DCA15CA131

NTSB accident investigation · Bombardier CL600 2D24 · McCook, NE · June 10, 2015

Accident · Serious injuriesData collectionFinal report
Date
June 10, 2015, 16:14 local (21:14 UTC)
Place
McCook, NE
Injuries
1 serious, 4 minor, 75 uninjured
Damage
No damage
Phase of flight
Enroute
Aircraft
N246LRBombardier CL600 2D24
Defining event
Enroute-cruise: Turbulence encounter
Weather
Day
Status
Completed · report April 8, 2016
Report
Approved by Office Director
NTSB office
Major Investigations Division
FAA report
20150610011239A
Case key
91347

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

inadvertent encounter with turbulence while deviating around an area of known convective activity.

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.

Convective weather: thunderstormEnvironmental issues › Conditions/weather/phenomena · Contributed to outcomeBombardier CL-600-2D24: 1 caseAll aircraft: 100 casesProbable cause
Turbulence: convective turbulenceEnvironmental issues › Conditions/weather/phenomena · Effect on operationBombardier CL-600-2D24: 4 casesAll 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 crew, they were deviating around known convective activity and anticipated some turbulence. The flight crew stated they selected the fasten seatbelt sign on approximately two minutes prior to the turbulence encounter. The flight was level at FL370 about 80 miles southwest of McCook, Nebraska when they encountered turbulence characterized by the flight crew as severe. FDR data indicated the airplane was level with airspeed of 258 knots, when the airspeed momentarily increased to 268 knots and varied between 268 and 244 knots over the next 10 seconds. There was an approximately 10 second period of fluctuations in both vertical and lateral acceleration. The vertical acceleration fluctuated between -.55 g's to a peak of +1.64 g's while lateral acceleration changed from -.13 g's to +.23 g within three seconds. The flight attendant in the forward jumpseat was making an announcement regarding the seatbelt sign and hit her head on the back of the jumpseat when the flight encountered turbulence. She reported that she saw a passenger in the rear of the cabin thrown against the ceiling and then back down to the floor and another passenger displaced from her seat hit her head on the overhead storage compartments. A passenger in the aft lavatory was thrown against the ceiling and wall and two additional passengers were displaced from their seats. The cabin crew contacted the flight crew to notify them of the injuries, and the flight crew arranged for paramedics to meet the airplane at the destination airport. Three passengers were transported to a local hospital. All were treated and released; one was diagnosed with a dislocated shoulder and a chipped bone.

Factual narrative

According to the flight crew, they were deviating around known convective activity and anticipated some turbulence. The flight crew stated they selected the fasten seatbelt sign on approximately two minutes prior to the turbulence encounter. The flight was level at FL370 about 80 miles southwest of McCook, Nebraska when they encountered turbulence characterized by the flight crew as severe. FDR data indicated the airplane was level with airspeed of 258 knots, when the airspeed momentarily increased to 268 knots and varied between 268 and 244 knots over the next 10 seconds. There was an approximately 10 second period of fluctuations in both vertical and lateral acceleration. The vertical acceleration fluctuated between -.55 g's to a peak of +1.64 g's while lateral acceleration changed from -.13 g's to +.23 g within three seconds. The flight attendant in the forward jumpseat was making an announcement regarding the seatbelt sign and hit her head on the back of the jumpseat when the flight encountered turbulence. She reported that she saw a passenger in the rear of the cabin thrown against the ceiling and then back down to the floor and another passenger displaced from her seat hit her head on the overhead storage compartments. A passenger in the aft lavatory was thrown against the ceiling and wall and two additional passengers were displaced from their seats. The cabin crew contacted the flight crew to notify them of the injuries, and the flight crew arranged for paramedics to meet the airplane at the destination airport. Three passengers were transported to a local hospital. All were treated and released; one was diagnosed with a dislocated shoulder and a chipped bone.

Aircraft

Registration
N246LR
Reported as
Bombardier CL600 2D24 (900)
Category
Airplane
Serial number
15239
Built
2009
Airframe hours
10,018.5
Engines
General Electric CF34-8C5, 13,360 lbs thrust, turbo fanGeneral Electric CF34-8C5, 13,360 lbs thrust, turbo fan
Damage
No damage
Flight
Part 121
Operator
Mesa Airlines Inc
Registered owner
Mesa Airlines Inc
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · June 10, 2015
Departed
KPHX · Phoenix, AZ
Destination
KDSM · Des Moines, IA
Flight plan
IFR
Equipment
Electronic primary flight display, Onboard weather, Stall warning system, Angle of attack indicator, Auto-pilot, Data recorder, Electronic multifunction display

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, Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Last flight review
February 12, 2015
Seat
Left
Flight hours
11,800 total · 6,114 in this make and model · 8,345 as pilot in command · 186 in the last 90 days · 29 in the last 30 days · 11 in the last 24 hours
Role
Co-pilot
Age
25
Injuries
None
Certificates
Flight instructor, Airline transport, Commercial
Airplane ratings
Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
October 27, 2014
Seat
Right
Flight hours
1,564 total · 356 in this make and model · 547 as pilot in command · 160 in the last 90 days · 49 in the last 30 days · 7 in the last 24 hours

Weather

Conditions
Day
Turbulence
Unknown

Docket · 5

The files NTSB released with the investigation on April 8, 2016, on NTSB’s docket system: statements, records, photos and specialists’ reports. 25.1 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.