On May 20, 1982, a Bell 47G-1 (registration N141B) operated by Mort Rabkin was involved in an aviation accident near Cincinnati, OH. Investigators recorded the probable cause as: The pilot's intentional collision with trees during a forced landing, which resulted from the disconnection of the fore and aft cyclic control linkage tube due to a missing pivot bolt (part number AN-174-15). This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot executed a controlled crash into trees after the cyclic control linkage tube disconnected in flight, citing the impact as a means to cushion the descent.
What happened
The aircraft experienced an in-flight separation of the fore and aft cyclic control linkage tube. Following this mechanical failure, the pilot initiated an emergency descent procedure. To manage the situation, the pilot utilized collective "S" turns specifically designed to reduce airspeed during the approach.
During the forced landing phase, the pilot made a deliberate decision to collide with trees. This action was taken intentionally to cushion the fall and mitigate the impact forces upon ground contact.
The investigation
Post-accident examination of the aircraft revealed the root cause of the control loss. Investigators found that the cyclic pivot bolt, specifically part number AN-174-15, was missing from the assembly. This absence allowed the linkage tube to disconnect while the aircraft was airborne.
Probable cause
The pilot's intentional collision with trees during a forced landing, which resulted from the disconnection of the fore and aft cyclic control linkage tube due to a missing pivot bolt (part number AN-174-15).