DEN08LA085

NTSB accident investigation · North American SNJ-5 · Wolcott, CO · May 5, 2008

Accident · Minor injuriesLimited investigationFinal report
Date
May 5, 2008, 10:35 local (16:35 UTC)
Place
Wolcott, CO
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N12KYNorth American SNJ-5
Defining event
Enroute-cruise: Loss of engine power (total)
Weather
Visual (VMC) · Day
Status
Completed · report July 30, 2008
Report
Approved by Office Director
Parties
FAA Flight Standards District Office
FAA report
20080505833169A
Case key
67948

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 failure of the engine driven fuel pump flange due to oil starvation, resulting in the loss of engine power due to fuel starvation. Contributing to the accident was the lack of suitable terrain for a forced landing.

Findings · 4

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.

Fuel system: fuel pumpsAircraft › Aircraft systems · FailureNorth American SNJ-5: 1 caseAll aircraft: 71 casesProbable cause
Fluids: oilAircraft › Fluids/misc hardware · Fluid levelNorth American SNJ-5: 1 caseAll aircraft: 174 casesProbable cause
Runway/land/takeoff/taxi surfaceEnvironmental issues › Physical environment · Not specifiedNorth American SNJ-5: 1 caseAll aircraft: 253 casesProbable cause
Fluids: fuelAircraft › Fluids/misc hardware · Fluid levelNorth American SNJ-5: 1 caseAll aircraft: 1,695 casesProbable cause

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

According to the pilot, he was in cruise flight at 12,500 feet mean sea level when the engine stopped running. Attempts to restart the engine were unsuccessful. The pilot performed a forced landing to rolling, uneven terrain resulting in substantial damage. Examination of the engine revealed the fuel pump drive gear was pressed into the flange and would not rotate by hand. Several of the gear teeth exhibited damage. The gear shaft exhibited rotational scoring. Half of the engine side lip of the flange was missing. The flange housing was discolored, consistent with heat due to oil starvation. Examination of the engine, fuel pump, remaining engine components, and fuel system revealed no anomalies.

Factual narrative

On May 5, 2008, at 1035 mountain daylight time, a North American SNJ-5, N12KY, piloted by a private pilot, was substantially damaged during a forced landing to a field 8 miles southeast of Wolcott, Colorado. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 without a flight plan. The private pilot sustained minor injuries. The cross-country flight departed Centennial Airport (APA), Englewood, Colorado, approximately 0955 and was en route to Wendover, Nevada.

According to the pilot, he was in cruise flight at 12,500 feet mean sea level when the engine stopped running. He switched fuel tanks, enrichened the fuel mixture, tested the magnetos, and activated the wobble pump, in attempt to restart the engine. These attempts were unsuccessful. The pilot declared an emergency on 121.50 and performed a forced landing to rolling, uneven terrain. During the landing, both wings and the engine separated from the fuselage. The fuselage came to rest inverted in a shallow ravine.

According to the Federal Aviation Administration inspectors who traveled to the scene, the right wing tank was "dry" and the left wing tank was three quarters full. They reported the fuel selector valve was selected for the left tank. The wings were oriented on a slope with the right wing being up slope and the left wing sitting down slope.

The wreckage was recovered and relocated to a hangar in Greeley, Colorado, for further examination. The left wing fuel tank had several holes, was crushed up in several locations, and was wrinkled. The fuel strainer on the left side had bark pressed into it and was not moveable by hand. The right fuel tank was crushed up and wrinkled, and exhibited at least two holes. The fuel strainer was easy to move and manipulate. The wing skin surrounding the fuel strainer had been crushed up around it.

The spark plugs, fuel pump, carburetor, and valve covers were removed. Several cylinders exhibited impact damage. Oil was present throughout the engine. The engine was suspended by the propeller and rotated. Air movement was noted (tactilely) at each spark plug hole. Valve train and engine continuity was noted by the movement of the rocker arms. Impact damage inhibited the movement of the several rocker arms. Movement of the drive at each magneto was noted. Examination of the fuel pump revealed no anomalies.

The drive within the fuel pump flange did not rotate and was not straight. The flange was removed from the engine revealing that the fuel pump drive gear was pressed into the flange and would not rotate by hand. Several of the gear teeth exhibited damage and the gear shaft exhibited rotational scoring. Half of the engine side lip of the flange was missing. The flange housing was discolored and was split along the sides in two locations. Wear and rubbing was noted on the remaining portion of the lip. Galling, and rubbing were noted in the internal portion of the flange housing.

According to the pilot, he had fueled the airplane the evening prior to the flight. The airplane holds 140 gallons of fuel; 70 gallons in each tank. He stated that the engine will consume approximately 35 gallons of fuel per hour. According to the recovery team, they recovered 50 gallons of fuel from the left tank.

Aircraft

Registration
N12KY
Reported as
North American SNJ-5
Category
Airplane
Serial number
90995
Airframe hours
5,229.7
Engine
Pratt & Whitney R 1340 AN1, 600 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · November 1, 2007
Departed
APA · Englewood, CO
Destination
ENV · Wendover, NV

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
48
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Without waivers/limitations
Last flight review
March 1, 2007
Seat
Front
Flight hours
2,731 total · 1,050 in this make and model · 21 in the last 90 days · 6 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
55 °F, dew point 25 °F
Altimeter
30.11 inHg
Observed at
EGE, 15 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 N12KY · 1

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