FTW97LA322

NTSB accident investigation · Rockwell S-2R · Columbus, NM · August 21, 1997

Accident · Serious injuriesLimited investigationFinal report
Date
August 21, 1997, 14:35 local (20:35 UTC)
Place
Columbus, NM
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N4893XRockwell S-2R
Weather
Visual (VMC) · Day
Status
Completed · report November 10, 1998
Report
Approved by Office Director
FAA report
19970821030539A
Case key
20323

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

a loss of engine power due to failure of an exhaust side rocker box and valve mechanism, and pilot incapacitation due to loss of consciousness after being struck in the head by parts separating from the engine.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(partial) - mech failure/malfManeuvering - aerial application
Engine assembly,rocker arm/tappet - separationCause
Engine assembly,valve,exhaust - separationCause
Loss of control - in flightManeuvering - aerial application
Aircraft control - uncontrolledPilot in commandCause
Incapacitation(loss of consciousness)Pilot in commandCause
In flight collision with terrain/waterDescent - uncontrolled

Analysis

The airplane impacted terrain following a loss of engine power while maneuvering. The pilot stated 'on the final pass [he] pulled up out of the field and initiated a turn towards Deming, when an object came through the right corner windshield striking [him] in the head,' rendering him unconscious. A witness who was approximately 1 mile from the accident site stated that he saw the airplane 'flying straight and then nose into the ground.' The witness did not hear any engine noises. Several workers, in a nearby field, reported that they observed the airplane pull out of the field and start to turn, when the engine quit. The owner examined the engine and determined that the exhaust side rocker box and exhaust valve mechanism had broken off the number 7 cylinder. There was a 'deep groove' on the back side of a propeller blade. The owner stated that the rocker box could have been ejected from the engine and contacted a propeller blade which deflected the rocker box into the cabin.

Factual narrative

On August 21, 1997, at 1435 mountain daylight time, a Rockwell S-2R agricultural airplane, N4893X, owned and operated by Farm and Ranch Aviation Company, Deming, New Mexico, was substantially damaged when it impacted terrain following a loss of engine power, while maneuvering near Columbus, New Mexico. The commercial pilot, sole occupant, received serious injuries. Visual meteorological conditions prevailed for the Title 14 CFR Part 137 aerial application flight. The flight originated from a farm strip in Certzalia, New Mexico, at 1420, and no flight plan was filed.

The pilot reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that he had just completed an aerial application order for a farm located 12 miles west Columbus, New Mexico, when the accident occurred.

The pilot stated the following; "on the final pass [he] pulled up out of the field and initiated a turn towards Deming, when an object came through the right corner windshield striking [him] in the head." The pilot was rendered unconscious. He regained consciousness as the left wing contacted the ground, and the airplane cartwheeled coming to rest upright in brush covered, desert like terrain.

A witness who was approximately 1 mile from the accident site stated that, he saw the airplane "flying straight and then nose into the ground." He added that, he did not hear any engine noises. Several witnesses in a nearby field, reported to the pilot that when he started to pull the airplane out of the field and turn, the engine quit.

Examination of the aircraft wreckage by an FAA representative revealed that the wreckage was distributed along a path 75 yards in length. The engine and engine mounts were separated from the airframe. The propeller blades were bent in a "horse shoe" shape. The left wing was twisted, torn and bent upwards. A portion of the left wing was located 20 yards from the main wreckage. The right wing separated from the airplane and remained intact. The right main landing gear and tail wheel separated from the airplane. Control cable continuity was established to the ailerons and elevator.

The engine was examined by the owner. The owner reported that it "appears" that the exhaust side rocker box and exhaust valve mechanism broke away from the number 7 cylinder. There was a "deep groove" on the back side of a propeller blade. The owner stated that the rocker box could have been ejected from the engine and contacted a propeller blade, which deflected the rocker box into the cabin.

No further examination of the aircraft was conducted.

Aircraft

Registration
N4893X
Reported as
Rockwell S-2R
Category
Airplane
Serial number
2078R
Engine
P&W R-1340-AN1, 600 horsepower, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
Robert J. Mamuzich
Registered owner
Farm And Ranch Aviation Co.
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · March 1, 1997 · 80 hours before
Departed
DMN · Deming, NM

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
63
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Center
Flight hours
17,000 total · 10,000 in this make and model · 17,000 as pilot in command · 300 in the last 90 days · 100 in the last 30 days · 6 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
200° at 5 knots, gusting 10
Visibility
20 statute miles
Lowest ceiling
None
Temperature
97 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.