CEN15IA200

NTSB incident investigation · Air Tractor AT 402A · Brickeys, AR · April 4, 2015

Incident · No injuriesIncident investigationFinal report
Date
April 4, 2015, 14:30 local (19:30 UTC)
Place
Brickeys, AR
Injuries
1 uninjured
Damage
Minor damage
Phase of flight
Maneuvering
Aircraft
N623LAAir Tractor AT 402A
Defining event
Maneuvering-low-alt flying: Flight control sys malf/fail
Weather
Visual (VMC) · Day
Status
Completed · report December 14, 2015
Report
Approved by Office Director
NTSB office
Central Region
FAA report
20150404003849I
Case key
91047

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

On this page

Probable cause

The in-flight separation of the attachment hardware at the elevator control pushrod due to maintenance personnel's improper reinstallation of the attachment hardware.

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.

Flight control system: elevator control systemAircraft › Aircraft systems · Incorrect service/maintenanceAir Tractor AT-402A: 1 caseAll aircraft: 74 casesProbable cause
Maintenance: installationPersonnel issues › Task performance · Maintenance personnelAir Tractor AT-402A: 1 caseAll aircraft: 371 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, during an agricultural application pass, the elevator control felt abnormal. The pilot chose to return to the airport and noted that the elevator control was unresponsive. The pilot attempted to maintain pitch control by using the elevator trim, but turbulence made this difficult. During the off-field landing, the airplane's nose pitched down. The pilot countered with nose-up trim, and the airplane stalled and then impacted the ground, which resulted in minor damage to the propeller. A postincident examination revealed that the attachment hardware, including the bolt and nut, at the elevator pushrod had separated. Maintenance had been performed on the elevator control pushrod about 20 hours before the incident flight, and the bolt and nut would have been removed and reinstalled during this maintenance. It is likely that maintenance personnel did not properly reinstall the attachment hardware after performing the maintenance.

Factual narrative

On April 4, 2015, about 1430 central daylight time, an Air Tractor AT-402A, N623LA, sustained minor damage during a forced landing to a field near Brickeys, Arkansas. The commercial pilot was not injured. The aerial application flight, owned and operated by Taylor Air Service, LLC., was being conducted under the provisions of 14 Code of Federal Regulations Part 137 without a flight plan. Visual meteorological conditions prevailed at the time of the incident. The local flight departed Dawson's Airport (15AR), Brickeys, Arkansas, about 1230. The pilot reported that during an aerial application pass the elevator control felt abnormal. As he completed the pass he pulled up and detected that the elevator was not responding. The pilot elected to return to the airport and the elevator control continued to be unresponsive. The pilot attempted to maintain pitch control through the use of the elevator trim but turbulence and power changes made this difficult. During an off field landing, the airplane nose pitched down. The pilot countered with nose up trim and the airplane stalled. There was minor damage to the propeller during the impact with the ground. A post incident examination established that the attachment hardware, including the bolt and nut, was missing from the forward end of the #2 elevator control pushrod. The bolt was located in the airplane in the lower fuselage; however, the nut was not located. About 20 hours prior to the incident flight, maintenance had been performed on the forward rod end bearing on the #2 pushrod. The bolt and nut would have been removed and reinstalled during this maintenance. It is not known if original hardware was used or if the hardware was replaced during this maintenance.

Aircraft

Registration
N623LA
Reported as
Air Tractor AT 402A
Category
Airplane
Serial number
402A-1127
Built
2000
Airframe hours
6,476.1
Engine
Pratt & Whitney PT6-11AE, 550 horsepower, turbo prop
Damage
Minor damage
Flight
Aerial application · Part 137
Operator
Taylor Air Service LLC
Registered owner
Taylor Air Service LLC
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · February 3, 2015
Departed
15AR · Brickeys, AR
Destination
15AR · Brickeys, AR
Airport
15AR · Dawson's Airport
Equipment
Stall warning system

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
53
Injuries
None
Certificates
Private, Airline transport, Commercial
Airplane ratings
Single-engine land, Single-engine sea, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
January 8, 2014
Seat
Single
Restraint
3-point
Flight hours
25,201 total · 22.2 in this make and model · 20,785 as pilot in command · 75 in the last 90 days · 75 in the last 30 days · 0.8 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
350° at 10 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
59 °F, dew point 32 °F
Altimeter
30.36 inHg
Observed at
UTA, 13 nm away

Docket · 5

The files NTSB released with the investigation on November 12, 2015, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.2 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.

Other investigations on N623LA · 1

Matched to the same aircraft by N-number and date.