CHI08CA257

NTSB accident investigation · Air Tractor AT-400A · Luverne, MN · August 16, 2008

Accident · No injuriesData collectionFinal report
Date
August 16, 2008, 10:00 local (15:00 UTC)
Place
Luverne, MN
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N7307WAir Tractor AT-400A
Defining event
Maneuvering-low-alt flying: Loss of engine power (total)
Weather
Visual (VMC) · Day
Status
Completed · report September 26, 2008
Report
Approved by Office Director
Parties
MSP FSDO
FAA report
20080816846649A
Case key
68875

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The failure of the compressor turbine blades which resulted in the loss of power. Factors associated with the accident were the low altitude and the trees.

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.

Object/animal/substance: tree(s)Environmental issues › Physical environment · Contributed to outcomeAir Tractor AT-400A: 1 caseAll aircraft: 933 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 accident occurred during an aerial application flight. The pilot reported she had sprayed approximately 40 acres when the engine began making a "popping" sound with a higher pitched whistle. She reported she pulled back on the elevator control to gain as much altitude as possible and began looking for a place to land. She stated that while looking out the right side of the airplane, she noticed flames coming from the right side exhaust stack. The pilot determined she was not able to land on the country road, so she decided to try and fly between a couple of trees to land in an open field. She stated the airplane touched down prior to the trees and it spun to the right, impacting one of the trees with the left wing. Inspection of the engine revealed that all of the compressor turbine blades were damaged with most of them having broken off. Damage was also present to the outlet side of the compressor turbine guide vanes.

Factual narrative

On August 16, 2008, at 1000 central daylight time, an Air Tractor AT-400A, N7307W, operated by Wilbur-Ellis Air LLC, collided with a tree during an off airport forced landing in Luverne, Minnesota. The commercial pilot was not injured. The airplane sustained substantial damage to the left wing. The aerial application flight was operating under Title 14 Code of Federal Regulations Part 137. Visual meteorological conditions prevailed and no flight plan was filed. The local flight originated from the Luverne Municipal Airport (LYV), Luverne, Minnesota, at 0950. The pilot reported she had sprayed approximately 40 acres when the engine began making a "popping" sound with a higher pitched whistle. She reported she pulled back on the elevator control to gain as much altitude as possible and began looking for a place to land. She stated that while looking out the right side of the airplane, she noticed flames coming from the right side exhaust stack. The pilot determined she was not able to land on the country road, so she decided to try and fly between a couple of trees to land in an open field. She stated the airplane touched down prior to the trees and it spun to the right, impacting one of the trees with the left wing. Inspection of the engine revealed that all of the compressor turbine blades were damaged with most of them having broken off. Damage was also present to the outlet side of the compressor turbine guide vanes.

Aircraft

Registration
N7307W
Reported as
Air Tractor AT-400A
Category
Airplane
Serial number
400A-613
Engine
Pratt & Whitney Canada PT6A-20, turbo prop
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
Wilbur-Ellis Air LLC
Airworthiness certificate
Special, Restricted (Special)
Departed
LYV · Luverne, MN
Destination
LYV

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

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
35
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Without waivers/limitations
Flight hours
3,656 total · 219 in this make and model · 3,167 as pilot in command · 344 in the last 90 days · 181 in the last 30 days · 8 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
260° at 6 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
72 °F, dew point 63 °F
Altimeter
30.27 inHg
Observed at
FSD

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.