Grumman G-164A accident near Nyssa, Oregon, July 23, 2004
On July 23, 2004 at about 2:30 am local time, a Grumman G-164A, registered N7220, was substantially damaged in an accident near Nyssa, Oregon. 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
The failure (fracture) of the number four cylinder head during an aerial application run. Factors include the soft crop-covered terrain.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 23, 2004 · about 2:30 am local time
- Place
- Nyssa, Oregon · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Grumman G-164A · all G-164As on the register
- Registration
- N7220 · registry record · serial 896
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
During an aerial application run, the pilot heard a loud bang, and the engine suddenly lost a significant amount of power. Because the aircraft did not have enough power to remain airborne, the pilot elected to execute a forced landing in a nearby agricultural field. Although the initial touchdown was uneventful, the main gear of the aircraft dug into the soft terrain, leading to a main gear collapse and a nose-over of the aircraft. It was ultimately determined that while the aircraft was in flight, the number four cylinder head had fractured near where the cylinder head was screwed into the cylinder barrel, and the fracture was of such a nature that it kept the cylinder from developing the compression necessary for detonation of the fuel/air mixture.
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
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 26,025 hours in all; 150 in the last 90 days
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rear
- Injury: minor injuries
The aircraft
- Maximum gross weight: 4,500 lb
- Seats: 1
- Landing gear: fixed
- Engine: Pratt & Whitney R-985 (piston); 0 hours total
The flight
- Departed from: Nyssa ID
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 270° at 10 knots
- Visibility: 20 statute miles
- Sky: clear
- Temperature: 90°F (32°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.
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.