Casualties unknown

Engine Misfire and Smoke Prompt Forced Landing; Muffler Corrosion Found (N5611Z)

Dorado, PR, US

On March 14, 1988, a Piper PA-22-108 (registration N5611Z) was involved in an aviation accident near Dorado, PR. Investigators recorded the probable cause as: WHILE ON A PERSONAL FLT IN NORMAL CRUISE AT AN ALT OF 1000 FT APRX 2 MILES SOUTHEAST OF THE ARPT, THE ENG BEGAN TO MISFIRE AND THE CABIN FILLED WITH SMOKE. THE PLT ELECTED TO LAND IN A CLEARING. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

During cruise at 1,000 ft, the engine misfired and smoke filled the cabin. The pilot landed in a clearing, but the nose gear broke during the landing roll, causing the aircraft to nose over. Investigation revealed pin-size rust holes in the muffler that allowed exhaust to burn through the shroud and damage wiring.

Event Description

While on a personal flight in normal cruise at an altitude of approximately 1,000 feet, about 2 miles southeast of the airport, the engine began to misfire and the cabin filled with smoke. The pilot elected to land in a clearing. The pilot stated that the engine was losing power and that the aircraft could not maintain altitude. During the landing roll, the nose gear broke off after hitting a small rise in terrain. The aircraft nosed over and came to rest.

Investigation Findings

Post-crash inspection revealed that the muffler had several pin-size rust holes, which permitted exhaust gases to burn through the shroud. This exhaust damaged insulation on the left magneto wiring harness, voltage regulator wiring, and battery wires from the generator. After replacing the magneto wiring harness, an engine run-up was accomplished with no problems noted. The muffler shroud was made of aluminum rather than stainless steel.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X25305. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.