CEN12LA236

NTSB accident investigation · Ayres S2R-T15 · Lakin, KS · April 9, 2012

Accident · Serious injuriesLimited investigationFinal report
Date
April 9, 2012, 09:30 local (14:30 UTC)
Place
Lakin, KS
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N64DXAyres S2R-T15
Defining event
Maneuvering-low-alt flying: Aerodynamic stall/spin
Weather
Visual (VMC) · Day
Status
Completed · report October 9, 2012
Report
Approved by Office Director
NTSB office
Central Region
Parties
Federal Aviation Administration - Wichita FSDO
FAA report
20120409006589A
Case key
83339

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 did not maintain sufficient airspeed while maneuvering, which resulted in an aerodynamic stall at a low altitude.

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.

Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedAyres S2R-T15: 1 caseAll aircraft: 1,681 casesProbable cause
Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotAyres S2R-T15: 3 casesAll aircraft: 9,295 casesProbable cause
Object/animal/substance: tower/antenna (incl guy wires)Environmental issues › Physical environment · Contributed to outcomeAyres S2R-T15: 1 caseAll aircraft: 55 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

The accident occurred during an aerial-application flight as the pilot maneuvered around a tower. The pilot reported that he had the tower in sight as he maneuvered toward the field being sprayed, and during that turn, the airplane began to shudder as if entering an aerodynamic stall. The pilot attempted to recover from the aerodynamic stall by reducing the elevator input, but the airplane continued to descend rapidly and collided with a tower guy-wire. The pilot stated that there were no preimpact mechanical malfunctions or failures that would have precluded normal operation of the airplane.

Factual narrative

On April 9, 2012, at 0930 central daylight time, an Ayres Corporation model S2R-T15 airplane, N64DX, was substantially damaged when it collided with a tower guy-wire during an aerial-application flight near Lakin, Kansas. The pilot sustained serious injuries. The airplane was registered to and operated by Tri Rotor Spray & Chemical, under the provisions of 14 Code of Federal Regulations Part 137 without a flight plan. Day visual meteorological conditions prevailed for the local flight that originated from Lakin Airport (36K), Lakin, Kansas, about 0920. The pilot reported that he had the tower in sight as he maneuvered back toward the field being sprayed. While in the turn, the airplane began to shudder as if entering an aerodynamic stall. The pilot reduced elevator input in an attempt to recover from the aerodynamic stall as he continued the turn to avoid the tower. He stated that the airplane was descending rapidly when the right wing collided with a tower guy-wire. The airplane subsequently collided with the terrain. The pilot reported that there were no preimpact mechanical malfunctions or failures that would have precluded normal operation of the airplane. The closest weather observing station was at the Garden City Regional Airport (KGCK), located about 25 miles east of the accident site. At 0930, the KGCK automated surface observing system reported the following weather conditions: wind 160 degrees at 7 knots; visibility 5 miles with mist; scattered clouds at 800 feet above ground level (agl) and an overcast ceiling at 1,500 feet agl; temperature 13 degrees Celsius; dew point 12 degrees Celsius; altimeter setting 30.14 inches of mercury.

Aircraft

Registration
N64DX
Reported as
Ayres S2R-T15
Category
Airplane
Serial number
T15-040
Airframe hours
6,810
Engine
Pratt & Whitney PT6A-15AG, 750 horsepower, turbo prop
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
Tri Rotor Spray & Chemical
Registered owner
Tri Rotor Spray & Chemical
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · March 1, 2012
Departed
36K · Lakin, KS
Destination
36K · Lakin, KS

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
58
Injuries
Serious
Certificate
Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
April 2, 2010
Seat
Center
Flight hours
3,000 total · 100 in this make and model · 2,900 as pilot in command

Weather

Conditions
Visual (VMC) · Day
Wind
160° at 7 knots
Visibility
5 statute miles
Lowest ceiling
1,500 ft overcast
Temperature
55 °F, dew point 54 °F
Altimeter
30.13 inHg
Observed at
KGCK, 25 nm away

Docket · 3

The files NTSB released with the investigation on August 2, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.1 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.