DCA17CA042

NTSB accident investigation · Boeing 737 824 · Denver, CO · December 14, 2016

Accident · Serious injuriesData collectionFinal report
Date
December 13, 2016, 18:47 local (Dec 14, 2016, 01:47 UTC)
Place
Denver, CO
Injuries
1 serious, 173 uninjured
Damage
No damage
Phase of flight
Enroute
Aircraft
N24202Boeing 737 824
Defining event
Enroute-descent: Turbulence encounter
Weather
Instrument (IMC) · Night
Status
Completed · report February 23, 2017
Report
Approved by Office Director
NTSB office
Major Investigations Division
Case key
94507

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 inadvertent encounter with mountain wave turbulence.

Findings · 2

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: terrain induced turbulenceEnvironmental issues › Conditions/weather/phenomena · Effect on personnelBoeing 737-824: 1 caseAll aircraft: 70 casesProbable cause
Turbulence: terrain induced turbulenceEnvironmental issues › Conditions/weather/phenomena · Awareness of conditionBoeing 737-824: 1 caseAll aircraft: 70 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

On December 13, 2016, at 1847 mountain standard time, United Airlines flight 1545, a Boeing 737-800, N24202, experienced turbulence during descent that resulted in one flight attendant sustaining a serious injury. There were no injuries to the other passengers and crew onboard and the airplane was not damaged. The flight was operating under the provisions of 14 Code of Federal Regulations Part 121 as a regularly scheduled passenger flight from San Francisco International Airport (SFO), California to Denver International Airport (DEN), Colorado. The flight landed at DEN with no further incident. According to the operator, weather forecasts indicated that mountain wave turbulence was expected over the Sierra Nevada mountains and moderate turbulence was forecast for the descent in to DEN below 17,000 feet. As the airplane descended through approximately FL270 the captain advised the flight attendants "it's going to get bumpy" and to be seated. The flight crew reported that passing through approximately FL220 the airplane experienced increasing turbulence and then at about FL200 experienced a "big jolt." The flight attendant in position 2L was securing the galley at the time of the turbulence and was thrown to the ceiling and then struck her face on the galley counter while falling to the floor. She suffered multiple injuries including a large gash to her cheek and a fractured facial bone.

Factual narrative

On December 13, 2016, at 1847 mountain standard time, United Airlines flight 1545, a Boeing 737-800, N24202, experienced turbulence during descent that resulted in one flight attendant sustaining a serious injury. There were no injuries to the other passengers and crew onboard and the airplane was not damaged. The flight was operating under the provisions of 14 Code of Federal Regulations Part 121 as a regularly scheduled passenger flight from San Francisco International Airport (SFO), California to Denver International Airport (DEN), Colorado. The flight landed at DEN with no further incident. According to the operator, weather forecasts indicated that mountain wave turbulence was expected over the Sierra Nevada mountains and moderate turbulence was forecast for the descent in to DEN below 17,000 feet. As the airplane descended through approximately FL270 the captain advised the flight attendants "it's going to get bumpy" and to be seated. The flight crew reported that passing through approximately FL220 the airplane experienced increasing turbulence and then at about FL200 experienced a "big jolt." The flight attendant in position 2L was securing the galley at the time of the turbulence and was thrown to the ceiling and then struck her face on the galley counter while falling to the floor. She suffered multiple injuries including a large gash to her cheek and a fractured facial bone.

Aircraft

Registration
N24202
Reported as
Boeing 737 824 (824)
Category
Airplane
Serial number
30429
Built
2000
Engines
CFM Intl. CFM56 SERIES, turbo fanCFM Intl. CFM56 SERIES, turbo fan
Damage
No damage
Flight
Part 121
Operator
United Airlines
Registered owner
Wells Fargo Bank Northwest NA Trustee
Airworthiness certificate
Standard, Transport
Departed
SFO · San Francisco, CA
Destination
DEN · Denver, CO
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
47
Injuries
None
Certificates
Commercial, Private, Airline transport
Airplane ratings
Single-engine land, Multi-engine land, Single-engine sea
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
November 24, 2015
Seat
Left
Restraint
5-point
Flight hours
16,730 total · 4,698 in this make and model · 9,430 as pilot in command · 184 in the last 90 days · 64 in the last 30 days · 5 in the last 24 hours
Role
Co-pilot
Age
53
Injuries
None
Certificates
Military, Commercial, Airline transport, Private, Flight engineer
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Waiver time limited special
Last flight review
October 25, 2016
Seat
Right
Restraint
Lap only
Flight hours
5,960 total · 3,150 in this make and model · 0 as pilot in command · 241 in the last 90 days · 80 in the last 30 days · 7 in the last 24 hours

Weather

Conditions
Instrument (IMC) · Night
Turbulence
Moderate

Docket · 8

The files NTSB released with the investigation on February 23, 2017, on NTSB’s docket system: statements, records, photos and specialists’ reports. 4.4 MB in all.

Other investigations on N24202 · 1

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