FTW98LA171 · Aero Commander S2R
Aero Commander S2R · Accident: total loss of engine power (mechanical failure) during initial climb
From Cushing Municipal Airport (CUH) to an unrecorded destination
Event
- NTSB case
- FTW98LA171
- 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
- 0
- 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
Aero Commander S2R
- Aircraft type
- Aero Commander S2
- 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
- N8984Q
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Cushing Municipal Airport (CUH)To 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 91: General Aviation
- 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
- Initial climb
- 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
- Total 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
- Accessory drive assembly, drive shaft › Sheared
- Reason for occurrence undetermined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
During the initial takeoff/climb a loss of manifold pressure was noted by the pilot. The engine backfired as the pilot increased the throttle and mixture and lost power. During the forced landing, the pilot maneuvered the airplane to avoid power lines and homes. The main gear collapsed as the airplane touched down hard in an open field. Examination revealed that the mixture control arm at the carburetor was loose; however, the nut and cotter key were intact. The mixture control in the cockpit was full forward; however, the mixture control at the carburetor was set at less than 50 percent travel toward the rich stop on the carburetor. Engine continuity was confirmed to the accessory case; however, neither magneto rotated when the propeller rotated. A mechanic stated that this lack of magneto rotation indicates that the accessory shaft has sheared inside the rear case of the engine. The carburetor and engine were not disassembled, therefore, it was not determined whether the damage to the mixture control and the drive shaft were preexisting or impact related.
Probable cause
The total loss of engine power resulting from a sheared accessory drive due to an undetermined reason. A factor was the lack of suitable terrain for the forced landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW98LA171
- Event ID
- 20001211X09851
- Case number
- FTW98LA171
- 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. 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: dbcc29bc960896d139cfff4344904029a944e98dffe4deacee57bd9a341809cd; retrieved 2026-09-22T17:54:37.287Z.