ANC09LA018

NTSB accident investigation · Cessna 172N · Atmautluak, AK · February 7, 2009

Accident · Minor injuriesLimited investigationFinal report
Date
February 7, 2009, 09:45 local (13:45 UTC)
Place
Atmautluak, AK
Injuries
4 minor
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N5246DCessna 172N
Defining event
Approach-VFR go-around: Aerodynamic stall/spin
Weather
Visual (VMC) · Day
Status
Completed · report July 28, 2009
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA, Anchorage Flight Standards District Office
FAA report
20090207025019A
Case key
73345

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's failure to maintain adequate airspeed while landing in gusty winds, which resulted in an aerodynamic stall; his improper aircraft weight calculations; and his operation of the airplane over the allowable gross weight limit.

Findings · 5

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.

Aircraft capability: maximum weightAircraft › Aircraft oper/perf/capability · Capability exceededCessna 172N: 3 casesAll aircraft: 152 casesProbable cause
Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedCessna 172N: 19 casesAll aircraft: 1,681 casesProbable cause
Personnel issuesPersonnel issues › Action/decision · PilotCessna 172N: 1 caseAll aircraft: 56 casesProbable cause
Wind: gustsEnvironmental issues › Conditions/weather/phenomena · Effect on operationCessna 172N: 28 casesAll aircraft: 1,199 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 commercial pilot was on an on-demand air taxi flight with three passengers and their baggage. He stated that he was approaching a remote airport to land on Runway 15 when the wind shifted and he encountered wind gusts that made the airplane difficult to control. He said that he added full power to go around, but that the airplane would not climb, stalled, and then descended to the ground short of the runway. The airplane sustained substantial damage to the wings and fuselage. Federal Aviation Administration inspectors found no mechanical problems with the airplane and determined that it was being operated at least 166 pounds over the maximum gross weight limit. Operating an airplane over the certificated gross weight is prohibited and markedly reduces its performance capabilities.

Factual narrative

On February 7, 2009, about 0945 Alaska standard time, a Cessna 172N airplane, N5246D, operated by JP Air, Bethel, Alaska, as an on demand, Title 14, CFR Part 135 air taxi flight, crashed during a go-around while on approach to the Atmautluak airport, Atmautluak, Alaska. The commercial pilot and the three passengers reported minor injuries. The flight departed Bethel about 0925, and was en route to Atmautluak, with a return to Bethel. Visual meteorological conditions prevailed, and a company flight plan was in effect. During a telephone interview with the National Transportation Safety Board (NTSB) investigator-in-charge on February 7 at 1515, the pilot reported that he encountered shifting winds during his approach to land on runway 15, and attempted to go-around to land on runway 33. During the attempted go-around, the airplane did not climb as expected, and the pilot said an aerodynamic stall ensued, resulting in a collision with tundra short of the runway. He was asked about the number of passengers and fuel aboard, and said he had full tanks when he departed Bethel, with three passengers and their baggage. In a written report to the NTSB signed by the pilot and director of operations, the fuel quantity at the time of departure from Bethel is listed as 20 gallons and the airplane's gross weight at the time of the accident as 2287 pounds, below the 2300 pounds licensed maximum gross weight. Two Federal Aviation Administration (FAA) aviation safety inspectors traveled to the accident site and to Bethel on February 9 and 10 to inspect the airplane and its records, interview the pilot, and to talk to the witnesses and passengers. In the process, the inspectors discovered that the airplane's licensed empty weight was 1514.6 pounds. Total passenger weights, not accounting for their clothing, was 552 pounds, with an additional 50 pounds of baggage. The pilot's FAA medical weight is listed as 249 pounds, although the FAA inspector who interviewed him is 300 pounds, and thought the pilot was larger than him. Assuming 15 gallons of usable fuel at 6.7 pounds per gallon, the total weight of the airplane at the time of the accident was at least 2466.1 pounds, or 166.1 pounds over the allowable gross weight. Additional fuel, passenger clothing, or pilot's weight in excess of the amount stated, would increase the amount over the maximum allowable gross weight. Copies of the FAA inspector's statements are included in the public docket of this report. In their statements, they note that they pilot indicated he thought the airplane may have been over the allowable gross weight at the time of the accident. The inspectors discovered no evidence of any preimpact mechanical problems with the airplane. In the operator's report to the NTSB, signed by the pilot and director of operations, the block for indicating mechanical malfunction was checked "NO."

Aircraft

Registration
N5246D
Reported as
Cessna 172N
Category
Airplane
Serial number
17272468
Airframe hours
7,614
Engine
Lycoming O-320 SERIES, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Part 135
Operator
JP Air
Registered owner
East Coast Leasing
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · January 6, 2009
Departed
PABE · Bethel, AK
Destination
Atmautluak, AK
Flight plan
Company VFR
Airport
Atmautulak

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.

Weather

Conditions
Visual (VMC) · Day
Wind
310° at 18 knots, gusting 23
Visibility
10 statute miles
Temperature
10 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.