# Accident 19980518009939A: Gulstm AA5A, Sumpter, SC, May 18, 1998

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: May 18, 1998, 14:20 local time
- Place: Sumpter, SC
- Damage: Substantial damage
- Phase of flight: Fcd/Prec Ldg From Cruise
- Operating rules: General operating rules (Part 91)
- Location: 33.9409° N, 80.3893° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=33.9409&lon=-80.3893&mi=10
- Aircraft: N9884U, a cancelled registration (https://openairdocs.org/deregistered/N9884U-2000-02-01) (OpenAirDocs)
- Registry model: Grumman American Avn. AA-5A (registry code 3960106, https://openairdocs.org/model/grumman-american-avn-aa-5a) (OpenAirDocs)
- Reported make and model: GULSTM AA5A
- Reported engine: LYC O320E2G
- People aboard: 1
- Fatal injuries: 0
- Pilot flight hours: 15,000 total, 30 in this make and model
- NTSB investigation: [NTSB MIA98LA166](https://openairdocs.org/ntsb/MIA98LA166) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19980518009939A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

BIENNIAL FLIGHT REVIEW. NOTED LOW OIL PRESSURE. ROUGH ENGINE. LANDED CROSS FURROW PLOWED FIELD. NOSE GEAR FOLDED.(.4) THE FLIGHT HAD BEEN AIRBORNE ABOUT 30 MINUTES PERFORMING AIRWORK, THEN WHILE FLYING AT 2,000 FEET RETURNING TO THE AIRPORT, THE CFI NOTED THAT THE OIL PRESSURE WAS BELOW THE LOWER END OF THE GREEN ARC. HE QUESTIONED THE OWNER IF THAT WAS NORMAL; IT WAS NOT. THE ENGINE THEN BEGAN TO RUN ROUGH AND BEGAN TO LOSE POWER. ATTEMPTS TO CORRECT THIS WERE UNSUCCESSFUL. THE CFI ATTEMPTED TO PERFORM A FORCED LANDIN IN A FIELD BUT WHILE ON FINAL APPROACH WITH THE THROTTLE STILL APPLIED, ENGINE POWER WAS MOMENTARILY RESTORED. HE THEN OVERFLEW THE INTENDED FIELD AND ATTMEPTED A LANDING IN FRESHLY PLOWED FIELD PERPENDICULAR TO THE PLOWED ROWS. AFTER TOUCHDOWN THE NOSE LANDING GEAR COLLAPSED AND THE ENGINE PARTIALLY SEPARATED FROM THE AIRFRAME. DISASSEMBLY OF THE ENGINE REVEALED NO EVIDENCE OF PREIMPACT FAILURE OR MALFUNCTION. THE OIL COOLER BYPASS VALVE WAS TESTED WHICH REVEALED THAT IT DID NOT MEET THE MINIMUM EXTENSION AT THE MIDPOINT OF THE TEST RANGE. THE ENGINE HAD ACCUMULATED ABOUT 2,091 HOURS SINCE MANUFACTURE WITH NO RECORD OF THE BYPASS VALVE BEING REPLACED.               (-23) THIRTY MINUTES AFTER DEPARTING SUMTER, SC (SMS), THE PILOT NOTICED LOW OIL PRESSURE AND HIGH OIL TEMP. THE ENGINE FAILED AND AN OFF AIRPORT LANDING WAS MADE IN A COTTON FIELD APPROXIMATELY SIX MILES NORTH OF SUMTER, SC (SMS). THE AIRCRAFT SUSTAINED SUBSTANTIAL DAMAGE. THERE WERE NO INJURIES.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB MIA98LA166](https://openairdocs.org/ntsb/MIA98LA166), May 18, 1998: Grumman American AA-5A (N9884U), Sumter, SC, substantial damage. Probable cause: The partial failure of the oil cooler bypass valve which resulted in the over-temperature and loss of oil pressure.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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