SEA06LA049

NTSB accident investigation · Cessna 172N · Snohomish, WA · January 31, 2006

Accident · No injuriesLimited investigationFinal report
Date
January 31, 2006, 10:25 local (18:25 UTC)
Place
Snohomish, WA
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N492SFCessna 172N
Weather
Visual (VMC) · Day
Status
Completed · report May 30, 2006
Report
Approved by Office Director
Parties
FAA/FSDO
FAA report
20060131002789A
Case key
63179

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

Carburetor heat was not used during the initial climb in probable serious carburetor icing conditions during cruise power. Carburetor icing conditions and wet terrain were factors.

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 engine powerTakeoff - initial climb
Weather condition - carburetor icing conditionsFactor
Carburetor heat control - not activatedCause
Fuel system,carburetor - ice
Forced landingEmergency landing after takeoff
On ground/water encounter with terrain/waterEmergency landing
Terrain condition - waterFactor
Nose overEmergency landing

Analysis

The pilot reported that shortly after takeoff, the engine lost power after the aircraft attained an altitude of about 250 to 300 feet above ground level. The flight instructor took over the flight controls and accomplished an off airport landing in an open field that was flooded by recent rains. During the landing roll, the airplane nosed over. The wings and a lift strut were damaged, fuel was leaking from the fuel tank(s), and the top of the vertical stabilizer was crushed. After the wreckage was recovered the engine was prepared for an engine run. It was found that the engine started and ran smoothly with no anomalies noted during the run that lasted about 5 minutes in duration. The nearest weather reporting facility located 6 nautical miles to the west was reporting a temperature of 42 degrees F, and dew point of 36 degrees F. The carburetor icing probability chart indicated that for the reported temperature and dew point, the aircraft was operating in probable serious carburetor icing conditions at cruise or climb power.

Factual narrative

On January 31, 2006, about 1025 Pacific standard time, a Cessna 172N, N492SF, registered to and operated by Snohomish Flying Service as a 14 CFR Part 91 local instructional flight, experienced a loss of engine power shortly after takeoff from Harvey Field, Snohomish, Washington. During the off airport landing in a flooded pasture, the airplane nosed over. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft was substantially damaged and the flight instructor and airline transport pilot receiving instruction for an add-on rating/certificate were not injured.

Both pilots reported that shortly after takeoff, the engine lost power after the aircraft attained an altitude of about 250 to 300 feet above ground level. The flight instructor took over the flight controls and accomplished an off airport landing in an open field that was flooded by recent rains. During the landing roll, the airplane nosed over. The wings and a lift strut were damaged, fuel was leaking from the fuel tank(s), and the top of the vertical stabilizer was crushed.

On February 1, 2006, a Federal Aviation Administration Inspector from the Seattle, Washington, Flight Standards District Office, witnessed the start and run-up of the engine after the wreckage had been recovered from the field. The inspector reported that after the fuel system was flushed out, the engine was started, and after a few minutes ran smoothly. The rpm was increased to 1800 and a magneto check was accomplished with no abnormalities noted. The engine was run for about 5 minutes and then shut down. No evidence of a mechanical failure or malfunction was noted during the engine run.

At 0953, the weather facility at Everett, Washington, Paine Field located 6 nautical miles to the west was reporting a temperature of 42 degrees F, and dew point of 36 degrees F. The carburetor icing probability chart indicated that for the reported temperature and dew point, the aircraft was operating in probable serious carburetor icing conditions at cruise or climb power.

Aircraft

Registration
N492SF
Reported as
Cessna 172N
Category
Airplane
Serial number
17268310
Airframe hours
8,729
Engine
Lycoming O-320-H2AD, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Registered owner
Snohomish Flying Service
Airworthiness certificate
Standard, Normal
Last inspection
Annual · November 1, 2005 · 65 hours before
Departed
S43 · Snohomish, WA
Destination
S43
Airport
S43 · Harvey Field

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 · 3

As NTSB recorded them. NTSB leaves out names.

Role
Flight instructor
Age
49
Injuries
None
Certificates
Commercial, Flight instructor
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Helicopter, Airplane
Medical
Class 2
Last flight review
September 1, 2005
Seat
Right
Flight hours
6,239 total · 77 in this make and model · 5,857 as pilot in command · 27 in the last 90 days · 11 in the last 30 days
Role
Student pilot
Injuries
None
Role
Pilot
Age
45
Injuries
None
Certificates
Flight instructor, Airline transport, Commercial
Airplane ratings
Multi-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 1
Last flight review
September 1, 2005
Seat
Left
Flight hours
8,506 total · 5 in this make and model · 4,200 as pilot in command · 52 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
150° at 12 knots
Visibility
10 statute miles
Lowest ceiling
4,700 ft broken
Temperature
43 °F, dew point 36 °F
Altimeter
29.89 inHg
Observed at
PAE, 6 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.

Other investigations on N492SF · 1

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