WPR21LA200

NTSB accident investigation · Grumman Acft ENG Cor-Schweizer G-164C · Glenn, CA · May 12, 2021

Accident · Serious injuriesClass 3 · LimitedFinal report
Date
May 12, 2021, 10:30 local (17:30 UTC)
Place
Glenn, CA · rice field
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N6596KGrumman Acft ENG Cor-Schweizer G-164C
Defining event
Initial climb: Fuel exhaustion
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration
FAA report
20210512021199A
Case key
103110

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

The pilot’s fuel mismanagement, which resulted in fuel exhaustion, a total loss of engine power, and an off-airport hard landing.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Fluids: fuelAircraft › Fluids/misc hardware · Fluid managementGrumman Acft ENG Cor-Schweizer G-164C: 2 casesAll aircraft: 1,695 casesProbable cause
Fluids: fuelAircraft › Fluids/misc hardware · Fluid levelGrumman Acft ENG Cor-Schweizer G-164C: 2 casesAll aircraft: 1,695 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The pilot reported that, he departed for the aerial application flight with the fuel gauge indicating a half-full tank of fuel and a full load of product. About 100 ft above ground level the engine lost total power. The pilot elected to make a forced landing to a narrow dirt frontage road. The airplane landed hard and came to rest upright. The wings and fuselage were substantially damaged. Postaccident examination of the airframe revealed that no usable fuel was present in the center fuel tank nor from the wing fuel tanks. Maintenance personnel reported that they checked the fuel gauge in the cockpit, and it revealed that the center fuel tank was indicating half full. When the float connected to an arm in the center tank was manipulated, the fuel gauge in the cockpit moved but not in a manner coincident with the placement of the float, and that the fuel gauge may have been reporting false quantities of fuel. An engine inspection revealed no preaccident mechanical failures or malfunctions that would have precluded normal operation. The pilot reported that he did not refuel the airplane based on the fuel gauge indications that the fuel tank was half full. Thus, the pilot did not properly manage the airplane’s fuel, which resulted in fuel exhaustion and the total loss of engine power.

Factual narrative

On May 12, 2021, about 1030 Pacific daylight time, a Grumman ACFT ENG COR Schweizer G-164C, N6596K, was substantially damaged when it was involved in an accident near Glenn, California. The pilot was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 agricultural flight. The pilot reported that the airplane had just departed with the fuel gauge indicating a half-full tank of fuel and a full load of product (2,200 pounds of rice seed). About 100 ft above ground level the engine lost total power. He saw a narrow dirt frontage road in between rice fields and made a forced landing, during which the airplane landed hard and came to rest upright, causing substantial damage to the wings and fuselage. The pilot reported that he did not refuel the airplane before the accident flight based on the fuel gauge indications. The operator reported that the center fuel tank, which draws fuel from the two wing tanks was empty of fuel. About 1 gallon of fuel was recovered from the fuel sump. The engine and the fuel systems remained intact and uncompromised. Maintenance personnel reported that they checked the fuel gauge in the cockpit, and it revealed that the center fuel tank was indicating half full. When the float connected to an arm in the center tank was manipulated, the fuel gauge in the cockpit moved but not in a manner coincident with the placement of the float, and that the fuel gauge may have been reporting false quantities of fuel. The engine was sent to a repair facility for overhaul with no discrepancies identified. Further testing of the fuel gauge was not accomplished.

Aircraft

Registration
N6596K
Reported as
Grumman Acft ENG Cor-Schweizer G-164C
Category
Airplane
Serial number
6C
Built
1978
Airframe hours
22,400
Engine
Pratt & Whitney PT-6-41, turbo prop
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
Jones Aviation Inc.
Registered owner
Jones Aviation Inc.
Airworthiness certificate
Standard, Utility
Destination
Same as departure
Flight plan
Company VFR
Airport
N/A
Equipment
Unknown

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
45
Injuries
Serious
Certificate
Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
November 16, 2020
Seat
Center
Flight hours
1,550 total · 350 in this make and model · 100 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
130° at 4 knots
Visibility
10 statute miles
Temperature
82 °F, dew point 43 °F
Altimeter
29.98 inHg
Observed at
KOVE, 21 nm away
METAR
KOVE 121753Z AUTO 13004KT 10SM CLR 28/06 A2998 RMK AO2 SLP151 T02830056 10283 20150 53009

Docket · 5

The files NTSB released with the investigation on June 8, 2023, on NTSB’s docket system: statements, records, photos and specialists’ reports. 10.5 MB in all.

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 N6596K · 2

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