Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Dickinson, North Dakota 58601
Thursday, July 10, 1997 15:41 MDT
NTSB Narrative Summary Released at Completion of Accident
The airplane was in level cruise flight at FL370, flying in an area of widely scattered thunderstorm cells. The airborne weather radar was set to the 160 nm scale, and the tilt was approximately 1 to 2 degrees down. One cell was observed 20 nm to the left of the airplane towering above its altitude, a second cell was 40 nm to the right, and a third cell 'came up independently underneath' and in front of the airplane. The FASTEN SEATBELT sign was not illuminated, but earlier, the captain had delivered an address to the passengers advising them of the possibility of a bumpy ride ahead and to '...keep your seatbelts on while in your seats.' The flight encountered convection induced turbulence (CIT), which resulted in minor injuries to 20 passengers and 2 flight attendants. There were no injuries to the other 120 passengers and 5 crew members. Vertical acceleration was between +2.01 and -0.75 g's. American Airlines meteorologists prepared the flight plan and entered a turbulence index of '0' for that segment of flight (from Billings, Mt, to Dupree, SD), indicating smooth air on average for the segment. Convective activity had been forecast for the area.
NTSB Probable Cause Narrative
an encounter with unforecast convection induced turbulence (CIT). Related factors were: the flight crew's improper evaluation of the weather, and an inaccurate preflight weather briefing by company weather personnel.
Event Information
| Type of Event | Incident |
| Event Date | 7/10/1997 |
| Event Day of the Week | Thursday |
| Time of Event | 1541 |
| Event Time Zone | Mountain Daylight Time |
| Event City | DICKINSON |
| Event State | NORTH DAKOTA |
| Event Country | -- |
| Zipcode of the event site | 58601 |
| Event Date Year | 1997 |
| Event Date Month | 7 |
| 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 | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Not pertinent |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1550 Mountain Daylight Time |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | DIK |
| Elevation of weather observation facility | 2590 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | MDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 25000 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Unknown |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 20 |
| Air Temperature at event time (in degrees celsius) | 32 |
| Dew Point at event time (in degress fahrenheit) | 31 |
| Wind Direction (degrees magnetic) | 150 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 13 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 29 |
| Density Altitude (feet) | 5374 |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | Minor |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | 22 |
| Injury Total None | 133 |
| Injury Total Serious | -- |
| Injury Total All | 22 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1307 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jul 10 1997 12:00AM |
| NTSB Notification Time | 1559 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 8 2000 12:24PM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N660AM |
| NTSB Number | FTW97IA261 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | Minor |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Boeing |
| Aircraft Model | 757-223 |
| Aircraft Series Identifier | 757-223 |
| Aircraft Serial Number | 25294 |
| Certified Max Gross Weight | 251000 |
| 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 | 199 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Continuous Airworthiness |
| Date of Last Inspection | May 21 1997 12:00AM |
| Airframe hours since last inspection | 492 |
| Airframe Hours | 17466 |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | AMERICAN AIRLINES |
| Aircraft Owner Street Address | P.O. BOX 619616 |
| Aircraft Owner City | DFW AIRPORT |
| Aircraft Owner State | TX |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 75261 |
| 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 | AALA |
| Owner has at least one certificate | Yes - certificate holder |
| 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 | Domestic |
| 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 | SEA |
| Departure City | SEATTLE |
| Departure State | WA |
| Departure Country | |
| Departure Time | 1245 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | JFK |
| Destination City | NEW YORK |
| Destination State | NY |
| Destination Country | |
| Specific Phase of Flight | Cruise |
| 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 | -- |