FTW03LA121

NTSB accident investigation · Boeing 737-924 · Palestine, TX · April 6, 2003

Accident · Serious injuriesLimited investigationFinal report
Date
April 6, 2003, 10:55 local (15:55 UTC)
Place
Palestine, TX
Injuries
1 serious, 89 uninjured
Damage
No damage
Phase of flight
Enroute
Aircraft
N71411Boeing 737-924
Weather
Visual (VMC) · Day
Status
Completed · report October 28, 2004
Report
Approved by Office Director
Parties
Federal Aviation Administration
FAA report
20030406005019A
Case key
56758

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 airplane's encounter with unforecasted clear air turbulence during cruise flight.

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.

In flight encounter with weatherCruise
Weather condition - turbulence,clear airCause

Analysis

The transport category airplane encountered severe turbulence while deviating around weather at flight level 280 (FL280). The captain had informed the flight attendants to leave the carts stowed and sit down because they might get "a few bumps" for the next minutes or so. The "Fasten Seat Belt" sign was illuminated, and had not been turned off since takeoff. A few minutes later the airplane encountered "moderate turbulence" with no preceding chop. One flight attendant, who was in the aft galley was trying to stow away the beverage cart after receiving a call reporting turbulence the airplane may encounter. While trying to stow the cart away, the cart rolled into her right side, resulting in a fractured femur. Following the turbulence encounter, the airplane diverted to another airport and landed without further incident.

Factual narrative

On April 6, 2003, at 1055 central daylight time, a Boeing 737-924 transport category airplane, N71411, operating as Continental Airlines Flight 111, was undamaged after an encounter with severe turbulence during cruise flight near Palestine, Texas. The airplane was registered to, and operated by Continental Airlines, Inc., of Houston, Texas. The captain, first officer, 4 flight attendants and 83 passengers were not injured; however, one flight attendant sustained serious injuries. Visual meteorological conditions prevailed, and an instrument flight rules (IFR) flight plan was filed for the 14 Code of Federal Regulations Part 121 scheduled passenger flight. The domestic cross-country flight originated from the George Bush Intercontinental Airport, near Houston, Texas, at 1032, and was destined for the Salt Lake City International Airport (SLC), near Salt Lake City, Utah.

According to the captain, during cruise flight at flight level (FL) 280 and deviating around weather, the airplane encountered severe turbulence near the RIKKS intersection. RIKKS is located at the intersection of the 083 degree radial from the Leona Vortac and the 339 degree radial from the Waco Vortac.

Prior to the encounter with turbulence, the captain had instructed the flight attendants to leave the carts stowed and sit down due to the possibility of encountering "a few bumps" for the next few minutes. The "Fasten Seat Belt" sign was illuminated, and had not been turned off since takeoff. A few minutes after the captain issued the instructions, the airplane encountered "moderate turbulence" with no preceding chop.

One flight attendant, who was in the aft galley trying to stow away the beverage cart when the turbulence was encountered was injured by the cart. She reported that the cart rolled into her right side, resulting in a fractured femur.

Flight 111 diverted to the Dallas Fort Worth International Airport (DFW), near Dallas-Fort Worth, Texas, and landed without further incident.

According to the Flight Data Recorder (FDR) factual report indicated that turbulence was encountered at an altitude of approximately 28,000 feet mean sea level and a magnetic heading of approximately 332 degrees. According to the data, the autopilot went from the engaged mode to the off-mode approximately 8 seconds after the turbulence upset and was turned back on about 40 seconds later. The severe turbulence encounter lasted for 14 seconds. During the turbulence, the vertical acceleration parameter recorded a maximum of +2.16 g's and a minimum of 0.00 g's. The lateral acceleration parameter recorded a maximum of +0.18 g's and a minimum of -0.18 g's. The longitudinal acceleration parameter recorded a maximum of +0.08 g's and a minimum of -0.03 g's. The aircraft entered the turbulence in a right roll of approximately +14 degrees. During the turbulence the roll changes to -7.7 degrees and then goes back to +4.4 degrees. At the moment the autopilot parameter reengages, the aircraft has a roll attitude of 0 degrees. The aircraft's pitch at the beginning of the turbulence is 2.1 degrees.

Aircraft

Registration
N71411
Reported as
Boeing 737-924
Category
Airplane
Serial number
30128
Airframe hours
3,769
Engines
CFM International CFM56-7B26, 26,300 horsepower, turbo fanCFM International CFM56-7B26, 26,300 horsepower, turbo fan
Damage
No damage
Flight
Part 121
Registered owner
Continental Airlines
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · April 5, 2003 · 4 hours before
Departed
IAH · Houston, TX
Destination
SLC · Salt Lake City, UT
Flight plan
IFR

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
46
Injuries
None
Certificates
Commercial, Flight instructor, Airline transport, Flight engineer
Airplane ratings
Multi-engine sea, Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Last flight review
April 1, 2002
Seat
Left
Flight hours
12,830 total · 4,050 in this make and model · 8,560 as pilot in command · 232 in the last 90 days · 74 in the last 30 days · 7 in the last 24 hours
Role
Co-pilot
Age
41
Injuries
None
Certificates
Flight engineer, Commercial, Airline transport, Flight instructor
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Last flight review
January 8, 2003
Seat
Right
Flight hours
13,000 total · 3,800 in this make and model · 3,700 as pilot in command · 250 in the last 90 days · 90 in the last 30 days · 7 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
200° at 13 knots
Visibility
8 statute miles
Lowest ceiling
None
Temperature
75 °F, dew point 70 °F
Altimeter
29.72 inHg

FAA reports on this event · 1

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