- Date
- July 28, 2001, 15:00 local (20:00 UTC)
- Place
- Edmore, ND
- Injuries
- 1 minor
- Damage
- Substantial damage
- Phase of flight
- Takeoff
- Aircraft
- N4361SAir Tractor AT-301
- Weather
- Visual (VMC) · Day
- Status
- Completed · report January 23, 2002
- Report
- Approved by Office Director
- Parties
- FAA-Fargo, North Dakota FSDO
- FAA report
- 20010728021479A
- Case key
- 53272
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 incorrect installation of the wheel assembly bolts by maintenance personnel resulting in the stripped bolt threads and ultimate failure of the wheel, and directional control not possible by the pilot. A factor was the ditch
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
The airplane impacted a ditch and nosed over during takeoff from a road. Examination of the wreckage revealed that the right outboard wheel half, right tire, and right tire inner tube had separated from the airframe. No other anomalies were found that could be associated with a pre-impact condition. Three of the right wheel through bolts were recovered from the accident scene. Two of the recovered bolts had stripped threads and a third was fractured in the threaded portion of the bolt. The left wheel was examined and was found intact. Seven of the through bolts that hold the left wheel halves together were found to have been over-torqued. The torque readings were from 125 to 175 inch-pounds on these bolts. The specified torque as printed on the wheel is 90 inch-pounds. The remaining two bolts were found to be stripped. One of the through bolts was found to be a coarse thread bolt. The bolts specified for attaching the wheel halves are AN4 fine thread bolts.
Factual narrative
On July 28, 2001, at about 1500 central daylight time, an Air Tractor AT-301, N4361S, piloted by a commercial pilot, was substantially damaged when it impacted a ditch and nosed over during takeoff from a road near Edmore, North Dakota. The 14 CFR Part 137 Aerial application flight was operating in visual meteorological conditions and was not on a flight plan. The pilot received minor injuries. The local flight was originating at the time of the accident.
Post accident examination of the wreckage revealed that the right outboard wheel half, right tire, and right tire inner tube had separated from the airframe. No other anomalies were found that could be associated with a pre-impact condition.
Three of the right wheel through bolts were recovered from the accident scene. Two of the recovered bolts had stripped threads and the third was fractured in the threaded portion of the bolt. The left wheel was examined and was found intact. Seven of the through bolts that hold the left wheel halves together were found to have been over-torqued. The torque readings were from 125 to 175 inch-pounds on these bolts. The specified torque as printed on the wheel is 90 inch-pounds. The remaining two bolts were found to be stripped. One of the through bolts was found to be a coarse thread bolt. The bolts specified for attaching the wheel halves are AN4 fine thread bolts.
Aircraft
- Registration
- N4361S
- Reported as
- Air Tractor AT-301
- Category
- Airplane
- Serial number
- 301-0041
- Airframe hours
- 5,000
- Engine
- P&W R-1340-AN1, 600 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Aerial application · Part 137
- Registered owner
- Mark D. Brekke
- Airworthiness certificate
- Special, Restricted (Special)
- Last inspection
- Annual · May 20, 2001 · 310 hours before
- Departed
- Edmore, ND
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
- 45
- Injuries
- Minor
- Certificate
- Commercial
- Airplane ratings
- Single-engine land, Single-engine sea
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Last flight review
- May 5, 2000
- Seat
- Center
- Flight hours
- 3,010 total · 900 in this make and model · 3,010 as pilot in command · 360 in the last 90 days · 250 in the last 30 days · 7 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 140° at 7 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 77 °F, dew point 61 °F
- Altimeter
- 30.01 inHg
- Observed at
- DVL, 25 nm away
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.