Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Birmingham, Alabama
Aviation Accident Final Report - National Transportation Safety Board: https://app.ntsb.gov/pdf
Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms
http://registry.faa.gov/N89904
Location: Cullman, AL
Accident Number: CEN18LA151
Date & Time: 04/25/2018, 1714 CDT
Registration: N89904
Aircraft: CESSNA 152
Aircraft Damage: Substantial
Defining Event: Loss of engine power (total)
Injuries: 1 Minor
Flight Conducted Under: Part 91: General Aviation - Personal
Analysis
After reaching a cruise altitude about 2,500 ft above ground level, the private pilot pulled the engine mixture control toward the lean position too far, and the engine lost total power. The pilot pushed the engine mixture control to the full rich position and attempted unsuccessfully to restart the engine. After one restart attempt, he chose to execute a forced landing, during which the airplane nosed over and sustained damage to the right wing.
Postaccident examination and an engine test run revealed no evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. The pilot did not activate carburetor heat during the flight or after the engine lost power. At the time of the power loss, nearby weather was conducive to the formation of serious carburetor ice at descent power; however, because of the airplane’s altitude and the limited amount of time available, the investigation could not determine whether carburetor icing contributed to his inability to restart the engine. It is likely that the pilot leaned the mixture too much, which resulted in the engine losing total power.
Probable Cause and Findings
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot’s inadvertent engine shutdown due to excessive leaning of the engine and his subsequent inability to restart the engine.
Findings
Personnel issues
Incorrect action performance - Pilot (Cause)
Factual Information
On April 25, 2018, at 1714 central daylight time, a Cessna 152 airplane, N89904, was substantially damaged during a forced landing after departing from Cullman Regional Airport (CMD), Cullman, Alabama. The pilot sustained minor injuries. The airplane was registered to and operated by Guest Aviation LLC under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed for the flight, which departed about 1709 and was destined for Northeast Alabama Regional Airport (GAD), Gadsden, Alabama.
According to the pilot, he departed CMD and climbed to about 2,500 ft above ground level. As he pulled the mixture control toward a lean position for cruise flight, the engine lost power. He pushed the mixture control to a full rich position and attempted unsuccessfully to restart the engine.
The pilot stated that the propeller continued to rotate after the engine lost power. Without an easily accessible engine restart checklist to reference, he relied on memory during the engine restart attempt. The pilot stated he "went through the emergency check, which included the avionics, master switch, fuel selector valve, mixture, and the primer…. although the engine was attempting to restart, it never regained full power".
The pilot did not activate carburetor heat during the flight and thought the throttle lever probably remained at a cruise power setting after the engine lost power. After one restart attempt, he turned his attention to maintaining a proper glide speed and searched for a forced landing area. After identifying a suitable area, he executed a forced landing into a field, during which the airplane nosed over and damaged the right wing.
Examination of the airplane at the accident site revealed the carburetor heat control was in the off position. The engine was started and ran normally at various power settings. No anomalies were noted with the engine or fuel system.
The recorded temperature and dew point data from a nearby weather station were plotted on a carburetor icing chart. The charted data showed that the weather was conducive to moderate icing at cruise power and serious icing at descent power about the time of the engine power loss.
According to the Pilot's Handbook of Aeronautical Knowledge:
When conditions are conducive to carburetor icing during flight, periodic checks should be made to detect its presence. If detected, full carburetor heat should be applied immediately, and it should be left in the ON position until you are certain that all the ice has been removed. If ice is present, applying partial heat or leaving heat on for an insufficient time might aggravate the situation. In extreme cases of carburetor icing, even after the ice has been removed, full carburetor heat should be used to prevent further ice formation. A carburetor temperature gauge, if installed, is very useful in determining when to use carburetor heat.
History of Flight
Enroute-cruise
Loss of engine power (total) (Defining event)
Emergency descent
Off-field or emergency landing
Landing
Hard landing
Nose over/nose down
Pilot Information
Certificate: Private
Age: 20, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used: 3-point
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: No
Medical Certification: Class 3 Without Waivers/Limitations
Last FAA Medical Exam: 09/07/2016
Occupational Pilot: No
Last Flight Review or Equivalent: 03/22/2018
Flight Time: 135 hours (Total, all aircraft), 72 hours (Total, this make and model), 90 hours (Pilot In Command, all aircraft), 36 hours (Last 90 days, all aircraft), 15 hours (Last 30 days, all aircraft), 1 hours (Last 24 hours, all aircraft)
Aircraft and Owner/Operator Information
Aircraft Make: CESSNA
Registration: N89904
Model/Series: 152 NO SERIES
Aircraft Category: Airplane
Year of Manufacture: 1978
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 15282911
Landing Gear Type: Tricycle
Seats: 2
Date/Type of Last Inspection: 11/03/2017, Annual
Certified Max Gross Wt.: 1669 lbs
Time Since Last Inspection: 52 Hours
Engines: 1 Reciprocating
Airframe Total Time: 10878 Hours at time of accident
Engine Manufacturer: LYCOMING
ELT: Installed, activated, aided in locating accident
Engine Model/Series: O-235 SERIES
Registered Owner: GUEST AVIATION LLC
Rated Power: 135 hp
Operator: GUEST AVIATION LLC
Operating Certificate(s) Held: None
Meteorological Information and Flight Plan
Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: K3A1, 963 ft msl
Distance from Accident Site: 13 Nautical Miles
Observation Time: 1715 EDT
Direction from Accident Site: 302°
Lowest Cloud Condition: Clear
Visibility: 10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 6 knots / 15 knots
Turbulence Type Forecast/Actual: None / None
Wind Direction: 330°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 29.98 inches Hg
Temperature/Dew Point: 22°C / 9°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: CULLMAN, AL (CMD)
Type of Flight Plan Filed: VFR
Destination: GADSDEN, AL (GAD)
Type of Clearance: None
Departure Time: 1709 EDT
Type of Airspace: Class E
Wreckage and Impact Information
Crew Injuries: 1 Minor
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 Minor
Latitude, Longitude: 34.152778, -86.634722 (est)
as the pilot said the proppellor was windmilling so attempting a restart does not require the use of the starter because the engine never stops attempting to restart just as it would be if someone were hand propping the engine continuously. the ability of the engine to restart simply depends on where the throttle is positioned. he says the throttle was in the cruise power position which would no doubt choke the engine with way too much fuel. this very thing happened to me recently at low altitude and the engine would not start with even a low power setting. i had to pull the throttle all the way out and the engine started immediately.
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