CEN23LA377

NTSB accident investigation · Air Tractor AT-502 · Great Bend, ND · August 15, 2023

Accident · No injuriesClass 3 · LimitedFinal report
Date
August 15, 2023, 10:45 local (15:45 UTC)
Place
Great Bend, ND
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N9082CAir Tractor AT-502
Defining event
Landing: Hard landing
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
Transportation Safety Board of Canada, Federal Aviation Administration
Case key
192923

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 pilot’s hard landing on a road and subsequent loss of control, resulting in the airplane impacting a ditch.

Findings · 3

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.

Action: incorrect action performancePersonnel issues › Action/decision · PilotAir Tractor AT-502: 4 casesAll aircraft: 1,386 casesProbable cause
Performance/control parameters: directional controlAircraft › Aircraft oper/perf/capability · Not attained/maintainedAir Tractor AT-502: 6 casesAll aircraft: 3,958 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 pilot reported that he had completed an aerial application with the airplane and was in a turn when the engine lost power. The pilot said he advanced the power lever to full but there was no engine response. The pilot attempted a forced landing on a nearby county road. The airplane landed hard on the road surface, bounced back in the air and floated some distance before settling back on the road. The airplane then veered off the road, went through a ditch, and came to rest in an adjacent farm field. The airplane sustained substantial damage to the left and right tubular clusters where the main landing gear attach. The pilot later reported that, after reviewing speed and altitude data from one of the airplane’s track logs, his recollection of the event did not match what the data showed. He stated that, “The log shows no loss of airspeed that would indicate a loss of power before the initial impact with the ground.” He went on to state that he was no longer confident that his original recollection that there was a power loss was accurate and that this incident was likely caused by pilot error. An examination of the airplane’s fuel control unit (FCU) and fuel pump showed black material in the vicinity of the Py orifice inlet. The manufacturer identified the material as soft debris similar to fluorocarbon and most likely from the packing (O-ring) used on the P3 air inlet fitting. The debris’ size and location did not completely obstruct the inlet and would have allowed for air passage into the FCU, hence not hindering its operability. A bench test of the fuel control unit and fuel pump showed the unit and pump performed normally. No other preaccident failures or malfunctions with the airplane were found that would have precluded normal operations.

Factual narrative

On August 15, 2023, about 1045 central daylight time, an Air Tractor Inc AT-502, N9082C, was substantially damaged when it was involved in an accident near Great Bend, North Dakota. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 agricultural flight. The pilot reported that he had completed an aerial application with the airplane and was in a turn when the engine lost power. The pilot said he advanced the power lever to full but there was no engine response. The pilot attempted a forced landing on a nearby county road. The airplane landed hard on the road surface, bounced back in the air and floated some distance before settling back on the road. The airplane then veered off the road, went through a ditch, and came to rest in an adjacent farm field. The pilot recalled that he heard the engine noise tone and volume change as the airplane slowed. He also remembered seeing the torque needle reducing to near 500 and falling. He said he didn’t see if it eventually reached zero, but it did not increase as he advanced the power lever. At that point his focus was getting the airplane on the ground safely. In a subsequent statement, the pilot reported that after reviewing speed and altitude data from one of the airplane’s track logs, his recollection of the event didn’t match what the data showed. He stated that, “The log shows no loss of airspeed that would indicate a loss of power before the initial impact with the ground.” He went on to state that he was no longer confident that his original recollection that there was a power loss was accurate. “With this new information it would appear to me that this incident was likely caused by pilot error. It has become evident to me that my memory of the event in that moment are patchy, scrambled, and likely inaccurate.” The airplane sustained damage to the propeller, engine, and the main landing gear. Both fuel tank gauges showed half full of fuel. A postaccident examination of the airplane showed substantial damage to the left and right tubular clusters where the main landing gear attach. The airplane’s fuel control unit (FCU) and fuel pump were retained for further examination. An examination of the FCU showed black material in the vicinity of the Py orifice inlet. The manufacturer identified the material as soft debris similar to fluorocarbon and most likely from the packing (O-ring) used on the P3 air inlet fitting. Per the manufacturer, the debris’ size and location did not completely obstruct the inlet and would have allowed for air passage into the FCU, hence not hindering its operability. A bench test of the fuel control unit and fuel pump showed the unit and pump performed normally. No other preaccident mechanical failures or malfunctions were found with the airplane that would have precluded normal operations.

Aircraft

Registration
N9082C
Reported as
Air Tractor AT-502
Category
Airplane
Serial number
502-0193
Built
1992
Airframe hours
5,062
Engine
P&W PT6A-34AG, 750 horsepower, turbo prop
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
Dakota Air Spray
Registered owner
Wilbur-Ellis Air LLC
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · August 9, 2023 · 132 hours before
Departed
BWP · Wahpeton, ND
Destination
BWP · Wahpeton, 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
39
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
March 24, 2023
Seat
Single
Restraint
5-point
Flight hours
1,949 total · 477 in this make and model · 1,940 as pilot in command · 449 in the last 90 days · 200 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
240° at 12 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
75 °F, dew point 63 °F
Altimeter
30.05 inHg
Observed at
KBWP, 8 nm away
METAR
KBWP 151535Z AUTO 24012KT 10SM CLR 24/17 A3005 RMK AO2

Docket · 9

The files NTSB released with the investigation on May 9, 2024, on NTSB’s docket system: statements, records, photos and specialists’ reports. 7.7 MB in all.