CEN21LA133

NTSB accident investigation · Aero Commander S2R · Alamo, TX · February 9, 2021

Accident · No injuriesClass 3 · LimitedFinal report
Date
February 9, 2021, 17:30 local (23:30 UTC)
Place
Alamo, TX
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Prior to flight
Aircraft
N5679XAero Commander S2R
Defining event
Prior to flight: Fuel contamination
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
Flight Standards District Office
FAA report
20210209001149A
Case key
102661

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 partial loss of engine power due to water-contaminated fuel.

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.

Fluids: fuelAircraft › Fluids/misc hardware · Fluid conditionAero Commander S2R: 2 casesAll aircraft: 1,695 casesProbable cause
Object/animal/substance: tree(s)Environmental issues › Physical environment · Contributed to outcomeAero Commander S2R: 1 caseAll aircraft: 933 cases

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 departed for the aerial application flight and noticed an abnormal engine sound as the airplane reached an altitude of about 25 ft above ground level. Concerned that the engine could lose power over obstacles further along the departure leg that included a high traffic highway and a low power line, the pilot elected to make an immediate precautionary landing. During the landing roll, both wings sustained substantial damage due to impact with trees. During postaccident examination of the engine, a small amount of water was observed in the rear carburetor bowl; therefore, it is likely that water-contaminated fuel resulted in a temporary loss of engine power and the abnormal engine sound reported by the pilot. An engine run was conducted with no anomalies noted.

Factual narrative

On February 9, 2021, about 1730 central standard time, an Aero Commander S2R airplane, N5679X, was substantially damaged when it was involved in an accident near Alamo, Texas. The commercial pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. The pilot departed from Mid-Valley Dusters Inc. Airport (43TX) on the last flight of the day and noticed an abnormal sound from the engine as the airplane reached an altitude of about 25 ft above ground level. He elected to make an immediate precautionary landing rather than risk having the engine lose power over obstacles farther along the departure path that included a high traffic highway and a low power line. During the landing roll, both wings sustained substantial damage due to impact with trees. Examination of engine cylinders, spark plugs, induction tubes, exhaust stacks, and magnetos did not reveal any anomalies that would have precluded normal operation. The fuel tank sumps, header tank sumps, and manual auxiliary fuel pump sumps were drained with no contamination noted. The rear carburetor bowl drain was removed, and a small amount of water-contaminated fuel was observed. The engine was started and accelerated to 1,800 rpm with no anomalies noted. A normal rpm drop occurred when the magnetos were checked, and the propeller cycled normally. No smoke was produced when the engine was returned to idle power, which was consistent with normal functioning of the blower seal.

Aircraft

Registration
N5679X
Reported as
Aero Commander S2R
Category
Airplane
Serial number
1879R
Built
1974
Airframe hours
14,028
Engine
Pratt & Whitney R1340 AN-1, 600 hp, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · August 28, 2020
Departed
43TX · Alamo, TX
Airport
43TX · Mid-Valley Dusters Inc Airport, runway 13, 1,900 × 20 ft, macadam

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
77
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine sea, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
February 19, 2020
Seat
Front
Restraint
4-point
Flight hours
19,845 total · 1,200 in this make and model · 19,600 as pilot in command · 60 in the last 90 days · 25 in the last 30 days · 6 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
80° at 11 knots
Visibility
7 statute miles
Lowest ceiling
4,800 ft broken
Temperature
79 °F, dew point 66 °F
Altimeter
30.00 inHg
Observed at
KMFE, 6 nm away

Docket · 4

The files NTSB released with the investigation on May 25, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 8.6 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.