ANC08LA032

NTSB accident investigation · Cessna 207 · Aniak, AK · January 16, 2008

Accident · Serious injuriesLimited investigationFinal report
Date
January 16, 2008, 12:15 local (16:15 UTC)
Place
Aniak, AK
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N1701UCessna 207
Defining event
Enroute-cruise: Loss of engine power (partial)
Weather
Instrument (IMC) · Day
Status
Completed · report August 28, 2008
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA-AL-ANC FSDO 03
FAA report
20080116009939A
Case key
67391

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 NTSB’s determination of the probable cause, and any contributing factors.

A partial loss of engine power for an undetermined reason. Contributing to the accident were the pilot's inadvertent encounter with IMC conditions, and a whiteout during his attempted go-around from an emergency landing approach.

Findings · 5

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings.

Analysis

The commercial certificated pilot was returning from a remote village after a round robin flight of about 130 miles over a frozen and snow-covered river. He was in cruise flight about 500 feet agl, but then circled while holding between 6 or 7 miles east of his destination airport, awaiting a special VFR (SVFR) clearance. The weather condition in that area was about 1 mile visibility, with a ceiling of about 1,000 feet agl. After receiving his SVFR clearance, the pilot flew toward the airport, but the engine fuel pressure began fluctuating. The engine rpm began decreasing, along with the airplane's altitude. The pilot switched fuel tanks, selected full flaps, and prepared for a forced landing. He said the weather was near white-out conditions, but he could see the bank of the river. After switching fuel tanks from the left to the right tank, the engine power suddenly returned to full power. He applied forward flight control pressure to prevent the airplane from climbing too fast, but the airplane collided with the surface of the river. The airplane sustained structural damage to the wings and fuselage. At the time of the accident, the ceiling at the airport was 600 feet obscured, with a visibility of 1/2 mile in snow. Neither the fuel status of the accident airplane, nor the mechanical condition of the engine, were verified by either the NTSB or FAA.

Factual narrative

The factual narrative615 words

On January 16, 2008, about 1215 Alaska Standard time, a Cessna 207 airplane, N1701U, sustained substantial damage when it collided with a snow and ice covered river following a partial loss of engine power, about 1 mile east of Aniak, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country positioning flight under Title 14, CFR Part 91, when the accident occurred. The airplane was operated by Inland Aviation Services Inc., Aniak. The commercial certificated pilot, the sole occupant, received serious injuries. Instrument meteorological conditions prevailed in the area of the accident. VFR company flight following procedures were in effect. The flight originated at the Crooked Creek Airport, Crooked Creek, Alaska, about 1130.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on January 16, the director of maintenance for the operator reported that the pilot received a special VFR (SVFR) clearance into the Aniak Class E airspace about 1153, and was following the Kuskokwim River from Crooked Creek to Aniak. About 1225, the pilot made radio contact with another airplane, and reported that he had crashed.

At the time of the accident, the surface of the Kuskokwim River was frozen and covered by snow.

In a telephone conversation with the NTSB IIC, on January 17, the pilot reported that he initially departed Aniak with full fuel tanks for Crooked Creek, which is about 65 miles from Aniak, along the Kuskokwim river. During the entire flight to and from Crooked Creek, the airplane had been flown between 45 to 60 minutes with the fuel selector on the left tank. The pilot said he was in cruise flight about 500 feet agl, but then circled while holding, about 6 or 7 miles east of Aniak, awaiting a special VFR (SVFR) clearance. The weather condition in that area was about 1 mile visibility, with a ceiling of about 1,000 feet agl. After receiving his SVFR clearance, the pilot proceeded toward Aniak, but the engine fuel pressure began fluctuating, about 3 miles from Aniak. The engine rpm began decreasing, along with his altitude. He switched the fuel selector from the left tank to the right, selected full flaps, and prepared for a forced landing. He said the weather was near white-out conditions, but he could see the bank of the river. After switching fuel tanks, the engine power suddenly returned to full power. He applied forward flight control pressure to prevent the airplane from climbing too fast, but the airplane collided with the surface of the river. The airplane sustained structural damage to the wings and fuselage. The total distance along the Kusokwim River from Aniak, to Crooked Creek and back, was about 130 miles.

At 1156, an automated weather report at Aniak was reporting, in part: Wind, 200 degrees (true) at 6 knots; visibility, 1 statute mile; clouds and sky condition, 600 feet broken, 1,800 feet broken, 12,000 feet overcast; temperature, 32 degrees F; dew point, 30 degrees F; altimeter, 29.77 inHg.

At 1216, the weather at Aniak was reported as: Wind, 190 degrees (true) at 5 knots; visibility, 1/2 statute mile; clouds and sky condition, 600 feet overcast; temperature, 32 degrees F; dew point, 30 degrees F; altimeter, 29.79 inHg.

In the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1) submitted by the director of maintenance for the operator, the ceiling was reported as 600 feet obscured, and the visibility was restricted by snow. No narrative description of the accident events was included in the accident report form.

The fuel status of the airplane at the time of the accident, nor the mechanical condition of the engine, was verified by an NTSB investigator, or a Federal Aviation Administration (FAA) inspector.

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident.

Aircraft

Registration
N1701U
Reported as
Cessna 207
Category
Airplane
Serial number
20700301
Airframe hours
18,448
Engine
Continental IO-520, 300 horsepower, reciprocating
Damage
Substantial damage
Flight
Positioning · Part 91
Operator
Inland Aviation Services Inc.
Registered owner
Inland Holdings Inc.
Airworthiness certificate
Standard, Normal
Last inspection
Annual · October 1, 2007 · 94 hours before
Departed
CJX · Crooked Creek, AK
Destination
PANI · Aniak, AK
Flight plan
Company VFR
Airport
PANI · Aniak

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
Commercial
Airplane ratings
Single-engine land, Single-engine sea
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
March 1, 2007
Seat
Left
Flight hours
9,455 total · 1,914 in this make and model · 40 in the last 90 days · 15 in the last 30 days · 3 in the last 24 hours

Weather

Conditions
Instrument (IMC) · Day
Wind
190° at 5 knots
Visibility
0.5 statute miles
Lowest ceiling
600 ft
Temperature
32 °F, dew point 30 °F
Altimeter
29.79 inHg
Observed at
PANI, 1 nm away

FAA reports on this event · 1

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