ANC05LA133

NTSB accident investigation · Cessna 206 · Yakutat, AK · September 2, 2005

Accident · No injuriesLimited investigationFinal report
Date
September 1, 2005, 17:00 local (Sep 2, 2005, 01:00 UTC)
Place
Yakutat, AK
Injuries
5 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N4991FCessna 206
Weather
Visual (VMC) · Day
Status
Completed · report June 28, 2006
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA-AL JNU FSDO 05
FAA report
20050901024419A
Case key
62400

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 selection of unsuitable terrain for takeoff, and his failure to maintain adequate airspeed during takeoff initial climb from a remote airstrip, which resulted in the airplane descending to the ground and colliding with soft terrain beyond the end of the airstrip. Factors contributing to the accident were the rough/uneven airstrip surface consisting of humps and rocks, and an inadvertent stall/mush.

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.

Loss of control - in flightTakeoff - initial climb
Unsuitable terrain or takeoff/landing/taxi area - selectedPilot in commandCause
Terrain condition - rough/unevenFactor
Airspeed(vs) - not maintainedPilot in commandCause
Stall/mush - inadvertentPilot in command
Climb - not attainedPilot in command
In flight collision with terrain/waterDescent - uncontrolled
Terrain condition - soft
Terrain condition - water

Analysis

The airline transport certificated pilot, with four passengers, fishing equipment, and a dog aboard, were departing on a personal flight from a remote gravel airstrip that was 1,100 feet long and 10 feet wide. The FAA's Airport/Facility Directory, Alaska Supplement listing for the airstrip includes "...dips and humps 8 to 12 inches entire length. Rocks on surface to 3 inches. Runway used as a road." The pilot told the NTSB investigator-in-charge (IIC) that during the takeoff roll, the airplane became airborne in ground effect, but the engine power rapidly decreased, and the airplane settled into about 12 inches of water in a tidal zone. The pilot indicated that the airplane had flown through heavy rain in the previous four days, but he had not encountered any problems until the accident takeoff. The airplane received structural damage to the right wingtip and right wing root. An FAA inspector interviewed the pilot and passengers, and reported that the pilot told him the airplane became airborne after hitting some bumps about 2/3 of the way down the runway. The pilot said he attempted to keep the airplane airborne in ground effect, but it settled to the soft ground beyond the end of the runway in high grass and water. Based on his interviews, the inspector estimated that the airplane was within 100 pounds of its gross weight limit. The inspector indicated that air taxi operators in the local area only use the airstrip while carrying a reduced load due to the condition of the airstrip surface. Sufficient structural and propeller repairs were made to the airplane at the accident scene allowing it to be flown out by recovery personnel, and they did not report any engine problems.

Factual narrative

On September 1, 2005, about 1700 Alaska daylight time, a wheel-equipped Cessna 206 airplane, N4991F, sustained substantial damage when it collided with soft terrain in a tidal area during takeoff initial climb from a remote airstrip, about 45 miles east of Yakutat, Alaska. The airplane was being operated by the pilot as a visual flight rules (VFR) local area personal flight under Title 14, CFR Part 91, when the accident occurred. The airline transport certificated pilot and the four passengers were not injured. Visual meteorological conditions prevailed. The flight originated at the East Alsek River airstrip, and was en route to the Tanis Mesa airstrip. No flight plan was filed.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on September 2, the pilot reported that he was departing on runway 20 from the gravel surfaced East Alsek River airstrip, which is 1,100 feet long, and 10 feet wide. The pilot said that during the takeoff roll, the airplane became airborne in ground effect, but the engine power rapidly decreased, and the airplane settled into about 12 inches of water in the tidal zone of the East Alsek River. During the touchdown, the right main landing gear dug into the soft sand, spinning the airplane to the right. The propeller and right wingtip struck the ground. The pilot indicated that the airplane had flown through heavy rain in the previous four days, but he had not encountered any problems until the accident takeoff. The airplane received structural damage to the right wingtip and right wing root.

The FAA's Airport/Facility Directory, Alaska Supplement listing for the airstrip states, in part: "Unattended. Runway 02-20 [has] dips and humps 8 to 12 inches entire length. Rocks on surface to 3 inches. Runway used as a road."

On September 12, recovery personnel reported via telephone that sufficient airframe and propeller repairs were made to the airplane at the accident site, and it was flown to Anchorage, Alaska. On January 11, 2006, recovery personnel stated that no engine problems were encountered during the recovery process.

The pilot was sent a Pilot/Operator Aircraft Accident Report (NTSB form 6120.1) on September 7, but the form was not received at the NTSB's Alaska Regional Office, Anchorage. During a telephone conversation with the NTSB IIC on December 13, the pilot reported that he mailed the form. A second NTSB Form 6120.1 was sent to the pilot on December 13, but was not received at the NTSB's Alaska Regional Office.

An FAA Air Safety Inspector, Juneau Flight Standards District Office, Juneau, Alaska, interviewed the pilot and passengers. The inspector reported that the pilot told him the airplane became airborne after hitting some bumps about 2/3 of the way down the runway. The pilot said he attempted to keep the airplane airborne in ground effect, but it settled to the ground beyond the end of the runway in high grass and water. Based on his interviews, the inspector estimated that the airplane was within 100 pounds of its gross weight limit with the pilot and passengers, fishing equipment, and a dog aboard. The airplane was not equipped with oversize tires. The inspector indicated that air taxi operators in the local area only use the airstrip while carrying a reduced amount of load due to the condition of the airstrip surface.

Aircraft

Registration
N4991F
Reported as
Cessna 206
Category
Airplane
Serial number
U2060691
Engine
Continental IO-520, 300 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
Christopher P. Chouinard
Airworthiness certificate
Standard, Normal
Last inspection
Annual · December 1, 2004
Departed
AK76 · Yakutat, AK
Destination
A69 · Yakutat, AK
Airport
AK76 · East Alsek River, runway 20, 1,100 × 10 ft, gravel

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
50
Injuries
None
Certificates
Private, Airline transport, Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Seat
Left
Flight hours
11,600 total

Weather

Conditions
Visual (VMC) · Day
Visibility
10 statute miles
Lowest ceiling
None
Temperature
64 °F

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 N4991F · 2

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