CEN20LA055

NTSB accident investigation · Aero Commander 100 · Mullin, TX · January 4, 2020

Accident · No injuriesClass 3 · LimitedFinal report
Date
January 4, 2020, 16:00 local (22:00 UTC)
Place
Mullin, TX
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N5573MAero Commander 100
Defining event
Approach: Loss of engine power (total)
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
FAA San Antonio FSDO
FAA report
20200104000859A
Case key
100769

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 reasons that could not be determined based on the available information.

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.

Engine (reciprocating)Aircraft › Aircraft power plant · Unknown/Not determinedAero Commander 100: 1 caseAll aircraft: 497 casesProbable cause
Not determinedNot determined › Not determined · Unknown/Not determinedAero Commander 100: 3 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

The flight instructor and student pilot were conducting a cross-country flight. During a gradual descent to the destination airstrip, the engine lost total power, and the airplane sustained substantial damage during the subsequent forced landing. The airplane was recovered from the accident site and an engine examination and test run revealed no anomalies. Examination of the fuel selector revealed that either the fuel selector handle or the pointer was installed 180° out of position. When the selector handle was selected to BOTH, the valve was completely closed, in what should have been the OFF position. When the selector handle was selected to OFF, the valve was open, in what should have been the BOTH position. The temperature and dewpoint for the accident time and accident site were not conducive to the formation of carburetor icing. It is possible that if the fuel selector was manipulated to the BOTH position during the flight, the fuel may have been prevented from reaching the engine due to the incorrect installation of the selector handle. However, the examination could not determine whether it was the selector handle or the pointer that was installed incorrectly. Based on the available evidence, the reason for the total loss of engine power could not be determined.

Factual narrative

On January 4, 2020, about 1600 central standard time, an Aero Commander 100 airplane, N5573M, sustained substantial damage when it was involved in an accident near Mullin, Texas. The student pilot and flight instructor were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor reported that he and the student departed on the 75-nautical-mile flight with 40 gallons of fuel onboard. About 3 miles from the destination airstrip, they initiated a slow descent to a private airstrip. The student completed the Descent and the Before Landing checklist. About 3,000 ft above mean sea level, the engine lost total power. The instructor immediately took control of the airplane and ensured that the fuel selector switch was selected for both fuel tanks, the carburetor heat was applied, and the mixture control was at the full-rich position. He trimmed the airplane for its best glide speed and the student completed a mayday call. The instructor switched fuel tanks; however, the engine did not respond, and the propeller was “wind milling.” The instructor performed a forced landing to a flat, plowed dirt field, during which the right wingtip impacted a tree and the airplane nosed over. The airplane sustained substantial damage to the fuselage, both wings, and the empennage. The fuel system was breached during the accident and the exact amount of fuel onboard at the time of the loss of engine power could not be determined. The airplane was recovered from the accident site and an engine run was performed. The engine successfully ran for several minutes at various power settings when a fuel source was plumbed to the engine. No mechanical anomalies were found during the engine run. Examination of the fuel selector revealed that either the fuel selector handle or the pointer was installed 180° out of position. When the selector handle was selected to BOTH, the valve was completely closed, in what should have been the OFF position. When the selector handle was selected to OFF, the valve was open, in what should have been the BOTH position. The hole on the end of the pointer that slid over the shaft featured a round side and a flat side, which helps to correctly orient the pointer during installation. The hole was sufficiently worn that the pointer would fit over the shaft in both directions. The examination could not determine if the selector handle or the pointer was installed incorrectly. The temperature and dewpoint for the accident time and accident site were not conducive to the formation of carburetor icing.

Aircraft

Registration
N5573M
Reported as
Aero Commander 100 (UNDESIGNAT)
Category
Airplane
Serial number
107
Built
1967
Airframe hours
2,335.38
Engine
Lycoming Engines O-320-A2B, 150 horsepower, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · June 28, 2019
Departed
ABI · Abilene, TX
Destination
Mullin, TX
Airport
Private Airstrip
Equipment
Stall warning system, 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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Flight instructor
Age
33
Injuries
None
Certificates
Commercial, Flight instructor
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
April 22, 2019
Seat
Right
Restraint
Lap only
Flight hours
1,756 total · 10 in this make and model · 1,659 as pilot in command · 25 in the last 90 days · 10 in the last 30 days
Role
Student pilot
Age
42
Injuries
None
Certificate
Student
Medical
Class 3, With waivers/limitations
Seat
Left
Restraint
Lap only
Flight hours
77.1 total · 57.9 in this make and model · 70.5 as pilot in command · 39.5 in the last 90 days · 18.7 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
260° at 3 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
68 °F, dew point 30 °F
Altimeter
30.28 inHg
Observed at
KMKN, 16 nm away

Docket · 6

The files NTSB released with the investigation on September 23, 2021, on NTSB’s docket system: statements, records, photos and specialists’ reports. 23.1 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.