Grumman G164 accident near Sutter, California, May 5, 2019
On May 5, 2019 at about 5:06 pm local time, a 1984 Grumman G164, registered N3630D, was substantially damaged in an accident during enroute (cruise) near Sutter, California. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A loss of engine power due to the in-flight separation of the fuel control unit interconnect rod for reasons that could not be determined due to lack of available evidence.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 5, 2019 · about 5:06 pm local time
- Place
- Sutter, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Grumman G164 B, built 1984 · all G164s on the register
- Registration
- N3630D · no longer on the register · serial 756B
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
Shortly after the pilot transitioned from climb to cruise flight, the engine power suddenly decreased to idle power without any control inputs from the pilot. He attempted to cycle the throttle to restore power but was unsuccessful. The pilot jettisoned the fertilizer payload he was carrying and initiated a forced landing to a nearby dirt road. The airplane impacted the ground short of the road and collided with trees before it came to rest, substantially damaging the wings and fuselage. The engine continued to run at idle power after the airplane came to rest. Examination of the airplane found that an interconnect linkage between the fuel control unit (FCU) and propeller governor had separated from its mount and the bolt, nut, spacer and cotter pin normally used to secure the FCU interconnect rod to the FCU actuating lever were missing. Additionally, the cam designed to adjust the FCU and propeller governor conditions simultaneously through cockpit control inputs had fractured. This fracture was the result of overstress and likely occurred after the interconnect linkage separated. Based on the design of the FCU, it is likely that the loss of power occurred when the FCU interconnect linkage disconnected in flight, which caused the FCU to revert to its idle power condition. The engine examination revealed no further anomalies, and the pilot reported that the engine continued to function on idle power after the airplane came to rest. As maintenance records indicated that the FCU intermediate linkage had recently been removed, it is likely that maintenance personnel disconnected the interconnect rod for easier access to the FCU. However, as the securing hardware was not recovered, the actual circumstances that led to the separation of the bolt, nut, and washer from the FCU could not be determined.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Powerplant sys/comp malf/fail during enroute (cruise) defining event
- Loss of engine power (total) during enroute (cruise)
- Collision with terrain or object (not controlled flight into terrain) during landing
The NTSB's findings
- cause Aircraft › Aircraft power plant › Power plant › (general) › Failure
- cause Aircraft › Fluids/misc hardware › Misc hardware › Fasteners › Not specified
- Not determined › Not determined › (general) › (general) › Unknown/Not determined
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land
- Flight time: 5,409.7 hours in all; 4,213.3 in this make and model; 103 in the last 90 days; 85 in the last 30 days; 5,359.6 as pilot in command
- Last flight review: January 5, 2019
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: sngl
- Injury: no injuries
The aircraft
- Airframe total time: 13,561 hours
- Last inspection: annual inspection, March 20, 2019; 55 hours since
- Seats: 1
- Landing gear: fixed
- Engine: Pratt And Whitney PT6-34AG (turboprop); 13,646 hours total
The flight
- Departed from: PRIV Robbins CA at 5:05 pm
- Destination: PRIV Robbins CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 170° at 5 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 61°F (16°C), dew point 48°F (9°C)
- Altimeter: 29.81 inHg
- Observation at 4:53 pm from KMYV, 8 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
6 documents, released by the NTSB on April 25, 2022. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Materials Laboratory Factual Report 20-012 | PDF, 2 pages | View Download |
| 2 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 3 | Record of Conversations | PDF, 4 pages | View Download |
| 4 | NTSB Examination Report | PDF, 7 pages | View Download |
| 5 | Aircraft Logbook Excerpt | PDF, 3 pages | View Download |
| 6 | Accident Photographs | PDF, 2 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N3630D the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.