ANC18CA017

NTSB accident investigation · Piper PA 18-125 · Nikolai, AK · November 29, 2017

Accident · No injuriesData collectionFinal report
Date
November 29, 2017, 12:02 local (21:02 UTC)
Place
Nikolai, AK
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N1386APiper PA 18-125
Defining event
Landing: Nose over/nose down
Weather
Visual (VMC) · Day
Status
Completed · report May 14, 2018
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
Federal Aviation Administration
FAA report
20171129022329A
Case key
96523

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 improper decision to contact an unsuitable landing surface, which resulted in a nose-over.

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.

Runway/land/takeoff/taxi surface: snow/slush/ice covered surfaceEnvironmental issues › Physical environment · Decision related to conditionPiper PA-18-125: 1 caseAll aircraft: 219 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 he had completed one high- and two low-reconnaissance flights over the snow-covered runway in his tundra-tire-equipped, tailwheel airplane. Before landing, he intended to fly a low pass and drag the main landing gear along the surface of the runway to determine the depth of the snow. He said that, as the main landing gear wheels touched down atop the frozen layer of crusty snow, the wheels broke through, and the airplane's tail began to rise. In an effort to prevent a nose-over, he applied full power, but the airplane subsequently nosed over. The airplane sustained substantial damage to the rudder and both left and right lift struts. The pilot reported that there were no preaccident mechanical malfunctions or failures that would have precluded normal operation.

Factual narrative

The pilot said that he had completed one high and two low reconnaissance flights over the snow-covered runway in his tundra tire-equipped, tailwheel airplane. Prior to landing, he intended to fly a low pass and drag the main landing gear along the surface of the runway to determine the depth of the snow, a maneuver commonly known as dragging the landing site. He said that as the main landing gear wheels touched down atop the frozen layer of crusty snow, the wheels broke through, and the airplane's tail began to rise. In an effort to prevent a nose over, he applied full power, but the airplane subsequently nosed over, sustaining substantial damage to the rudder and both left and right lift struts. The pilot stated there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation. In the recommendation section of the NTSB Accident/Incident Reporting Form 6120.1, the pilot stated that the accident may have been prevented if he would have utilized a flatter approach with increased airspeed similar to a glassy water approach while dragging the airstrip.

Aircraft

Registration
N1386A
Reported as
Piper PA 18-125 (125)
Category
Airplane
Serial number
18-1219
Built
1951
Airframe hours
4,321
Engine
Lycoming O-320 SERIES, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Public aircraft · Public use
Operator
State Of Alaska
Registered owner
State Of Alaska
Airworthiness certificate
Standard, Normal
Last inspection
Annual · July 6, 2017
Departed
PAMC · McGrath, AK
Destination
PALH · Anchorage, AK
Flight plan
Company VFR
Airport
8KA · Tatitna
Equipment
Handheld GPS, Satellite tracking device

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
43
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 14, 2017
Seat
Front
Restraint
3-point
Flight hours
8,200 total · 7,600 in this make and model · 7,900 as pilot in command · 80 in the last 90 days · 20 in the last 30 days · 4.5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
10,000 ft broken
Temperature
3 °F, dew point -2 °F
Altimeter
28.97 inHg
Observed at
PAMC, 54 nm away

Docket · 1

The files NTSB released with the investigation on April 4, 2018, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.8 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 N1386A · 3

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