ERA21LA288

NTSB accident investigation · Dehavilland Canada DHC-1 Chipmunk X · Lebanon, TN · July 15, 2021

Accident · Serious injuriesClass 3 · LimitedFinal report
Date
July 15, 2021, 10:00 local (15:00 UTC)
Place
Lebanon, TN · Wooded area adjacent to TN96
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N47YCDehavilland Canada DHC-1 Chipmunk X
Defining event
Initial climb: Loss of engine power (total)
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
20210715022969A
Case key
103485

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 during the initial climb for reasons that could not be determined based on the available evidence.

Findings · 2

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.

AircraftAircraft › Aircraft power plant · Unknown/Not determinedDehavilland Canada DHC-1 CHIPMUNKX: 1 caseAll aircraft: 151 casesProbable cause
Not determinedNot determined › Not determined · Unknown/Not determinedDehavilland Canada DHC-1 CHIPMUNKX: 1 caseAll 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

The pilot reported that, before departure, the right tank was half full, the left tank was full, and that he took off with the fuel selector set to the left tank. The pilot reported that, during the initial climb, the airplane’s engine suddenly lost power. He maneuvered the airplane for a forced landing, and it impacted trees and terrain before coming to a stop. The airplane sustained substantial damage to the fuselage and both wings, and the pilot was seriously injured. An examination of the fuel system and engine did not reveal evidence of a preexisting mechanical malfunction or failure. The cockpit fuel selector handle was found in the right tank position. The right fuel tank was ruptured during the impact sequence and contained no fuel. The left tank, which the pilot reported that he was using at the time of the loss of engine power, held an adequate amount of fuel. Fuel was found in the line from the fuel pumps to the carburetor. The reason for the sudden loss of engine power could not be determined based on the available evidence.

Factual narrative

On July 15, 2021, about 1000 eastern daylight time, a De Havilland Canada DHC-1 Chipmunk X, N47YC, was substantially damaged when it was involved in an accident at Lebanon, Tennessee. The commercial pilot was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he intended to fly the airplane from Fall Creek Field Airport (TN96) in Lebanon, to Lebanon Municipal Airport (M54). After uneventful ground operations, he took off on runway 18 with the fuel selector positioned to the left fuel tank, which was full. He reported that the right fuel tank was half-full. During the initial climb, at an altitude between 100 and 150 ft above the ground, the engine suddenly lost all power; however, it did not seize. The pilot was unable to return to the airport and prepared for a forced landing. He maneuvered the airplane between trees, and the airplane descended into the trees and impacted the ground. The Federal Aviation Administration inspector who responded to the accident site reported that both wings and the fuselage were substantially damaged. The leading edge of the right wing sustained impact damage that penetrated and ruptured the rubberized bladder fuel tank; no fuel remained in the tank. The left-wing fuel tank was undamaged and contained an adequate supply of fuel. The cockpit fuel selector was found in the RIGHT tank position. No contamination or obstructions were found in the fuel system. The De Havilland Gipsy Major engine was examined at an aircraft salvage facility after the accident. The engine remained attached to the airframe. There was impact damage to the propeller, engine mount, firewall, and the lower and left sides of the engine. The engine was turned through by manually rotating the propeller. The engine turned freely through 360° with no binding or unusual noise evident. The two forward cylinders did not show compression or suction when the engine was rotated. Further examination revealed impact damage to the rocker covers and internal components in the cylinder heads. A lighted borescope was then inserted inside both cylinders. The pistons moved up and down normally, and valve action was correct. There were no holes or damage to the pistons or valves. The aft two cylinders were undamaged. When the engine was rotated, compression and suction were observed on both aft cylinders. The dual engine-driven fuel pumps were removed for examination. Fuel was found inside the lines from the fuel pumps to the carburetor. The fuel strainers were opened; both strainers were full of fuel, and the screens were clean and unobstructed. The lever-action pumps functioned normally when operated by hand. The carburetor was examined on the engine. All cockpit controls were connected and exhibited full travel when manipulated by hand. The suction oil filter was removed for examination. The unit contained oil. The screen was removed, and no particulates or contamination wereobserved. The spark plugs were removed for examination. The electrodes were normal in wear and dark in color when compared to a Champion Check-a-Plug chart. The magnetos were removed and tested by rotating with a power drill. Both magnetos produced spark when rotated. The fixed-pitch Fairey Aviation Co. Ltd. two-bladed aluminum propeller remained securely attached to the engine. The propeller spinner was undamaged. The propeller blades exhibited minor impact damage with slight aft bending at the tips. There was no chordwise scratching on the surfaces of the blades or leading-edge damage.

Aircraft

Registration
N47YC
Reported as
Dehavilland Canada DHC-1 Chipmunk X
Category
Airplane
Serial number
147X
Built
1950
Airframe hours
2,179
Engine
DeHavilland Gypsy Major, 145 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Condition · June 17, 2021 · 1 hours before
Destination
M54 · Lebanon, TN
Airport
TN96 · Fall Creek Field, runway 18, 2,700 × 80 ft, grass/turf
Equipment
ADS-B, Auto-pilot, Handheld GPS

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
78
Injuries
Serious
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
BasicMed
Last flight review
July 18, 2020
Seat
Front
Restraint
4-point
Flight hours
9,000 total · 100 in this make and model · 9,000 as pilot in command · 4 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
240° at 4 knots
Visibility
10 statute miles
Temperature
84 °F, dew point 73 °F
Altimeter
30.20 inHg
Observed at
KMQY, 15 nm away
METAR
KMQY 151556Z 24004KT 10SM FEW032 SCT049 29/23 A3020 RMK AO2 SLP228 T02940228

Docket · 5

The files NTSB released with the investigation on June 22, 2023, on NTSB’s docket system: statements, records, photos and specialists’ reports. 17.3 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.