Grumman G164-A N72ES

Summary

On 28 February 2014 at about 17:55 local time, a Grumman G164-A registered N72ES, operated by Trinkle Ag Flying, was involved in an accident near Caruthers, California, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

28 February 2014 at 17:55

Classification

Accident

Location

Caruthers, California, United States

Nearest airport

Kenny's Cropdusting (None)

Coordinates

36.5419, -119.7642

Aircraft

Grumman G164-A

Registration

N72ES

Category

Airplane

Year built

1972

Engines

1

Operator

Trinkle Ag Flying

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Caruthers → Caruthers

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR14LA130

Nobody was injured.

An undetected fatigue crack in the landing gear leg, which initiated at an electrical arc-induced damage site of undetermined origin and resulted in landing gear failure. Contributing to the severity of damage to the airplane was the close proximity of an embankment to the runway.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot completed his third aerial application sortie of the day in the airplane, and was returning for landing on the paved private airstrip. On touchdown, the pilot heard a "huge bang," and the airplane began to roll right wing down. The pilot tried to correct with aileron, but as the airplane slowed, its right wing contacted the ground. The airplane veered to the right, departed the paved surface, and struck an embankment that bordered the runway, which caused the airplane to nose over. The airplane came to rest inverted, partially down the embankment. Examination of the airplane revealed that the right main landing gear leg had fractured and separated near the upper bend just below the fuselage. Laboratory analysis revealed that the leg failure was the result of a fatigue crack that went undetected until the remaining material was insufficiently strong to sustain the landing load. The fatigue crack originated at the site of electrical arc damage to the gear leg. Possible mechanisms for the arc damage included a power line strike, a lightning strike, improper grounding during weld repairs to the airframe, or processing damage during overhaul of the landing gear. Because the gear leg was heat-treated, the airplane manufacturer prohibited welding of the leg. The presence and condition of paint on the gear leg's surface at the site of the arc damage indicated that the damage occurred before the paint was applied and that the gear leg had not been painted in the recent past. Finding paint covering the damage raises questions about what inspections were performed on the gear leg and the efficacy of the inspections; however, because the maintenance records were not available, the history of the gear leg could not be determined.

Quoted verbatim from the NTSB record.