On May 26, 1990, a Cessna 172XP (registration N1650V) was involved in an aviation accident near Leona, TX. Investigators recorded the probable cause as: The engine lost complete power because the primary and alternate air inlets became blocked by a rat's nest; the blockage occurred when the air inlet spring failed, allowing the nest to enter the main air inlet throat, causing air starvation. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During cruise, an aircraft's engine lost all power after a rat's nest blocked the air inlets. The pilot performed a forced landing; during the rollout, the aircraft struck three fences. The blockage resulted from a failed air inlet spring.
Introduction
During a cruise flight, an aircraft experienced an abrupt and complete loss of engine power. The power loss was attributed to the blockage of both the primary and alternate air inlets by a foreign object: a rat's nest. This event necessitated an immediate forced landing.
Incident Details
The pilot executed a forced landing to the only suitable area available. The aircraft touched down without incident; however, during the landing roll, it struck three fences. The sequence of events highlights the pilot's successful touchdown but subsequent collision with ground obstacles during deceleration.
Cause
The blockage that led to the power loss occurred when the air inlet spring failed. This failure allowed the rat's nest to enter the main air inlet throat, resulting in air starvation to the engine. Both the primary and alternate air inlets became obstructed by the nest, depriving the engine of the necessary airflow for combustion. The spring failure was the mechanical trigger that enabled the foreign object to reach the intake system.
Probable cause
The engine lost complete power because the primary and alternate air inlets became blocked by a rat's nest; the blockage occurred when the air inlet spring failed, allowing the nest to enter the main air inlet throat, causing air starvation.