WPR23LA217

NTSB accident investigation · Air Tractor AT-502B · Bakersfield, CA · June 5, 2023

Accident · Minor injuriesClass 4 · LimitedFinal report
Date
June 5, 2023, 16:00 local (23:00 UTC)
Place
Bakersfield, CA
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Takeoff
Aircraft
N6174WAir Tractor AT-502B
Defining event
Takeoff: Collision during takeoff/land
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 4 - Basic report with no Prelim publish
NTSB office
Western Pacific Region
Parties
FAA
FAA report
20230605008999A
Case key
192320

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 improper use of flaps during the takeoff sequence which resulted in a runway overrun and collision with trees.

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.

Aircraft capability: climb capabilityAircraft › Aircraft oper/perf/capability · Capability exceededAir Tractor AT-502B: 3 casesAll aircraft: 183 cases
Performance/control parameters: configurationAircraft › Aircraft oper/perf/capability · Incorrect use/operationAir Tractor AT-502B: 1 caseAll aircraft: 80 cases
Object/animal/substance: tree(s)Environmental issues › Physical environment · Effect on equipmentAir Tractor AT-502B: 3 casesAll aircraft: 933 cases

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

According to the pilot, he configured the flaps to 20° while he waited for the aerial application airplane to take on 50 gallons of fuel and 400 pounds of fertilizer. He taxied onto the 2,600 ft long asphalt runway, for his 4th aerial application flight of the day. The pilot applied brakes and full power before he released the brakes to initiate the takeoff roll. About 1,300 ft down the runway, the airplane remained on the ground. The pilot applied back pressure to the control stick and the airplane ascended about 10 feet above ground level. The airplane would not climb, and the pilot applied full flaps. The airplane subsequently settled back onto the remaining 1/3rd of the runway. The pilot reported that he did not observe any cockpit instrument cautions or warnings illuminated. The airplane overran the departure end of the runway and collided with trees. The manufacturer’s airplane flight manual (AFM) contains a warning that stated, when taking off from a short-field runway, full flaps should not be used during the takeoff sequence. The use of full flaps creates large amounts of drag, lengthens the ground roll, and impairs climb performance. The pilot submitted an NTSB Form 6120.1, Pilot Aircraft Accident Report, but did not include pages 9 and 10, which encompassed the pilot’s narrative, and his assertion regarding a mechanical malfunction during the sequence of events.

Aircraft

Registration
N6174W
Reported as
Air Tractor AT-502B
Category
Airplane
Serial number
502B-0351
Built
1996
Airframe hours
8,699
Engine
P&W PT6A, 500 horsepower, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
Wheeler Ridge Aviation Inc, doing business as Wheeler Ridge Aviation Inc
Registered owner
Wheeler Ridge Aviation Inc
Airworthiness certificate
Special, Restricted (Special)
Last inspection
100 hour · April 1, 2023
Airport
0 · Company Airstrip, runway 27, 2,500 × 50 ft, asphalt
Equipment
Unknown

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
60
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 2, With waivers/limitations
Last flight review
March 7, 2022
Seat
Front
Flight hours
5,847.1 total · 770.2 in this make and model · 5,847.1 as pilot in command · 100 in the last 90 days · 33 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
330° at 15 knots
Visibility
7 statute miles
Lowest ceiling
None
Temperature
81 °F, dew point 52 °F
Altimeter
29.71 inHg
Observed at
KBFL, 21 nm away
METAR
KBFL 052254Z 33015KT 7SM CLR 27/11 A2971 RMK AO2 SLP054 T02720111

Docket · 6

The files NTSB released with the investigation on April 4, 2024, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.5 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.