FTW98LA259

NTSB accident investigation · Ayres S2R · Watson, AR · June 5, 1998

Accident · No injuriesLimited investigationFinal report
Date
June 5, 1998, 07:30 local (12:30 UTC)
Place
Watson, AR
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N4007YAyres S2R
Weather
Visual (VMC) · Day
Status
Completed · report February 15, 2001
Report
Approved by Office Director
FAA report
19980605012609A
Case key
20641

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 the disconnection of the propeller governor control as a result of the stripped threads on the propeller governor control push-pull rod. A factor was the lack of suitable terrain for the forced landing.

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
Propeller governor control,push/pull rod - stripped threadCause
Propeller governor control - disconnectedCause
Forced landingEmergency descent/landing
On ground/water collision with objectLanding - roll
Object - tree(s)
Terrain condition - none suitableFactor

Analysis

While applying herbicide to a rice field, during the pull up at the end of a spray pass, the agricultural airplane's engine lost power. During the ensuing forced landing, the airplane touched down in a field and rolled into a hedgerow of trees. Examination of the engine by a mechanic revealed a discontinuity in the propeller governor control. The threads on the push-pull rod which retain the rod end that bolts to the propeller governor were stripped, and the rod end had separated from the rod. According to the mechanic, the separation of the rod end probably resulted in the reported loss of engine power, since the governor is 'spring loaded' to a high pitch (low rpm) setting. No other discrepancies with the engine were noted, and it was placed on a test stand and ran 'with no problems.'

Factual narrative

On June 5, 1998, at 0730 central daylight time, an Ayres S2R agricultural airplane, N4007Y, registered to and operated by P & D Flying Service of Watson, Arkansas, sustained substantial damage during a forced landing following a partial loss of engine power while maneuvering near Watson. The commercial pilot, the sole occupant, was not injured. No flight plan was filed and visual meteorological conditions prevailed for the Title 14 CFR Part 137 local aerial application flight that departed from a private airstrip 15 minutes before the accident.

According to information provided by the operator to an FAA inspector, the purpose of the flight was to apply herbicide to a rice field. After completion of several spray passes, during the pull up at the end of a pass, the engine lost power. During the ensuing forced landing, the airplane touched down in a field and rolled into a hedgerow of trees. The FAA inspector examined the airplane and reported that the aft section of the fuselage was bowed and twisted, and the right wing incurred structural damage.

The operator removed the engine from the airframe and transported it to Airmotive, Inc., an engine maintenance facility in Clinton, Arkansas. According to an Airmotive mechanic, upon examination of the engine, he found a discontinuity in the propeller governor control. The threads on the push-pull rod which retain the rod end that bolts to the propeller governor were stripped, and the rod end had separated from the rod. According to the mechanic, the separation of the rod end probably resulted in the reported loss of engine power, since the governor is "spring loaded" to a high pitch (low rpm) setting. No other discrepancies with the engine were noted, and it was placed on a test stand and ran "with no problems."

Aircraft

Registration
N4007Y
Reported as
Ayres S2R
Category
Airplane
Serial number
2517R
Airframe hours
3,595
Engine
Pzl-Kalisz PZL-35, 600 horsepower, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
P & D Flying Service, Inc.
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · February 13, 1998 · 166 hours before

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
39
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Center
Flight hours
10,547 total · 4,354 in this make and model · 166 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
210° at 5 knots
Visibility
7 statute miles
Lowest ceiling
25,000 ft broken
Temperature
72 °F, dew point 68 °F
Altimeter
29.00 inHg
Observed at
PBF, 37 nm away

FAA reports on this event · 1

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