ERA24LA087

NTSB accident investigation · Cessna 150 · Hohenwald, TN · January 10, 2024

Accident · No injuriesClass 3 · LimitedFinal report
Date
January 10, 2024, 08:15 local (14:15 UTC)
Place
Hohenwald, TN
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N7UTCessna 150
Defining event
Enroute: Fuel related
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO
FAA report
20240110000489A
Case key
193639

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 failure to use carburetor heat in conditions conducive to the formation of carburetor ice, which resulted in a partial loss of engine power due to fuel starvation. Contributing to the outcome was her failure to attain a proper touchdown point during the subsequent diversionary landing, which resulted in a runway excursion.

Findings · 3

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.

Use of equip/info: use of equip/systemPersonnel issues › Task performance · PilotCessna 150M: 3 casesAll aircraft: 1,391 casesProbable cause
Temp/humidity/pressure: conducive to carburetor icingEnvironmental issues › Conditions/weather/phenomena · Effect on equipmentCessna 150M: 9 casesAll aircraft: 435 casesProbable cause
Performance/control parameters: descent/approach/glide pathAircraft › Aircraft oper/perf/capability · Not attained/maintainedCessna 150M: 1 caseAll aircraft: 809 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

The student pilot was on a solo cross-country flight when the accident occurred. She noticed no irregularities during the preflight inspection, engine run-up, or climb out. About 80 nautical miles (nm) into the flight, while operating at 2,500 ft mean sea level, the engine began to run rough. The pilot moved the throttle and mixture to full, but the engine continued to progressively operate rougher with a subsequent decrease in engine rpm. Unable to maintain altitude, the pilot diverted to the nearest airport. While on final approach, the airplane was high and fast, and she did not believe there was enough altitude to complete a 180° turn to bleed off airspeed, so she continued the approach. The airplane landed long down the runway, exited the paved surface, and collided with a fence resulting in substantial damage to the wings and elevator. Postaccident examination and a test run of the engine did not reveal evidence of any preexisting anomalies or failures that would have prevented normal operation. The recorded temperature and dew point near the accident site were conducive to “serious icing” at cruise engine power settings. The pilot described the troubleshooting tasks she performed while trying to diagnose the reason for the loss of engine power, but did not report using carburetor heat. Based on this information, carburetor ice likely formed during the cruise portion of the flight, which resulted in a partial loss of engine power and a forced landing. During the approach, the pilot was high, fast, and landed long resulting in a runway excursion.

Factual narrative

On January 10, 2024, about 0815 central standard time, a Cessna 150M, N7UT, was substantially damaged when it was involved near Hohenwald, Tennessee. The student pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The student pilot reported that she was conducting a solo cross-country flight. The first leg was planned from Tullahoma Regional Airport/William Northern Field (THA), Tullahoma, Tennessee, to Hassell Field Airport (M29), Clifton, Tennessee, which was about 90 nm. Shortly after receiving a weather briefing and flight instructor signoff for the solo flight, the student pilot ensured the fuel was topped off. The preflight inspection and engine run-up were normal with no irregularities found. The subsequent takeoff and climb to the cruising altitude were normal. About 80 nm into the flight, while cruising at 2,500 ft mean sea level and 2,400 rpm, the engine began to run rough. The pilot moved the throttle to full, confirmed that the mixture was full rich, and checked the fuel selector valve. The pilot did not report using carburetor heat at any point during her troubleshooting efforts. The engine continued to progressively operate rougher with a subsequent decrease in rpm and the pilot was unable to maintain altitude. The pilot elected to divert to Paul Bridges Field Airport (0M3), Hohenwald, Tennessee. While on final approach, the airplane was high and fast; however, the pilot did not believe the airplane was high enough to bleed off airspeed and make a 180° turn to lose altitude, so she continued the approach and landed long down the runway. Unable to stop the on the remaining runway using full brakes, the airplane exited the paved surface of the runway and struck a fence resulting in substantial damage to the wings and elevator. A visual inspection of the engine was conducted at the accident scene, and a visual inspection of fuel samples from the engine and wing drains found no sign of water or obstructions. A postaccident engine run was conducted and revealed no anomalies that would have prevented normal operation. According to the FAA carburetor icing chart, the temperature, 2°C, and dew point, -2°C, recorded at the weather reporting station closest to the accident site, were conducive to “serious icing” at cruise power settings.

Aircraft

Registration
N7UT
Reported as
Cessna 150 (M)
Category
Airplane
Serial number
15076100
Built
1974
Airframe hours
6,037
Engine
Continental O-200-A, 100 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Operator
Volunteer Aviation Foundation Inc
Registered owner
Volunteer Aviation Foundation Inc
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · November 12, 2023 · 81 hours before
Departed
THA · Tullahoma, TN
Destination
Same as departure
Flight plan
VFR
Airport
0M3 · Paul Bridges Fld, runway 02/20, 4,001 × 75 ft, asphalt
Equipment
ADS-B, Stall warning system

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
26
Injuries
None
Certificate
Student
Medical
Class 3, Without waivers/limitations
Seat
Left
Restraint
4-point
Flight hours
50 total · 39 in this make and model · 8.1 as pilot in command · 47.7 in the last 90 days · 31.2 in the last 30 days · 1.4 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
250° at 7 knots
Lowest ceiling
2,300 ft overcast
Temperature
36 °F, dew point 28 °F
Altimeter
29.84 inHg
Observed at
LUG, 32 nm away
METAR
METAR KLUG 101355Z AUTO 24010KT 10SM OVC024 02/M02 A2984 RMK A01=

Docket · 6

The files NTSB released with the investigation on March 19, 2025, on NTSB’s docket system: statements, records, photos and specialists’ reports. 10.2 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.