SEA98LA140

NTSB accident investigation · Grumman-Schweizer G-164A · Caldwell, ID · July 17, 1998

Accident · No injuriesLimited investigationFinal report
Date
July 16, 1998, 23:00 local (Jul 17, 1998, 05:00 UTC)
Place
Caldwell, ID
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N7951Grumman-Schweizer G-164A
Weather
Visual (VMC) · Night/dark
Status
Completed · report February 11, 2000
Report
Approved by Office Director
FAA report
19980716030799A
Case key
43230

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 pilot-in-command's misjudgment of clearance with a power line, resulting in a collision with the line. Factors included a power line and dark night light conditions in the spray 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.

In flight collision with objectManeuvering - aerial application
Object - wire,transmissionFactor
Clearance - misjudgedPilot in commandCause
Light condition - dark nightFactor

Analysis

The pilot reported that while approaching a field for a spray run, he misjudged the height of a power line in the vicinity of the field and struck the line. The line was cut by the strike. The aircraft, while substantially damaged by the strike, was able to return to its home airstrip and land without further incident. The pilot reported that no mechanical malfunction or failure was involved in the accident. Dark night conditions existed in the accident area at the time.

Factual narrative

On July 16, 1998, approximately 2300 mountain daylight time, a Grumman-Schweizer G-164A agricultural airplane, N7951, operated by Carol's Flying Service of Wilder, Idaho, struck power lines while conducting nighttime agricultural aerial application operations approximately 5 nautical miles south of Caldwell, Idaho. The power lines were cut in the strike. The pilot was able to return to his airstrip near Wilder (from which the flight originated) and land without further incident; he was not injured in the occurrence. Following the occurrence, the airplane was found to have sustained substantial damage. No flight plan was filed for the 14 CFR 137 agricultural aerial application flight.

The pilot reported that while approaching a field for a spray run, he miscalculated wire height and struck the wire. He stated that no mechanical failure or malfunction was involved in the accident.

The pilot's second class FAA medical certificate, dated January 6, 1998, carried a restriction that the pilot must possess glasses that correct for near and intermediate vision. The pilot reported in an August 10, 1998 telephone query that he was wearing his glasses at the time of the accident. The pilot reported that he had 55 hours of night time within the previous 30 days.

Astronomical data computation indicated that at Caldwell, evening twilight on July 16 ended at 2245, and that there was no moon at the time of the accident. The pilot reported the weather as clear with unrestricted visibility.

Aircraft

Registration
N7951
Reported as
Grumman-Schweizer G-164A
Category
Airplane
Serial number
829
Engine
P&W R-985, 450 horsepower, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
Carol'S Flying Service
Airworthiness certificate
Special, Restricted (Special)
Departed
Wilder, ID

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
54
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Center
Flight hours
11,724 total · 7,600 in this make and model · 11,724 as pilot in command · 101 in the last 90 days · 75 in the last 30 days

Weather

Conditions
Visual (VMC) · Night/dark
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
75 °F

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 N7951 · 2

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