CEN10LA218

NTSB accident investigation · Saab-Scania Saab 340B · Bradley, IL · April 6, 2010

Accident · Serious injuriesLimited investigationFinal report
Date
April 5, 2010, 19:30 local (Apr 6, 2010, 00:30 UTC)
Place
Bradley, IL
Injuries
1 serious, 30 uninjured
Damage
No damage
Phase of flight
Enroute
Aircraft
N437XJSaab-Scania Saab 340B
Defining event
Enroute-cruise: Turbulence encounter
Weather
Instrument (IMC) · Dusk
Status
Completed · report April 28, 2011
Report
Approved by Office Director
NTSB office
Central Region
Parties
Minneapolis FSDO
FAA report
20100405050349A
Case key
75830

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

The flightcrew's encounter with convectively induced turbulence associated with a convective cloud during the flight.

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.

TurbulenceEnvironmental issues › Conditions/weather/phenomena · Effect on personnelAll aircraft: 92 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

The airplane entered a cumulus or convective cloud system and encountered moderate to severe turbulence as it approached its destination. The single flight attendant in the cabin hit her head on the cabin roof and then fell, fracturing her tail bone. The flight attendant was able to complete her duties and sought medical assistance after landing.

Factual narrative

On April 5, 2010, about 1930 central daylight time, a Saab 340B, N437XJ, operated by Mesaba Airlines, Inc., as Delta Connection Flight 3271, and piloted by an airline transport pilot, encountered turbulence while in cruise flight near Bradley, Illinois. The sole flight attendant received serious injuries when she fell during the turbulence encounter. There was no damage to the airplane and no injuries to the other crew or passengers on the flight. The 14 Code of Federal Regulations Part 121 flight was operating in instrument meteorological conditions and was on an instrument flight rules flight plan. The airplane had departed from the Detroit Metropolitan Wayne County Airport at 1827 and was en route to the General Downing - Peoria International Airport when the event occurred. The airplane was approaching its destination airport and the flight crew was attempting to make course corrections to avoid entering cumulus clouds on the airplane's flight path. At this point, the seatbelt sign was illuminated and the passengers were seated with their seat belts fastened. As the flight crew deviated around clouds, a buildup of clouds was unavoidable and the airplane entered the clouds. As the airplane entered the clouds, a brief turbulence encounter was experienced. At this time the flight attendant had just completed collecting garbage after the beverage service and was preparing to sit in her seat. The flight attendant stated that she was raised up off of the floor and her head hit the cabin roof. She was thrown back down to the floor and landed on her buttocks. The flight attendant was able to complete her duties with pain, and sought medical attention after the flight. It was later determined that she suffered a broken tail bone. The severity of the turbulence encountered was described as moderate by the operator and severe by the flight attendant.

Aircraft

Registration
N437XJ
Reported as
Saab-Scania Saab 340B
Category
Airplane
Serial number
340B437
Engines
GE CT7-SER, 1,600 horsepower, turbo propGE CT7-SER, 1,600 horsepower, turbo prop
Damage
No damage
Flight
Part 121
Operator
Mesaba Aviation Inc, doing business as Delta Connection
Registered owner
Lambert Leasing Inc
Airworthiness certificate
Standard, Normal
Departed
DTW · Detroit, MI
Destination
PIA · Peoria, IL
Flight plan
IFR

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
34
Injuries
None
Certificate
Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
June 7, 2009
Seat
Left
Flight hours
7,800 total · 7,000 in this make and model · 53 in the last 90 days · 53 in the last 30 days · 5 in the last 24 hours
Role
Co-pilot
Age
28
Injuries
None
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Last flight review
July 23, 2009
Seat
Right
Flight hours
1,320 in this make and model · 130 in the last 90 days · 54 in the last 30 days · 5 in the last 24 hours

Weather

Conditions
Instrument (IMC) · Dusk
Wind
140° at 7 knots
Visibility
10 statute miles
Lowest ceiling
6,000 ft broken
Temperature
70 °F, dew point 59 °F
Altimeter
29.78 inHg
Observed at
PIA, 90 nm away

Docket · 2

The files NTSB released with the investigation on February 1, 2011, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.1 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.