ANC01LA112

NTSB accident investigation · Arctic S-1B2 · Wrangell, AK · August 11, 2001

Accident · No injuriesLimited investigationFinal report
Date
August 11, 2001, 13:15 local (21:15 UTC)
Place
Wrangell, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N61ATArctic S-1B2
Weather
Visual (VMC) · Day
Status
Completed · report February 20, 2002
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA-AL-JNU FSDO 05
Case key
53032

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 inadequate evaluation of the weather conditions during a downwind landing at a remote lake. Factors in the accident were a downdraft, rough/uneven terrain, and the pilot's inadequate in-flight planning/decision(s).

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

In flight encounter with weatherApproach - vfr pattern - final approach
Weather evaluation - inadequatePilot in commandCause
Weather condition - downdraftFactor
In-flight planning/decision - inadequatePilot in commandFactor
In flight collision with terrain/waterApproach - vfr pattern - final approach
Terrain condition - rough/unevenFactor

Analysis

The private certificated pilot was landing at a remote lake in a float-equipped airplane. The pilot reported he was landing toward the south because it was the only suitable approach path into the lake. The wind was blowing from the north at 15 knots. During the landing approach, the pilot said he encountered a downdraft, and the airplane began to descend below the planned approach path. The pilot turned the airplane into the wind, but he said he was unable to out-climb the downdraft. The airplane then collided with trees and rocks, and received damage to wings, fuselage, and engine.

Factual narrative

On August 11, 2001, about 1315 Alaska daylight time, a float-equipped Arctic Aircraft Company Inc., S-1B2 airplane, N61AT, sustained substantial damage while landing at a remote lake, about 21 miles north of Wrangell, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight when the accident occurred. The airplane was operated by the pilot. The private certificated pilot, and the sole passenger, were not injured. Visual meteorological conditions prevailed. A VFR flight plan was filed from Petersburg, Alaska, to Alpine Lake, to Petersburg. The flight originated at the Lloyd Roundtree Seaplane Facility, Petersburg, about 1245.

During a telephone conversation with a National Transportation Safety Board (NTSB) investigator, on August 13, the pilot reported that he was landing toward the south at the lake. He said the approach toward the south is the only suitable approach path into the lake, and the wind was blowing from the north at 15 knots. When the airplane was on final approach, it encountered a downdraft, and began to descend below the planned approach path. The pilot turned the airplane into the wind, but he said he was unable to out-climb the downdraft. The airplane then collided with trees and rocks, and received damage to wings, fuselage, and engine.

Aircraft

Registration
N61AT
Reported as
Arctic S-1B2
Category
Airplane
Serial number
1012
Airframe hours
1,857
Engine
Lycoming O-320-B2B, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
David W. Cushing
Airworthiness certificate
Standard, Normal
Last inspection
Annual · December 7, 2000 · 45 hours before
Departed
63A · Petersburg, AK
Destination
Wrangell, AK
Flight plan
VFR

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
52
Injuries
None
Certificate
Private
Airplane ratings
Single-engine sea, Single-engine land
Medical
Class 1, Valid Medical--w/ waivers/lim
Last flight review
July 27, 2001
Seat
Front
Flight hours
801 total · 124 in this make and model · 800 as pilot in command · 17 in the last 90 days · 12 in the last 30 days · 0 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
325° at 15 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
61 °F
Altimeter
30.13 inHg

Other investigations on N61AT · 1

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