DCA13CA128

NTSB accident investigation · Boeing 777-232 · Atlanta, GA · July 12, 2013

Accident · Serious injuriesData collectionFinal report
Date
July 12, 2013, 05:38 local (09:38 UTC)
Place
Atlanta, GA
Injuries
1 serious, 278 uninjured
Damage
No damage
Phase of flight
Enroute
Aircraft
N863DABoeing 777-232
Defining event
Enroute-descent: Turbulence encounter
Weather
Visual (VMC) · Night/dark
Status
Completed · report September 1, 2015
Report
Approved by Office Director
NTSB office
Major Investigations Division
Case key
87472

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

Unexpected encounter with convective turbulence while the flight attendants were preparing the cabin for arrival.

Findings · 1

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.

Turbulence: convective turbulenceEnvironmental issues › Conditions/weather/phenomena · Effect on personnelBoeing 777-232: 1 caseAll aircraft: 145 casesProbable cause

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

According to the flight and cabin crew statements, Atlanta Approach Control advised the crew that radar was showing an area of rain on the arrival route although the flight crew did not see any areas of precipitation on the airborne weather radar. During the descent to 11,000 feet the seatbelt sign was illuminated and the captain, who was the pilot monitoring, cycled the seatbelt sign and called the flight attendant (FA) at the 1L door via the interphone to notify the cabin crew to be seated. Before the 1L flight attendant was able to relay the message to all of the FAs to be seated, as they were all preparing the cabin for arrival, the airplane encountered several distinct jolts of turbulence. According to the flight data recorder data, as the airplane was descending through about 13,200 feet, the vertical acceleration fluctuated between +1.56 g's and +0.024 g's over a period of about 10 seconds. During the turbulence the 4Rc FA who was in the aisle near the 3R door was lifted into the air and fell back down to the floor on her feet and knees. The FA was assisted to the 3R jumpseat, the flight crew was notified of the injury, and they requested paramedics meet the airplane upon arrival The 4Rc FA was transported to the hospital where she was diagnosed with two broken ankles.

Factual narrative

According to the flight and cabin crew statements, Atlanta Approach Control advised the crew that radar was showing an area of rain on the arrival route although the flight crew did not see any areas of precipitation on the airborne weather radar. During the descent to 11,000 feet the seatbelt sign was illuminated and the captain, who was the pilot monitoring, cycled the seatbelt sign and called the flight attendant (FA) at the 1L door via the interphone to notify the cabin crew to be seated. Before the 1L flight attendant was able to relay the message to all of the FAs to be seated, as they were all preparing the cabin for arrival, the airplane encountered several distinct jolts of turbulence. According to the flight data recorder data, as the airplane was descending through about 13,200 feet, the vertical acceleration fluctuated between +1.56 g's and +0.024 g's over a period of about 10 seconds. During the turbulence the 4Rc FA who was in the aisle near the 3R door was lifted into the air and fell back down to the floor on her feet and knees. The FA was assisted to the 3R jumpseat, the flight crew was notified of the injury, and they requested paramedics meet the airplane upon arrival The 4Rc FA was transported to the hospital where she was diagnosed with two broken ankles.

Aircraft

Registration
N863DA
Reported as
Boeing 777-232
Category
Airplane
Serial number
29735
Engines
Rolls-Royc RB.211 SERIES, 22,000 lbs thrust, turbo jetRolls-Royc RB.211 SERIES, 22,000 lbs thrust, turbo jet
Damage
No damage
Flight
Part 121
Operator
Delta Air Lines Inc
Registered owner
Delta Air Lines Inc
Airworthiness certificate
Standard, Transport
Departed
OMDB · Dubai
Destination
KATL · Atlanta, GA
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
56
Injuries
None
Certificate
Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Unknown
Last flight review
May 5, 2013
Seat
Left
Flight hours
13,394 total · 1,136 in this make and model · 5,757 as pilot in command · 87 in the last 90 days · 1 in the last 24 hours
Role
Co-pilot
Age
52
Injuries
None
Certificate
Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Unknown
Last flight review
January 15, 2013
Seat
Right
Flight hours
9,499 total · 616 in this make and model · 517 as pilot in command · 94 in the last 90 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Night/dark
Wind
Calm
Visibility
7 statute miles
Lowest ceiling
4,800 ft broken
Temperature
73 °F, dew point 72 °F
Altimeter
29.90 inHg
Observed at
KATL, 29 nm away

Docket · 5

The files NTSB released with the investigation on September 1, 2015, on NTSB’s docket system: statements, records, photos and specialists’ reports. 4.3 MB in all.

Other investigations on N863DA · 1

Matched to the same aircraft by N-number and date.