Grumman G-164A accident near Walsh, Colorado, August 6, 2008
On August 6, 2008 at about 12:30 pm local time, a Grumman G-164A, registered N7487, was substantially damaged in an accident during maneuvering (low-alt flying) near Walsh, Colorado. 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
The total failure of a cylinder head assembly. Contributing to the accident was the lack of suitable terrain for a forced landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 6, 2008 · about 12:30 pm local time
- Place
- Walsh, Colorado · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Grumman G-164A · all G-164As on the register
- Registration
- N7487 · no longer on the register · serial 964
- 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 was spraying a corn field; as he was making an aerial application pass, a cylinder on the engine cracked and the engine lost power. The pilot made a forced landing in a nearby field. The airplane crossed a road at a speed of approximately 25 mph and the tail bounced up. After crossing the road, the main tires settled into soft earth and the airplane nosed over. In addition to a bent propeller and "minor top wing damage," the vertical stabilizer was crushed.
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 maneuvering (low-alt flying) defining event
- Off-field or emergency landing during maneuvering (low-alt flying)
- Nose over/nose down during landing (landing roll)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Failure
- factor Environmental issues › Physical environment › Terrain › Rough terrain › Ability to respond/compensate
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land
- Flight time: 2,500 hours in all; 1,003 in this make and model; 110 in the last 90 days; 30 in the last 30 days; 2,400 as pilot in command
- Last flight review: March 1, 2007
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: sngl
- Injury: no injuries
The aircraft
- Airframe total time: 5,821 hours
- Last inspection: annual inspection, January 1, 2008; 690 hours since
- Maximum gross weight: 4,500 lb
- Seats: 1
- Landing gear: fixed
- Engine: Pratt & Whitney R1340-AN-1 (piston); 0 hours total
- Operator: Doyles Ag Services LLC
The flight
- Departed from: NONE Two Buttes CO at 12:00 pm
- Destination: NONE Two Buttes CO
- Flight plan: none
Weather at the time
- Light: dawn
- Wind: from 200° at 4 knots
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 68°F (20°C), dew point 0°F (-18°C)
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.
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.