ATL95LA172

NTSB accident investigation · Grumman G-164A · Lynchburg, SC · September 22, 1995

Accident · No injuriesLimited investigationFinal report
Date
September 22, 1995, 10:30 local (14:30 UTC)
Place
Lynchburg, SC
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N9700Grumman G-164A
Weather
Visual (VMC) · Day
Status
Completed · report April 29, 1996
Report
Approved by Office Director
FAA report
19950922030119A
Case key
3628

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 failure of the magneto mount pad, which resulted in a malfunction of the magneto timing and partial loss of engine power. A factor relating to the accident was: high vegetation in the emergency landing area.

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/malfCruise
Ignition system,magneto - failureCause
Forced landingEmergency descent/landing
Nose overEmergency landing
Terrain condition - cropFactor

Analysis

During cruise flight, while the pilot was returning from spraying a field, the engine began running roughly. The pilot stated he checked both magnetos, and then the engine lost power. He attempted to restart the engine, but was unable to do so. He elected to land in a soybean field. During the flare, the landing gear was caught by the 5 foot high soybean crop, and the aircraft nosed over. Postcrash examination showed that the right magneto timing had been lost, because the rear attachment base had broken, permitting the magneto to shift.

Factual narrative

On September 22, 1995, about 1030 eastern daylight time, a Grumman G164A, N9700, nosed over during a forced landing near Lynchburg, South Carolina. The airplane was operated by Sky Ag Aviation, under the provisions of 14 CFR Part 91, and visual flight rules. Visual meteorological conditions prevailed. A flight plan was not filed for the ferry flight. There were no injuries to the commercial pilot, and the airplane was substantially damaged. Origination of the flight was at approximately 1000, from Lynchburg, South Carolina.

The pilot stated that during the ferry flight from spraying a field, the engine began running roughly. He checked the magnetos with no improvement in the roughness. The pilot then added power, and the roughness increased, resulting in a forced landing in a soybean field. During the landing roll the airplane nosed over.

Post accident investigation displayed that the engine would not start with the magnetos turned to the both position. With the magneto switch placed in the left position, the engine started and ran steadily. Further investigation disclosed that the left rear attachment bolt for the right magneto was missing, and the safety wire was broken. The right rear corner of the magneto was broken, allowing the magneto to shift enough to jump the teeth of the magneto to the engine drive coupling. This resulted in a loss of engine to magneto timing. The fracture faces of the broken magneto mount were dirty and fretted, except for one small area: indicative of a pre-existing fracture.

Aircraft

Registration
N9700
Reported as
Grumman G-164A
Category
Airplane
Serial number
1232
Airframe hours
3,770
Engine
P&W R-985, 450 horsepower, reciprocating
Damage
Substantial damage
Flight
Positioning · Part 91
Registered owner
Sky Ag Aviation
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · December 1, 1994 · 488 hours before
Departed
PVT · Tallon Field, SC

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
48
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Front
Flight hours
10,000 total · 2,000 in this make and model · 10,000 as pilot in command · 100 in the last 90 days · 50 in the last 30 days · 6 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
160° at 6 knots
Visibility
3 statute miles
Lowest ceiling
700 ft broken
Temperature
75 °F, dew point 75 °F
Altimeter
30.00 inHg
Observed at
SSC, 15 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.

Other investigations on N9700 · 1

Matched to the same aircraft by N-number and date.