NTSB SEA92LA191 — 1992-08-25 · EDMONDS, Washington, United States

Current FAA registration · N4431U

Make / Model: HELIO H-391B
Seats / Engines: 4 seats · 1 engine
ADS-B equipped: Yes — Mode-S A55850

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

N4431U Helio H-391B None

Probable cause & findings

THE PARTIAL LOSS OF ENGINE POWER WHEN AN EXHAUST VALVE SEIZED IN THE OPEN POSITION AND THE WATER WHERE THE PILOT WAS FORCED TO LAND, WHICH RESULTED IN AN ACFT NOSE OVER ON TOUCHDOWN.

Factual narrative

THE PILOT INCREASED POWER TO INITIATE A CLIMB AND THE ENGINE PARTIALLY LOST POWER. HE DITCHED THE ACFT IN PUGET SOUND WHEN HE WAS UNABLE TO REACH AN AIRPORT OR THE SHORE FOR AN EMERGENCY LANDING. THE ACFT NOSED OVER ON TOUCHDOWN IN THE WATER. AN EXAM OF THE ENGINE AFTER THE ACCIDENT REVEALED THE NO 4 EXHAUST VALVE WAS SEIZED IN THE OPEN POSITION. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1992_SEA92LA191.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

Search this event elsewhere

External sources are reported, not agency: signal that something happened, not fact about what happened.