CEN09LA256

NTSB accident investigation · Boeing 737-724 · McAllen, TX · April 18, 2009

Accident · Serious injuriesLimited investigationFinal report
Date
April 18, 2009, 01:52 local (06:52 UTC)
Place
McAllen, TX
Injuries
1 serious, 3 minor, 105 uninjured
Damage
No damage
Phase of flight
Enroute
Aircraft
N27722Boeing 737-724
Defining event
Enroute-descent: Turbulence encounter
Weather
Visual (VMC) · Night
Status
Completed · report May 28, 2010
Report
Approved by Office Director
NTSB office
Central Region
Parties
Continental Airlines
FAA report
20090418008699A
Case key
73693

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

The injured passenger's failure to comply with the requirement to remain seated with a fastened seatbelt.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

TurbulenceEnvironmental issues › Conditions/weather/phenomena · Compliance w/ procedureBoeing 737-724: 2 casesAll aircraft: 92 cases
Communication (personnel): following instructionsPersonnel issues › Task performance · PassengerBoeing 737-724: 1 caseAll aircraft: 31 casesProbable cause
TurbulenceEnvironmental issues › Conditions/weather/phenomena · Effect on personnelBoeing 737-724: 2 casesAll aircraft: 92 cases

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

Before departure the captain briefed all crew members not to perform any services and remain in their jump seats for the duration of the flight due to the possibility of severe weather. The lead flight attendant then made a public address announcement to the passengers that due to possible bad weather there would be no service and the seat belt sign would remain on during the entire flight, stressing the need for the passengers to remain in their seats. In addition, the first officer made a similar announcement to the crew and passengers stressing the need to remain seated for their safety. While descending to the destination airport, a passenger who had gotten up and went into the lavatory sustained serious injuries when the airplane encountered an area of severe turbulence. In addition, two passengers and a flight attendant not wearing their seatbelts sustained minor injuries.

Factual narrative

On April 18, 2009 at 0152 (Unless otherwise noted, all times in this report are central daylight time based on a 24-hour clock) a Boeing 737-724, N27722 encountered severe turbulence while descending for approach to McAllen Miller International Airport (KMFE). The flight was being operated by Continental Airlines as Flight 511, a Title 14 Code of Federal Regulations (CFR) Part 121 scheduled domestic passenger flight from George Bush Intercontinental/Houston Airport (KIAH), Houston, Texas, to McAllen Miller International Airport (KMFE), McAllen, Texas. The flight was being conducted during night instrument conditions with an active instrument flight rules (IFR) flight plan. A total of 109 people were on board consisting of 2 flight crew, 3 flight attendants, and 104 passengers. One flight attendant sustained minor injuries, 2 passengers sustained minor injuries, and 1 passenger was critically injured. The airplane landed at KMFE at 0216, and arrived at the gate at 0220. In a written report the captain stated that he had briefed all crew members not to perform any services and remain in their jump seats for the duration of the flight due to the possibility of severe weather. The lead flight attendant made a public address announcement to the passengers that due to possible bad weather there would be no service and the seat belt sign would remain on during the entire flight and stressed the need for the passengers to remain in their seats. The flight took off from Houston approximately 3 hours later than scheduled and climbed to 38,000 feet. While en route to KMFE, the pilot had to circumnavigate to avoid thunderstorm cells. The first officer made a similar announcement to the crew and passengers stressing the need to remain seated for their safety. A total of 4 or 5 announcements were made to passengers during the flight to please remain in their seats as several passengers attempted to get up to use the lavatories. The seat belt sign was illuminated for the entire flight. The descent to KMFE began, with the airplane at an airspeed of 280 knots and a descent rate of approximately 1,000 feet per minute. A line of precipitation about 5 to 10 nautical miles wide was indicated on the airplane's weather radar. The depiction was green in color from -2 to +2 degrees. The airplane entered a cloud formation about 20,000 feet mean seal level (MSL) and encountered severe turbulence for about 15 seconds. This included up and down drafts and a roll of about 30 degrees. During the turbulence encounter a passenger, who had gotten up and went into the lavatory, sustained serious injuries. In addition, two passengers and a flight attendant not wearing their seatbelts sustained minor injuries. The descent continued to 10,000 feet MSL as cleared. At that time the lead flight attendant called the captain and notified him of injuries in the aft cabin. The captain continued to the approach and communicating with Air Traffic Control (ATC) the need to land as quickly aspossible for a medical emergency. The flight data recorder was removed and secured for further analysis and the airplane was inspected for damage in accordance with Continental and Boeing maintenance manuals. There was no damage noted and the airplane was released for further flight.

Aircraft

Registration
N27722
Reported as
Boeing 737-724
Category
Airplane
Serial number
28789
Engines
CFM Intl. CFM56 SERIES, 2,200 horsepower, turbo jetCFM Intl. CFM56 SERIES, 2,200 horsepower, turbo jet
Damage
No damage
Flight
Part 121
Operator
Continental Airlines Inc, doing business as Continental Airlines
Registered owner
Continental Airlines Inc
Airworthiness certificate
Standard, Normal
Departed
KIAH · Houston, TX
Destination
KMFE · McAllen, TX
Flight plan
IFR
Airport
KMFE · McAllen Miller 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
49
Injuries
None
Certificates
Military, Flight engineer, Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
November 9, 2008
Seat
Left
Flight hours
12,000 total · 6,500 in this make and model · 125 in the last 90 days · 50 in the last 30 days · 8 in the last 24 hours
Role
Co-pilot
Age
36
Injuries
None
Certificates
Flight instructor, Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
July 1, 2008
Seat
Right
Flight hours
6,707 total · 2,417 in this make and model · 2,450 as pilot in command · 217 in the last 90 days · 82 in the last 30 days · 10 in the last 24 hours

Weather

Conditions
Visual (VMC) · Night
Wind
120° at 14 knots
Visibility
7 statute miles
Temperature
77 °F, dew point 72 °F
Altimeter
29.81 inHg
Observed at
KFME

Docket · 6

The files NTSB released with the investigation on March 2, 2010, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.0 MB in all.

FAA reports on this event · 1

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