National Transportation Safety Board
Aviation Accident Final Report

 

 

Location:

Buena Vista, CO

Accident Number:

DCA12CA062

Date & Time:

04/15/2012, 0549 UTC

Registration:

N808AW

Aircraft:

AIRBUS INDUSTRIE A319-132

Aircraft Damage:

Minor

Defining Event:

Turbulence encounter

Injuries:

2 Serious, 1 Minor, 95 None

Flight Conducted Under:

Part 121: Air Carrier - Scheduled

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.

 

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
 

an inadvertent encounter with mountain wave turbulence.

 

Findings

Environmental issues

Terrain induced turbulence - Effect on personnel (Cause)

Factual Information

 

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.

 

 

History of Flight

Enroute-descent

Turbulence encounter (Defining event)

 

 

 

 

Aircraft and Owner/Operator Information

Aircraft Make:

AIRBUS INDUSTRIE

Registration:

N808AW

Model/Series:

A319-132

Aircraft Category:

Airplane

Year of Manufacture:

 

Amateur Built:

No

Airworthiness Certificate:

Transport

Serial Number:

1088

Landing Gear Type:

Tricycle

Seats:

179

Date/Type of Last Inspection:

 

Certified Max Gross Wt.:

 

Time Since Last Inspection:

 

Engines:

2 Turbo Jet

Airframe Total Time:

 

Engine Manufacturer:

IAE

ELT:

 

Engine Model/Series:

V2500SERIES

Registered Owner:

U S BANK NA TRUSTEE

Rated Power:

25000 lbs

Operator:

US AIRWAYS INC

Operating Certificate(s) Held:

Flag carrier (121)

Operator Does Business As:

 

Operator Designator Code:

USAA

 

Meteorological Information and Flight Plan

Conditions at Accident Site:

Visual Conditions

Condition of Light:

Night/Dark

Observation Facility, Elevation:

 

Distance from Accident Site:

 

Observation Time:

 

Direction from Accident Site:

 

Lowest Cloud Condition:

 

Visibility

 

Lowest Ceiling:

 

Visibility (RVR):

 

Wind Speed/Gusts:

/

Turbulence Type Forecast/Actual:

/

Wind Direction:

 

Turbulence Severity Forecast/Actual:

/

Altimeter Setting:

 

Temperature/Dew Point:

 

Precipitation and Obscuration:

 

Departure Point:

Phoenix, AZ (KPHX)

Type of Flight Plan Filed:

IFR

Destination:

Denver, CO

Type of Clearance:

IFR

Departure Time:

0450 UTC

Type of Airspace:

 

 

 

Wreckage and Impact Information

Crew Injuries:

2 Serious, 3 None

Aircraft Damage:

Minor

Passenger Injuries:

1 Minor, 92 None

Aircraft Fire:

None

Ground Injuries:

N/A

Aircraft Explosion:

None

Total Injuries:

2 Serious, 1 Minor, 95 None

Latitude, Longitude:

38.835000, -106.278889 (est)

 


 


Administrative Information

Investigator In Charge (IIC):

Daniel R Bower

Report Date:

03/09/2018

Additional Participating Persons:

 

Publish Date:

03/09/2018

Note:

This accident report documents the factual circumstances of this accident as described to the NTSB.

Investigation Docket:

http://dms.ntsb.gov/pubdms/search/dockList.cfm?mKey=83410