On April 4, 2005, a Cessna 421B (registration N637SC) was involved in an aviation accident near Lake Havasu Cit, AZ. No fatalities were reported. Investigators recorded the probable cause as: The roll pin (part number NAS561P4-28) that retains the attaching shaft to the trunnion assembly fractured and failed, allowing the landing gear attaching shaft to shift from its installed position and causing the trunnion assembly to separate from the… This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
After a suspected landing gear malfunction, a pilot returned for a precautionary landing. The left main gear collapsed during a turn. Post-accident examination revealed a fractured roll pin caused the trunnion assembly to separate.
Incident Overview
A pilot experienced a potential landing gear malfunction after takeoff and returned to the departure airport. Following a low approach with the gear up, maintenance personnel confirmed that the left main landing gear was extended. The pilot then cycled the gear down and verified that the landing gear indicators showed the gear was down and locked.
Landing and Collapse
The pilot conducted a soft field landing and allowed the aircraft to roll to the end of the runway. As he began a left turn, the left main landing gear collapsed.
Post-Accident Examination
A post-accident examination of the landing gear assembly found that the roll pin (part number NAS561P4-28), which retains the attaching shaft to the trunnion assembly, had fractured and failed. This failure allowed the landing gear attaching shaft to shift from its installed position, resulting in the trunnion assembly separating from the landing gear support structure.
Probable cause
The roll pin (part number NAS561P4-28) that retains the attaching shaft to the trunnion assembly fractured and failed, allowing the landing gear attaching shaft to shift from its installed position and causing the trunnion assembly to separate from the landing gear support structure.
What happened in the 4 Apr 2005 Cessna 421B accident near Lake Havasu Cit, AZ?
After a suspected landing gear malfunction, a pilot returned for a precautionary landing. The left main gear collapsed during a turn. Post-accident examination revealed a fractured roll pin caused the trunnion assembly to separate.
Were there any fatalities in the 4 Apr 2005 Cessna 421B accident?
No fatalities were recorded in this accident.
What aircraft was involved and where did it happen?
The accident on 4 Apr 2005 involved a Cessna 421B, registration N637SC, at Lake Havasu Cit, AZ.
What was the probable cause of the accident?
The roll pin (part number NAS561P4-28) that retains the attaching shaft to the trunnion assembly fractured and failed, allowing the landing gear attaching shaft to shift from its installed position and causing the trunnion assembly to separate from the landing gear support structure.
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