In response to the findings of the June 8 helicopter crash in a lava field on South Point, the National Transportation Safety Board issued urgent recommendations on Friday for immediate and more frequent inspections of tail boom components on Bell 407 aircraft.
In the Big Island crash, the tail boom separated from the fuselage of a Bell 407 during a sunset tour operated by Paradise Helicopters out of Kona.
The 54-year-old pilot and 19-year-old passenger in the co-pilot seat were seriously injured, while the four passengers in the back walked away from the crash in a remote area of the island.
NTSB Chair Jennifer Homendy said the Bell 407 helicopter is a popular model among tour operators, police departments, air ambulance providers and others.
“[This] is why our finding is so urgent,” she said. “We’re calling on regulators to act immediately – before there’s another accident.”
In the Big Island accident, investigators located the tail boom more than 700 feet from the rest of the helicopter.
According to the pilot, about 30 minutes into the flight, the helicopter began an uncontrolled spin to the right. A passenger reported that as the helicopter continued to spin, she observed something fall off the helicopter. The pilot made two May Day calls and told his passengers to brace for a hard landing as he tried to level the helicopter, which continued to spin uncontrollably until it crashed on the lava field.
An examination of the helicopter wreckage revealed that the upper left attachment hardware, one of four fittings that attaches the tail boom to the fuselage, was missing and could not be located at the accident site. The remaining three fittings and hardware were found with the tail boom. One fitting had multiple fatigue fractures and two fittings had overload fractures.
The NTSB is urging the United States’ Federal Aviation Administration and Transport Canada to require immediate inspections of the tail boom attachment hardware and fittings.
The NTSB also said the 300-hour inspection interval the manufacturer required for the tail boom attachments may not detect missing or fractured hardware before the tail boom separates from the fuselage. It said the inspections should be done more often.
This was based on the crash investigation that found the accident occurred just 114 hours following the last inspection of the crashed Paradise helicopter, which did not turn up any anomalies.