A steel building frame lifted by a helicopter from a Frankton yard this week crashed about eight metres to the ground.
Alpine Choppers was taking a frame from Shotover Engineering on Tuesday morning to the Jagged Edge building site, high above the Glenorchy Road.
The hovering chopper dropped its load shortly after picking up the frame.
It’s understood a sharp edge on the steel cut the strop holding it in place.
Alpine Choppers boss Brendan Thow says there was webbing to alleviate the sharp edge “but it didn’t quite cut the mustard, I guess”.
It was good the load fell where it did rather than “down the track”, Thow says.
Shotover Engineering boss Nigel Davy says none of his staff were in danger from the falling portal, which weighed almost 800kg.
“The guys had followed their safety plan and they were clear.”
The way it fell upside down, which twisted it, “made it look really bad”, he adds.
Davy confirms Civil Aviation Authority and Department of Labour are investigating the incident.
“Whether we [air] lift from here is up to whatever their findings are.”
CAA spokesman Bill Sommer says the case has been handed to a safety investigator. “It’s an under-strung load from a helicopter and it’s covered by our rules.
“It seems to be an unusual incident – very few of these seem to have been reported to us.”