Grumman Acft Eng Cor-Schweizer G 164A accident near Five Points, California, June 21, 2015
On June 21, 2015 at about 1:00 pm local time, a 1975 Grumman Acft Eng Cor-Schweizer G 164A, registered N8598H, was substantially damaged in an accident during takeoff near Five Points, California. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Maintenance personnel’s improper reassembly of the engine during overhaul, which led to the failure of the supercharger-blower due to a lack of lubrication and the subsequent total loss of engine power during takeoff.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 21, 2015 · about 1:00 pm local time
- Place
- Five Points, California · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Grumman Acft Eng Cor-Schweizer G 164A, built 1975 · all G 164As on the register
- Registration
- N8598H · no longer on the register · serial 1429
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, shortly after takeoff for the aerial application flight, the engine lost power. The pilot subsequently initiated a forced landing to a field. The airplane impacted the ground and flipped over. The engine manufacturer's table of limits specified that the minimum side clearance/tolerance between a starter shaft circumference and a starter shaft bushing should be 0.002 inch. However, during postaccident examination, there was no measurable clearance between the starter shaft circumference and the starter shaft bushing, which impeded oil flow to the impeller shaft and bearings and resulted in the failure of the supercharger-blower due to a lack of lubrication. The engine had accumulated 2.0 hours since its last major overhaul, and it is likely that maintenance personnel improperly reassembled the engine during the overhaul.
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 takeoff
- Loss of engine power (total) during takeoff defining event
- Off-field or emergency landing during emergency descent
- Roll over during post (impact)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng supercharger › Failure
- cause Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Maintenance personnel
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land
- Flight time: 18,541 hours in all; 18,141 in this make and model; 75 in the last 90 days; 40 in the last 30 days; 18,341 as pilot in command
- Last flight review: April 15, 2015
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: ctr
- Injury: minor injuries
The aircraft
- Airframe total time: 3,952.8 hours
- Last inspection: 100-hour inspection, July 7, 2014; 2 hours since
- Maximum gross weight: 4,776 lb
- Seats: 1
- Landing gear: fixed
- Engine: Pratt & Whitney R-1340-59 (piston); 3,952 hours total
- Operator: Kennys Crop Dusting INC
The flight
- Departed from: Five Points CA at 1:00 pm
- Destination: Five Points CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 290° at 6 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 63°F (17°C), dew point 39°F (4°C)
- Altimeter: 29.87 inHg
- Observation at 11:56 am from KNLC, 9 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N8598H 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.