CEN16LA064

NTSB accident investigation · Cessna 305A · Sulphur, LA · November 24, 2015

Accident · Minor injuriesLimited investigationFinal report
Date
November 24, 2015, 14:47 local (19:47 UTC)
Place
Sulphur, LA
Injuries
1 minor, 1 uninjured
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N5312GCessna 305A
Defining event
Approach-VFR pattern crosswind: Fuel contamination
Weather
Visual (VMC) · Day
Status
Completed · report June 25, 2019
Report
Approved by Office Director
NTSB office
Central Region
FAA report
20151124019539A
Case key
92456

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

The loss of engine power due to water and contaminants in the carburetor, which resulted in a forced landing to a wet field.

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.

Engine fuel and control: fuel control/carburetorAircraft › Aircraft power plant · Not specifiedCessna 305A: 1 caseAll aircraft: 195 casesProbable cause
Fluids: fuelAircraft › Fluids/misc hardware · Fluid conditionCessna 305A: 2 casesAll aircraft: 1,695 casesProbable cause
Terrain: wet/muddy terrainEnvironmental issues › Physical environment · Contributed to outcomeCessna 305A: 1 caseAll aircraft: 110 casesProbable cause
Temp/humidity/pressure: conducive to carburetor icingEnvironmental issues › Conditions/weather/phenomena · Not specifiedCessna 305A: 2 casesAll aircraft: 435 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

After about 50 minutes of uneventful flight, the commercial pilot was performing touch-and-go landings. After completing the second touch-and-go landing, the pilot applied full power for takeoff, pushed the carburetor heat control to the forward (off) position, rotated off the runway, and started a standard climb to pattern altitude. While turning on crosswind to set up for a full-stop landing, the engine lost total power. The pilot executed a forced landing in a field with dense, wet vegetation, which resulted in substantial damage to both wings and the fuselage. The pilot-rated passenger reported that the entire flight was normal until the loss of engine power and forced landing. The weather conditions were conducive to the formation of moderate carburetor icing at cruise power or serious icing at descent power. Postaccident examination of the engine revealed that the carburetor was intact and was not impact damaged before disassembly. Further examination found water and corrosion in the carburetor bowl. Although the weather conditions were conducive to the formation of carburetor icing, because of the amount of water and corrosion found in the carburetor, it is likely that the fuel system was contaminated, which caused the loss of engine power.

Factual narrative

On November 24, 2015, about 1447 central daylight time, a Cessna 305 airplane, N5312G, registered to a private individual, sustained substantial damage during a forced landing after a loss of engine power after takeoff from the Southland Field Airport (UXL), Sulphur, Louisiana. The private pilot sustained minor injuries and his pilot-rated passenger was not injured. The flight was being conducted under the provisions of Federal Aviation Regulations Part 91. Visual meteorological conditions prevailed throughout the area and a flight plan was not filed. The flight originated about 1345 from the pilot's private airstrip (52LA), located in Bell City, Louisiana. The pilot, who was also an A&P mechanic, had completed the installation of a CGR-30P engine monitor on November 20, 2015, in N5312G. After the installation, he flew the airplane from 52LA to UXL to check/reset the "K" factor for the fuel flow feature of the monitor. He reported that the flight to and from UXL lasted approximately 30 minutes and the entire flight was uneventful. The pilot reported that the intent of the flight on November 24, 2015, was to deliver the airplane to its owner located at the Lake Charles Regional Airport (LCH), Lake Charles, Louisiana. Prior to departure from 52LA, the pilot decided that he would first fly the airplane to UXL to perform a few touch and go landings and refuel the tanks to recheck the "K'' factor of the new monitor prior to flying to LCH. Upon completion of the second touch and go on runway 15 at UXL, the pilot applied full power for takeoff, pushed the carburetor heat control to the forward/cold position, rotated off the runway, and commenced a standard climb for pattern altitude. At some point at the south end of runway 15, the pilot started a left crosswind turn to set up for a full stop landing on runway 15. At this time, the engine instantaneously stopped firing, and the pilot determined that he would have to make an "off field" landing. The airplane landed ground upright in a field with dense, wet, vegetation. Emergency personnel evacuated the pilot and passenger. Both wings and fuselage sustained substantial damage. The pilot-rated passenger, who was seated in the rear seat, reported that the entire flight was normal until the loss of engine power and forced landing. The nearest weather reporting station (Lake Charles LCH) was located about 20 miles northeast of the accident site. The reported weather observation METAR at LCH about the time of the accident was: KLCH 1435 CDT AUTO 09010KT 10SM SCT4000 19/7 A3019. According to the Icing Probability Chart, with a temperature of 19 degrees and dew point of 7 degrees, the aircraft engine could have been susceptible to moderate carburetor icing at cruise power or serious icing at descent power. The engine was examined on August 8, 2017, at the facilities of Air Salvage of Dallas in Lancaster, Texas. The examination was conducted under the supervision of the FAA. The engine remained attached to theairframe and had no external damage, except for impact damage to the intake air box. The throttle and mixture controls were all connected. The crankshaft was rotated by hand and continuity was confirmed to all cylinders and to the rear of the engine. Good thumb compression was confirmed on cylinders one through five. The cylinders were examined with a lighted boroscope and the number six cylinder had heavy corrosion on the intake valve between the valve and the valve seat, so that the valve could not properly seat. The remainder of the cylinders had dark deposits on the cylinder domes and pistons. The aircraft had been modified with a STC allowing the use of auto gas. The magneto impulse couplings snapped at top dead center on the number one cylinder. The top spark plugs were removed and examined. They had normal wear when compared to the Champion Check-A-Plug comparison card, and dark deposits in the electrode areas. The carburetor was a Marvel Schebler, MA-4-5, PN-10-3859-1, SN-MF-V-AI. The carburetor was found not damaged. Rust and water were observed in the fuel inlet line. The inlet screen was wet with water and corrosion. The unit was disassembled, and the bowl was about half full of water and the bowl was also heavily corroded. The float and needle valve were intact and were free to move.

Aircraft

Registration
N5312G
Reported as
Cessna 305A (A)
Category
Airplane
Serial number
22746
Built
1951
Airframe hours
1,965
Engine
Cont Motor O-470 SERIES, 230 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · September 6, 2015
Departed
52LA · Bell City, LA
Destination
UXL · Sulpher, LA
Airport
UXL · Southland Field Airport, runway 15, 5,001 × 75 ft, asphalt
Equipment
Unknown

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
54
Injuries
Minor
Certificates
Commercial, Private
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Without waivers/limitations
Seat
Front
Restraint
3-point
Flight hours
2,739 total · 3 in this make and model · 15 in the last 90 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
90° at 10 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
66 °F, dew point 45 °F
Altimeter
30.19 inHg
Observed at
LCH

Docket · 5

The files NTSB released with the investigation on April 9, 2019, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.7 MB in all.

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 N5312G · 4

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