CEN13CA108

NTSB accident investigation · Piper PA-18-150 · Okaton, SD · December 11, 2012

Accident · No injuriesData collectionFinal report
Date
December 11, 2012, 09:00 local (15:00 UTC)
Place
Okaton, SD
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Takeoff
Aircraft
N3471ZPiper PA-18-150
Defining event
Takeoff: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed · report April 3, 2013
Report
Approved by Office Director
NTSB office
Central Region
Parties
FAA - Rapid City FSDO
FAA report
20121211027059A
Case key
85841

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 failure to perform an adequate preflight inspection of the airplane and obstruction of the aileron control system by snow and ice, which led to a loss of control during flight.

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.

Inspection: preflight inspectionPersonnel issues › Task performance · PilotPiper PA-18-150: 4 casesAll aircraft: 551 casesProbable cause
Flight control system: aileron control systemAircraft › Aircraft systems · Inadequate inspectionPiper PA-18-150: 2 casesAll aircraft: 45 casesProbable cause
Temp/humidity/pressure: conducive to structural icingEnvironmental issues › Conditions/weather/phenomena · Contributed to outcomePiper PA-18-150: 2 casesAll aircraft: 103 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 2 days before the accident, snow accumulated on the airplane’s wings while it was parked in an open front hangar. The day before the accident, the temperature was warmer, and the pilot believed that the snow melted and ran rearward to the aileron gap/hinge locations, re-freezing during the nighttime hours. On the day of the accident, the pilot was in a hurry to use the airplane to check his pastures and brushed the snow off of the wings but did not perform a thorough preflight check of the airplane, including checking freedom of movement of the ailerons. After takeoff, the airplane began turning to the left. The pilot attempted to correct the turn, but the airplane did not respond. When he looked out at the wings, he could see that the ailerons were not responding to control inputs as they should. As he was attempting to regain control, the airplane descended into trees, resulting in substantial damage to both wings, the fuselage, and tail surfaces. A postaccident examination of the airplane revealed no mechanical defects that were determined to have existed before the accident.

Factual narrative

The pilot reported that two days prior to the accident, snow accumulated on the wings of the airplane while it was in an open front hangar. The day prior to the accident the temperature was warmer and the pilot believed that the snow melted and ran rearward to the aileron gap/hinge locations, re-freezing during the nighttime hours. The day of the accident the pilot said he was in a hurry to use the airplane to check his pastures and brushed the snow off of the wings, but did not perform a thorough preflight check of the airplane and did not check freedom of movement of the ailerons. After takeoff, the airplane began turning to the left. The pilot said that he attempted to correct, but there was no response. When he looked out at the wings, he could see that the ailerons were not responding to control inputs as they should. As he was attempting to regain control, the airplane descended into trees. A postaccident examination of the airplane revealed no defects that were determined to have existed prior to the accident. The airplane sustained substantial damage to both wings, the fuselage and tail surfaces.

Aircraft

Registration
N3471Z
Reported as
Piper PA-18-150
Category
Airplane
Serial number
18-7291
Engine
Lycoming O-320 SERIES, 150 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Departed
PVT · Okaton, SD
Destination
PVT · Okaton, SD
Airport
PVT · Private airstrip, runway 09, grass/turf

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
54
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, With waivers/limitations
Seat
Front
Flight hours
2,000 total · 600 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
320° at 5 knots
Visibility
10 statute miles
Lowest ceiling
9,500 ft overcast
Temperature
19 °F, dew point 16 °F
Altimeter
29.85 inHg
Observed at
PHP, 37 nm away

Docket · 1

The files NTSB released with the investigation on January 16, 2013, on NTSB’s docket system: statements, records, photos and specialists’ reports. 102 KB 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 N3471Z · 1

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