| Crash location | Unknown |
| Nearest city | Perris, CA
33.782519°N, 117.228648°W |
| Tail number | N9991F |
|---|---|
| Accident date | 30 Jun 1988 |
| Aircraft type | Helio HST-550A |
| Additional details: | None |
FAILURE OF THE ELECTRICAL STABILIZER TRIM CONTROL THAT RESULTED IN AN UNCOMMANDED FULL NOSE DOWN ELEVATOR TRIM COMMAND.