CHI04LA127

NTSB accident investigation · McDonnell Douglas DC-9-82 (MD-82) · Near St. Louis, MO · May 26, 2004

Accident · Serious injuriesLimited investigationFinal report
Date
May 26, 2004, 17:20 local (22:20 UTC)
Place
Near St. Louis, MO
Injuries
1 serious, 1 minor, 86 uninjured
Damage
No damage
Phase of flight
Enroute
Aircraft
N573AAMcDonnell Douglas DC-9-82 (MD-82)
Weather
Visual (VMC) · Day
Status
Completed · report February 24, 2005
Report
Approved by Office Director
Parties
FAA
FAA report
20040526014349A
Case key
59337

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

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Probable cause

The unexpected encounter with convective turbulence which resulted in a flight attendant being injured.

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
Weather condition - turbulence,convection inducedCause

Analysis

A flight attendant was seriously injured and a passenger received a minor injury when the airplane encountered turbulence during an arrival descent. The airplane was descending through 12,000 feet at 280 to 290 knots when it encountered an updraft. The captain reported they had just entered the cloud tops when they encountered an updraft that lasted about 2 seconds. The cockpit crew was then informed that a flight attendant in the rear of the airplane was thrown off her feet and injured. A passenger who was in the lavatory when the turbulence was encountered, reported that he hit his head. The flight crew declared an emergency. The flight was immediately cleared for an approach, and they were met by medical personnel after an uneventful landing. The passenger refused treatment. The flight attendant was transported to a hospital where it was determined that she suffered broken ribs, a fractured wrist, and pelvic fractures. According to crewmembers, the seatbelt sign was on when the turbulence was encountered. Although storms were not present along the flight path, SIGMETS had been issued for severe storms in the surrounding area. Approximately 15 minutes after this accident, another MD-80 reported severe turbulence along the same route.

Factual narrative

On May 26, 2004, at 1720 central daylight time, a McDonnell Douglas DC-9-82 (MD-82), N573AA, operated by American Airlines as flight 1396, encountered turbulence during descent into the Lambert International Airport (STL), St. Louis, Missouri. One flight attendant received serious injuries and one passenger received a minor injury. The captain, first officer, 2 remaining flight attendants, and 82 passengers were not injured. The 14 CFR Part 121 scheduled domestic passenger flight was operating in instrument meteorological conditions on an instrument flight rules flight plan at the time of the encounter. The flight originated from Orange County, California, at 1228 pacific daylight time. The flight continued to its original destination of STL where it landed uneventfully.

The captain's report stated they were on the TRAKE arrival into STL and they were deviating to the south due to weather. As they were descending at 280 to 290 knots through 12,000 feet they encountered an updraft which lasted about 2 seconds. They had just entered the cloud tops when this occurred. The cockpit crew was then informed that a flight attendant in the rear of the airplane was thrown off her feet and injured when they encountered the turbulence. Another passenger who was in the lavatory when the turbulence was encountered, reported that he hit his head. The flight crew declared an emergency. The captain reported they were immediately cleared for the approach and they landed on runway 12R at STL without incident. Emergency personnel met the airplane. The flight attendant was removed from the airplane and transported to the hospital where it was determined that she suffered broken ribs, a fractured wrist, and pelvic fractures. The passenger refused medical treatment.

According to crewmembers, the seatbelt sign was on when the turbulence was encountered.

Another flight attendant who was in the aisle reported, "The plane dipped severely and I nearly hit the ceiling. I came down hard on my knees. I immediately took the nearest pax [passenger] seat and strapped in." This flight attendant reported that a few minutes later a passenger came up the aisle to inform the number 1 flight attendant that the flight attendant in the rear of the airplane had been injured.

The flight was deviating 15 nautical miles (nm) south of a thunderstorm when the turbulence was encountered. The airplane was 30 distance measuring equipment (DME) on the 247 Radial from the Forristell very high frequency omnidirectional range (FTZ VOR) or approximately 55 nm west-southwest of STL when it encountered the turbulence. Scattered thunderstorms were forecast for the area. Convective Sigmet 25C was issued at 1555 valid until 1755 for an area 50 miles south-southwest of Decatur, Illinois, to 20 miles east of Columbia, Missouri. This Sigmet reported a line of thunderstorms 35 nm wide moving from 260 degrees at 50 knots with tops to 35,000 feet. Tornadoes, 2-inch hail, and wind gusts to 60 knots were possible. This line of storms continued to move to the east-southeast. Convective Sigmet 33C was issued at 1755 valid until 1955 for an area 30 miles north-northeast of Quincy, Illinois, to 50 miles south of Terre Haute, Indiana, to 20 miles east-northeast of Springfield, Missouri, to 30 miles north-northeast of Quincy, Illinois. This Sigmet reported an area of severe thunderstorms moving form 250 degrees at 55 knots with tops to 41,000 feet.

At 1735, another MD-80 pilot reported an encounter with severe turbulence at 11,000 feet, about 40 miles west-southwest of STL.

Aircraft

Registration
N573AA
Reported as
McDonnell Douglas DC-9-82 (MD-82)
Category
Airplane
Serial number
53092
Airframe hours
38,987
Engine
Pratt & Whitney JT8D-200-7C, 21,000 lbs thrust, turbo jet
Damage
No damage
Flight
Part 121
Registered owner
American Airlines, Inc.
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · May 23, 2004
Departed
SNA · Orange County, CA
Destination
STL · St. Louis, MO
Flight plan
IFR
Airport
STL · St. Louis International

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
58
Injuries
None
Certificates
Flight engineer, Airline transport, Flight instructor, Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
17,531 total · 4,329 in this make and model · 6,790 as pilot in command
Role
Co-pilot
Age
52
Injuries
None
Certificates
Flight engineer, Commercial, Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Last flight review
October 24, 2003
Seat
Right
Flight hours
9,846 total · 5,819 in this make and model · 1,839 as pilot in command

Weather

Conditions
Visual (VMC) · Day
Wind
80° at 8 knots
Visibility
4 statute miles
Lowest ceiling
10,000 ft overcast
Temperature
63 °F, dew point 63 °F
Altimeter
29.75 inHg
Observed at
STL, 62 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.