSB Notification Time 720
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 8 2000 12:09PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N755AT
NTSB Number CHI97LA078
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 129: Foreign
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage None
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Boeing
Aircraft Model 757-2Q8
Aircraft Series Identifier 757-2Q8
Aircraft Serial Number 24965
Certified Max Gross Weight 256000
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/Foreign Oper.
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 220
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection AAIP
Date of Last Inspection --
Airframe hours since last inspection 806
Airframe Hours --
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name MEXICANA AIRLINES
Aircraft Owner Street Address 9841 AIRPORT BLVD., SUITE 200
Aircraft Owner City LOS ANGELES
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 90045
Operator is an individual? --
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 CMDF
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
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) Unknown
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code DGO
Departure City DURANGO
Departure State MX
Departure Country
Departure Time 335
Departure Time Zone CST
Destination Same as Local Flt crash at destination city
Destination Airport Code ORD
Destination City
Destination State IL
Destination Country
Specific Phase of Flight Descent
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:30AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --