CHI93LA224

NTSB accident investigation · Boeing 757-222 · Baraboo, WI · June 24, 1993

Accident · Serious injuriesLimited investigationFinal report
Date
June 24, 1993, 12:29 local (17:29 UTC)
Place
Baraboo, WI
Injuries
1 serious, 147 uninjured
Damage
No damage
Phase of flight
Enroute
Aircraft
N579UABoeing 757-222
Weather
Instrument (IMC) · Day
Status
Completed · report August 17, 1994
Report
Approved by Office Director
FAA report
19930624036859A
Case key
9226

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

an encounter with moderate turbulence in the clouds.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Altitude deviation,uncontrolledDescent - normal
Weather condition - turbulence in cloudsCause

Analysis

The airplane was descending on a vector for landing on runway 14R at chicago o'hare international airport. Passing through flight level 290 there was a short encounter with moderate turbulence while still in the clouds. One flight attendant fell and injured her ankle during the encounter. When she was treated for the injury, it was discovered that she had sustained a fractured ankle.

Factual narrative

On June 24, 1993 at 1229 central daylight time, a Boeing 757-222, N579UA, operated by United Airlines, Inc., as flight number 1218, encountered moderate turbulence in the clouds at flight level 290, over Baraboo, Wisconsin, while descending on a vector for an approach runway 14R at Chicago O'Hare International Airport. The operator reported the seat belt sign was on, the weather radar was on, and the airplane was clear of any green returns on the radar. One flight attendant sustained serious injuries. There were no injuries to the two cockpit crewmembers, five other flight attendants, or 140 passengers aboard the airplane. The flight was operating under 14 CFR Part 121, and originated at Vancouver, British Columbia, Canada, at 0920. The destination was O'Hare Airport. An IFR flight plan was filed, and instrument meteorological conditions prevailed at the time.

During the turbulence encounter, the flight attendant fell and injured her left ankle. She was treated for the injury on completion of the flight. The injury was diagnosed as a fractured ankle.

Aircraft

Registration
N579UA
Reported as
Boeing 757-222
Category
Airplane
Serial number
26697
Engine
turbo fan
Damage
No damage
Flight
Part 121
Registered owner
United Airlines
Airworthiness certificate
Standard, Transport
Departed
YVR · Vancouver
Destination
ORD · Chicago, IL
Flight plan
IFR

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Certificate
Airline transport
Airplane ratings
Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Left

Weather

Conditions
Instrument (IMC) · Day
Wind
160° at 16 knots
Visibility
8 statute miles
Lowest ceiling
8,500 ft overcast
Temperature
84 °F, dew point 72 °F
Altimeter
29.00 inHg
Observed at
MSN, 30 nm away

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.