ERA24LA082

NTSB accident investigation · Mooney M20K · Tullahoma, TN · January 3, 2024

Accident · No injuriesClass 3 · LimitedFinal report
Date
January 3, 2024, 12:26 local (18:26 UTC)
Place
Tullahoma, TN
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N231GGMooney M20K
Defining event
Enroute: Unknown or undetermined
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
20240103000259A
Case key
193598

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

A total loss of engine power for undetermined reasons.

Findings · 1

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.

Not determinedNot determined › Not determined · Unknown/Not determinedMooney M20K: 4 casesAll aircraft: 2,247 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

Shortly after takeoff, during a cruise climb about 2,000 ft above ground level, the engine suddenly lost all power without any warning. The pilot attempted to glide the airplane back to the departure airport and restart the engine; however, the engine did not restart and the airplane impacted hilly terrain about 1/2-mile before reaching the runway. The engine’s most recent overhaul was about 30 years before the accident, and it accrued about 692 hours during that time. Additionally, the airplane had not been flown for more than 2 years before the accident flight. The pilot did not purchase fuel and the age of the fuel in the airplane could not be determined. During wreckage recovery, about 16 gallons of fuel (8 gallons per side) were drained from the airplane’s fuel tanks. The fuel was blue, clear, and consistent with 100LL aviation gasoline. No visible contamination was observed. Subsequent examination of the engine did not reveal any anomalies, with the exception of an inoperative right magneto; however, that did not explain a total loss of engine power without any engine roughness.

Factual narrative

On January 3, 2024, about 1226 central standard time, a Mooney M20K, N231GG, was substantially damaged when it was involved in an accident near Tullahoma, Tennessee. The commercial pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he had recently purchased the airplane and the accident flight was his first flight in the airplane. The accident flight was also the first flight since the airplane’s most recent annual inspection, which was completed the same day. No anomalies were noted during the preflight inspection, engine start, taxi, and engine run-up. The airplane took off uneventfully from runway 36 at Tullahoma Regional Airport (THA), Tullahoma, Tennessee. The pilot made a right turn southeast for the 20-mile flight back to his home airport, Franklin Country Airport (UOS), Sewanee, Tennessee. The pilot had planned to climb to 4,500 ft mean sea level (msl) for the short flight home. About 3,200 ft msl (2,000 above ground level), the engine suddenly lost all power without any warning. At that time, the airplane was about 4 miles from THA and the pilot turned back to the airport in an attempt to glide to runway 24. He also tried to restart the engine; however, the starter motor would not rotate the propeller. The pilot was unable to glide the airplane to the runway, and it impact hilly terrain about 1/2-mile before reaching the runway. Examination of the wreckage by a Federal Aviation Administration inspector revealed that it came to rest upright. Both wings and the empennage sustained substantial damage. Review of maintenance records revealed that the engine had accumulated about 692 hours since its most recent overhaul in 1994. The engine manufacturer recommended overhaul at 1,500 hours of operation or 12 calendar years, whichever occurs first. Additionally, the airplane had not been flown during the 26-month period before the accident flight. The pilot did not purchase fuel before the accident flight and stated that the fuel onboard could have been 2 years old or older. During recovery, about 16 gallons of fuel (8 gallons per tank) were drained from the airplane’s fuel tanks. The fuel was blue, clear, and consistent with 100LL aviation gasoline. No visible contamination was observed. The engine was examined following recovery of the airplane. The top spark plugs were removed. Their electrodes were intact and light gray in color. The propeller was rotated by hand. Crankshaft, camshaft, and valvetrain continuity were confirmed to the rear accessory section of the engine and thumb compression was attained on all cylinders. The left magneto produced spark at all leads when rotated by hand. The right magneto would not produce spark when rotated by hand. It was disassembled and no anomalies were noted with the points or rotor. The fuel sump and screen were absent of debris.

Aircraft

Registration
N231GG
Reported as
Mooney M20K
Category
Airplane
Serial number
25-0171
Built
1979
Airframe hours
2,406
Engine
Continental TSIO-360-GB-1, 210 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · January 3, 2024 · 0 hours before
Destination
UOS · Sewanee, TN
Airport
THA · Tullahoma Regional Airport, runway 24, 5,501 × 100 ft, concrete
Equipment
Auto-pilot

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
23
Injuries
None
Certificates
Commercial, Flight instructor
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Waiver time limited special
Last flight review
May 25, 2023
Seat
Left
Restraint
3-point
Flight hours
416 total · 0 in this make and model · 392 as pilot in command · 82 in the last 90 days · 23 in the last 30 days · 0 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Lowest ceiling
None
Temperature
39 °F, dew point 30 °F
Altimeter
30.00 inHg
Observed at
THA, 1 nm away
METAR
METAR KTHA 031835Z AUTO 00000KT 10SM CLR 04/M01 A3007

Docket · 4

The files NTSB released with the investigation on January 2, 2025, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.8 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.