Individually Owned: 150,657
Corporate Owned: 137,281
O'hare Int'l Airport
Aircraft Accident/Incident Report
Chicago, Illinois 60666
Thursday, September 17, 1998 19:33 CDT
NTSB Narrative Summary Released at Completion of Accident
Flight 146, an ATR-42 was approximately 18 miles from the airport on the ILS 09R approach when it encountered wake turbulence from a Flight 554, a Boeing 737-300, which was vectored onto the approach from the north in front of Flight 146. Radar data showed Flight 554 intercepted the localizer approximately 17.5 miles from the airport while descending from 5,200 feet to 4,800 feet. Flight 146 was at an altitude of about 4,900 feet when the wake turbulence encounter occurred. Separation of the two airplanes when the encounter occurred was approximately 4.8 miles. Vertical acceleration of Flight 146 varied from 2.3679 g's to .5542 g's during the encounter.
NTSB Probable Cause Narrative
the wake turbulence encountered by Flight 146.
Event Information
| Type of Event | Accident |
| Event Date | 9/17/1998 |
| Event Day of the Week | Thursday |
| Time of Event | 1933 |
| Event Time Zone | Central Daylight Time |
| Event City | CHICAGO |
| Event State | ILLINOIS |
| Event Country | -- |
| Zipcode of the event site | 60666 |
| Event Date Year | 1998 |
| Event Date Month | 9 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | O'HARE INT'L |
| 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 | 18 |
| Degrees magnetic from airport | 270 |
| Airport Elevation | -- |
| Weather Briefing Completeness | Full |
| Investigator's weather source | Unknown |
| Time of the weather observation | 0 |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 8000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| 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) | 22 |
| Dew Point at event time (in degress fahrenheit) | -12 |
| Wind Direction (degrees magnetic) | 40 |
| 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) | 30 |
| 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 | -- |
| Injury Total None | 15 |
| Injury Total Serious | 1 |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1067 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Sep 18 1998 12:00AM |
| NTSB Notification Time | 817 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 11 2000 11:45AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N233RM |
| NTSB Number | CHI98LA351 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 121: Air Carrier |
| Type of Flight Plan filed | IFR |
| Flight plan Was Activated? | -- |
| Damage | None |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Aerospatiale |
| Aircraft Model | ATR-42-300 |
| Aircraft Series Identifier | ATR-42-300 |
| Aircraft Serial Number | 235 |
| Certified Max Gross Weight | 37258 |
| 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 | 49 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | AAIP |
| Date of Last Inspection | Jun 6 1997 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | IDEFIX LEASING CORP |
| Aircraft Owner Street Address | 1209 ORANGE ST. |
| Aircraft Owner City | WILMINGTON |
| Aircraft Owner State | DE |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 19801 |
| Operator is an individual? | -- |
| Operator Name | AMERICAN EAGLE, INC. |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 43333 AMON CARTER BLVD |
| Operator City | FT. WORTH |
| Operator State | TX |
| Operator Country | |
| Operator Zip code | 76155 |
| Operator Code | SIMA |
| 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 | CWA |
| Departure City | MOSINEE |
| Departure State | WI |
| Departure Country | |
| Departure Time | 1836 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | ORD |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Approach |
| 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 | -- |