CEN23LA232 · Grumman Acft ENG COR-Schweizer G-164B
Grumman Acft ENG COR-Schweizer G-164B · Accident during takeoff
From Bloomfield Municipal Airport (84Y) to Bloomfield Municipal Airport (84Y)
Event
- NTSB case
- CEN23LA232
- 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
- Event fatalities
- Unknown
- 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 Acft ENG COR-Schweizer G-164B
- Aircraft type
- Grumman 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
- N48485
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Bloomfield Municipal Airport (84Y), Bloomfield, NETo Bloomfield Municipal Airport (84Y), Bloomfield, NE
- Aircraft age
- About 47 years (built 1976)
- 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
- Takeoff
- Defining eventThe 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
- Unknown or undetermined
- 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
- Aircraft › Aircraft power plant
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The operator reported that the first flight of the day was completed without incident. However, during takeoff for the second flight of the day, the airplane started to lift off the runway but would not climb. The pilot applied full throttle, but the engine did not respond. The airplane went through a fence off the end of the runway and came to rest in a soybean field which resulted in substantial damage to the upper and lower right wings.
An engine examination did not reveal any evidence of an uncontained failure or external fire damage. The engine contained multiple indications of power at the time of impact, such as rotational scoring damage by the compressor impellers and turbine blades and earthen material present within the engine. In addition, the torsion shaft was fractured in torsional overload resulting from sudden stoppage due to impact of the propeller.
Bench testing determined that the fuel control unit (FCU) cam initially moved axially as the compressor inlet pressure (Pt2) was increased but then stopped moving. Upon disassembly of the fuel control unit, the cam gear was seized in position on the shaft. Metallurgical examination of the camshaft found two depressions on opposite corners of the camshaft slot. The outer camshaft diameter was larger than the specified diameter in the area of the two depressions. The bushing exhibited corresponding areas of wear and distinct gouges along the axis of the bushing and on either side of the shaft slot. One gear tooth on the camshaft exhibited signs of spalling damage and cracking across the entire length of the tooth.
The FCU camshaft deformation may have restricted cam translation, which would have reduced metered fuel flow. However, if the camshaft was restricted, the condition would have been present on previous flight(s) since the camshaft translation was a function of altitude changes. It is unlikely that the FCU contributed to the lack of throttle response.
A fuel sample taken from the fuel filter bowl consisted of Jet A fuel and water. However, the quantity of water was not consistent with any degradation of engine performance.
The investigation was unable to determine the reason for the reduction of engine power during the accident takeoff.
Probable cause
A partial loss of engine power during takeoff for reasons that could not be determined.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN23LA232
- Event ID
- 20230607192330
- Case number
- CEN23LA232
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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, cause areas. 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: 4060c5abe02006c6eb30b2cba48d3acba2a41af8401bedf11d53f6a4cbdfd6ff; retrieved 2026-09-16T17:42:17.417Z.