Casualties unknown

Forced Landing After Power Loss Due to Blocked Fuel Vent (N5428D)

Boulder, CO, US

On September 19, 1996, a Beech H35 (registration N5428D) was involved in an aviation accident near Boulder, CO. Investigators recorded the probable cause as: Blocked fuel vent due to mud-based insect nest. 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

Aircraft experienced total power loss at 200 feet during touch-and-go, leading to forced landing on rough terrain. Investigation revealed blocked fuel vent from mud-based insect nest, not visible during normal inspection.

Incident Overview

During a flight, at an altitude of 200 feet above ground level, following a touch-and-go landing, the aircraft suffered a total loss of engine power. The pilot conducted a forced landing, which resulted in the aircraft coming to rest on rough and uneven terrain.

Examination Findings

Subsequent examination of the aircraft provided evidence that the left fuel tank, which had been selected, had a totally blocked fuel vent. The blockage was caused by a mud-based insect nest located internally within the vent. The nest could not be seen during normal inspection due to its internal position.

Additional Context

The aircraft had not been flown in the 20 days prior to the accident flight. No other factors were identified in the examination.

Probable cause

Blocked fuel vent due to mud-based insect nest.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001208X06736. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.