Deductive / Inductive Reasoning

NTSB: Ferry crash caused by malfunction

Deductive / Inductive Reasoning

Deductive reasoning	Inductive reasoning
The malfunction of a solenoid in the propulsion system rendered one of the ships propellers unresponsive to propulsion commands (Valid reasoning if the solenoid is the sole control of the propellers)	The ferry Andrew Barberi slammed into the St George terminal (strong argument, dock damage, injury to persons)
An audio / visual alarm to warn the crew if the propeller was not responding may have prevented the incident (Valid the ferry could have been steered away from the dock if there was time)	Pilot house crewmembers were unaware of the loss of propulsion control (weak reasoning, ferry speed would be visual if the crewmembers were watching)
Audio visual alarms are not required on vessel types such as the Barberi (invalid, even though audio visual alarms are not required, they can still be fitted as a safety devise)	Andrew Barberi was involved in a previous incident in 2003 (weak reasoning, the previous accident had no bearing on this accident)
Safety management systems had improved since the 2003 incident (invalid, safety management systems couldn’t have prevented engineering design / mechanical failures)