DCA12CA062

NTSB accident investigation · Airbus Industrie A319-132 · Buena Vista, CO · April 15, 2012

Accident · Serious injuriesData collectionFinal report
Date
April 15, 2012, 05:49 UTC
Place
Buena Vista, CO
Injuries
2 serious, 1 minor, 95 uninjured
Damage
Minor damage
Phase of flight
Enroute
Aircraft
N808AWAirbus Industrie A319-132
Defining event
Enroute-descent: Turbulence encounter
Weather
Visual (VMC) · Night/dark
Status
Completed · report March 9, 2018
Report
Approved by Office Director
NTSB office
Major Investigations Division
Case key
83410

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 · 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: terrain induced turbulenceEnvironmental issues › Conditions/weather/phenomena · Effect on personnelAirbus Industrie A319-132: 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 15 April 2012, at approximately 0549 coordinated universal time, US Airways flight 496, an Airbus A319-132, N808AW, encountered severe mountain wave turbulence at flight level 320 in the vicinity of Buena Vista, Colorado. Of the 98 passengers and crew onboard, two flight attendants received serious injuries and one passenger received minor injuries during the encounter. The flight was operating under the provisions of 14 Code of Federal Regulations Part 121 as a regularly scheduled passenger flight between Phoenix Sky Harbor International Airport (KPHX), Phoenix, Arizona, and Denver International Airport (KDEN), Denver, Colorado. According to the operator, the captain was the pilot monitoring, and the first officer (FO) was the pilot flying. The flight was cleared to descend from FL390 to 17,000 feet. The seatbelt sign was on during the descent and there were no pilot reports of turbulence in the area. The captain turned on the weather radar and noted no returns present between the airplane and the airport. As the airplane passed through about FL320, the captain noticed the airspeed rapidly increasing. He disconnected the autopilot while simultaneously notifying the FO of the overspeed and began to apply a nose-up input. The FO also began to command a nose-up input at that time and so the captain released his pitch up input. The crew received an overspeed warning and then encountered severe turbulence. The flight crew stated the encounter lasted about 10 – 15 seconds. After the encounter, both Elevator and Aileron Computers (ELAC) faults were displayed. The FO resumed pilot flying duties while the Captain performed the appropriate actions to reset ELAC 1 and 2, report the encounter to air traffic control and dispatch, and contacted the flight attendants. The A flight attendant (A-FA) was in the forward jumpseat and the B flight attendant (B-FA) and C flight attendant (C-FA) were in the aft galley sitting in their jumpseats without their seatbelts on. During the turbulence encounter, both aft flight attendants struck the overhead ceiling, panels before landing on the floor. Two passengers who were also not wearing their seatbelts were lifted out of their seats and struck the ceiling panels during the encounter. Oxygen masks in several rows of seats were also released as a result of the turbulence. Two onboard medical personnel tended to the B-FA and C-FA with the assistance of the A-FA. The captain declared a medical emergency and arranged for emergency personnel to meet the flight on arrival. At the gate, paramedics transported the two injured flight attendants and one of the injured passengers to the hospital.

Factual narrative

On 15 April 2012, at approximately 0549 coordinated universal time, US Airways flight 496, an Airbus A319-132, N808AW, encountered severe mountain wave turbulence at flight level 320 in the vicinity of Buena Vista, Colorado. Of the 98 passengers and crew onboard, two flight attendants received serious injuries and one passenger received minor injuries during the encounter. The flight was operating under the provisions of 14 Code of Federal Regulations Part 121 as a regularly scheduled passenger flight between Phoenix Sky Harbor International Airport (KPHX), Phoenix, Arizona, and Denver International Airport (KDEN), Denver, Colorado. According to the operator, the captain was the pilot monitoring, and the first officer (FO) was the pilot flying. The flight was cleared to descend from FL390 to 17,000 feet. The seatbelt sign was on during the descent and there were no pilot reports of turbulence in the area. The captain turned on the weather radar and noted no returns present between the airplane and the airport. As the airplane passed through about FL320, the captain noticed the airspeed rapidly increasing. He disconnected the autopilot while simultaneously notifying the FO of the overspeed and began to apply a nose-up input. The FO also began to command a nose-up input at that time and so the captain released his pitch up input. The crew received an overspeed warning and then encountered severe turbulence. The flight crew stated the encounter lasted about 10 – 15 seconds. After the encounter, both Elevator and Aileron Computers (ELAC) faults were displayed. The FO resumed pilot flying duties while the Captain performed the appropriate actions to reset ELAC 1 and 2, report the encounter to air traffic control and dispatch, and contacted the flight attendants. The A flight attendant (A-FA) was in the forward jumpseat and the B flight attendant (B-FA) and C flight attendant (C-FA) were in the aft galley sitting in their jumpseats without their seatbelts on. During the turbulence encounter, both aft flight attendants struck the overhead ceiling, panels before landing on the floor. Two passengers who were also not wearing their seatbelts were lifted out of their seats and struck the ceiling panels during the encounter. Oxygen masks in several rows of seats were also released as a result of the turbulence. Two onboard medical personnel tended to the B-FA and C-FA with the assistance of the A-FA. The captain declared a medical emergency and arranged for emergency personnel to meet the flight on arrival. At the gate, paramedics transported the two injured flight attendants and one of the injured passengers to the hospital.

Aircraft

Registration
N808AW
Reported as
Airbus Industrie A319-132
Category
Airplane
Serial number
1088
Engines
IAE V2500SERIES, 25,000 lbs thrust, turbo jetIAE V2500SERIES, 25,000 lbs thrust, turbo jet
Damage
Minor damage
Flight
Part 121
Operator
US Airways Inc
Registered owner
U S Bank Na Trustee
Airworthiness certificate
Standard, Transport
Departed
KPHX · Phoenix, AZ
Destination
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.

Weather

Conditions
Visual (VMC) · Night/dark

Docket · 8

The files NTSB released with the investigation on March 13, 2018, on NTSB’s docket system: statements, records, photos and specialists’ reports. 5.8 MB in all.