CEN21LA362

NTSB accident investigation · Air Tractor AT-502B · Topeka, KS · August 6, 2021

Accident · No injuriesClass 4 · LimitedFinal report
Date
August 6, 2021, 08:48 local (13:48 UTC)
Place
Topeka, KS · Bean field near Topeka, KS
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N502CPAir Tractor AT-502B
Defining event
Maneuvering-low-alt flying: Fuel exhaustion
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 4 - Basic report with no Prelim publish
NTSB office
Central Region
Parties
Hartzell Propeller, FAA Wichita FSDO, Air Tractor, Pratt & Whitney Canada, Transportation Safety Board of Canada
FAA report
20210806011439A
Case key
103654

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 pilot’s decision to continue low-level aerial application flight maneuvers after the low fuel warning light illuminated, which resulted in a partial loss of engine power due to fuel exhaustion.

Findings · 4

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.

Fluids: fuelAircraft › Fluids/misc hardware · Fluid managementAir Tractor AT-502B: 4 casesAll aircraft: 1,695 casesProbable cause
Fuel systemAircraft › Aircraft systems · Incorrect use/operationAir Tractor AT-502B: 2 casesAll aircraft: 181 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 commercial pilot reported that before the aerial application flight, he added Jet A fuel to both wing tanks for a total of 150 gallons of fuel onboard. While flying low-level over a field on the third load, the pilot noticed a change in engine power. He maneuvered the airplane out of the field and the engine steadily lost power. The pilot tried to advance the power forward with no change and the airspeed and altitude decreased. The pilot performed a forced landing to a bean field. During the landing, the airplane bounced, slid across a road, and then came to rest upright. The airplane sustained substantial damage to the fuselage and the right wing. The property owner of the bean field reported that he helped the pilot add about 9 gallons of red die automotive diesel fuel to the left fuel tank and about 5 gallons of the fuel to the right fuel tank after the accident. The pilot reported that the low fuel warning light illuminated about five minutes before the partial loss of engine power, yet the pilot continued with the low-level aerial application maneuvers. When the low fuel warning light illuminates, the airplane flight manual states to, “fly straight and level and monitor fuel gauges” and “land as soon as practical.” The operator reported that there were no preimpact mechanical malfunctions or failures with the airframe and engine that would have precluded normal operation.

Aircraft

Registration
N502CP
Reported as
Air Tractor AT-502B
Category
Airplane
Serial number
502B2632
Built
2008
Airframe hours
4,648.1
Engine
Pratt & Whitney Canada PT6A-34AG, 750 horsepower, turbo prop
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
McElwain Sprayers, LLC, doing business as McElwain Sprayers, LLC
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · June 1, 2021
Departed
K59 · Atchison, KS
Destination
69K · Wamego, KS
Equipment
Stall warning system, ADS-B

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
25
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land, Single-engine sea
Instrument ratings
Airplane
Medical
Class 2, Without waivers/limitations
Last flight review
June 5, 2021
Seat
Single
Restraint
4-point
Flight hours
2,470.7 total · 473 in this make and model · 2,452.9 as pilot in command · 563.3 in the last 90 days · 314.2 in the last 30 days · 11.5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
80° at 5 knots
Visibility
9 statute miles
Lowest ceiling
None
Temperature
72 °F, dew point 64 °F
Altimeter
30.03 inHg
Observed at
KTOP, 11 nm away
METAR
KTOP 061353Z 08005KT 9SM CLR 22/18 A3003 RMK AO2 SLP159 T02220178

Docket · 5

The files NTSB released with the investigation on September 15, 2021, on NTSB’s docket system: statements, records, photos and specialists’ reports. 88.5 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.