DFW05CA186 · Grumman-Schweizer G-164A
Grumman-Schweizer G-164A · Accident: partial loss of engine power (mechanical failure) while maneuvering
From Red Beard Dusting Service Airport (9LS5) to an unrecorded destination
Event
- NTSB case
- DFW05CA186
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Grumman-Schweizer G-164A
- Aircraft type
- Grumman Schweizer G-164
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N8891H
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Red Beard Dusting Service Airport (9LS5), Tallulah, LATo not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 137: Agricultural
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Maneuvering · aerial application
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Partial loss of engine power (mechanical failure)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Engine assembly, cylinder › Fractured
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
At the completion of an east to west spray pass over a field, the bi-wing agricultural airplane's engine experienced a loss of power and exhibited an unusual vibration. The 2,697-hour private pilot turned the airplane in a southerly direction in an attempt to fly back to the originating airport. Realizing that the engine was not developing sufficient power to return to the airport, the pilot turned the airplane approximately 180-degrees towards a road that he thought would make a suitable landing area. Before the pilot could reach the road, the engine started making "popping" noises, trailing smoke, and experienced a further reduction of power. The pilot then elected to land in a cotton field. During the landing roll the left main landing gear collapsed and the airplane nosed over coming to rest in an inverted position. An examination of the engine revealed the number five-cylinder exhaust valve rocker arm mounting boss was fractured approximately 180 degrees around its circumference. This fracture allowed the exhaust valve to remain closed.
Probable cause
The partial loss of engine power as result of the fracture of the number five-cylinder exhaust valve rocker arm mounting boss. A contributing factor was the lack of suitable terrain for the forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DFW05CA186
- Event ID
- 20050817X01267
- Case number
- DFW05CA186
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 1e77b2980c660bdc474adc0f3177f769b1f235ee776045629aee319066e3a6f8; retrieved 2026-09-21T18:56:59.978Z.