Investigators will look at whether thick smoke was partly to blame for a firefighting helicopter crash in regional Victoria which temporarily grounded similar aircraft across Australia.
The foreign crew of two pilots and an engineer were re-filling the 6000-litre Sikorsky S-64E Skycrane when it crashed into a dam about 7pm on Monday while fighting the Thomson Catchment Complex fires in remote Gippsland.
The trio has since been released from hospital with minor injuries.
"Fortunately they were close to the water so they haven't fallen a great deal," Department of Environment, Land, Water and Planning deputy chief fire officer Darrin McKenzie told reporters near the scene on Tuesday.
The highly-trained crews from Canada and the US spend southern hemisphere summers working in Australia.
"It would have been a significant shock, as you would expect, but their training stood them in good stead and as I said, that kicked in straight away and they were able to swim to the shore where they were able to receive medical attention," Mr McKenzie said.
The helicopter remains in the dam and authorities, along with aircraft operator Kestral, are co-ordinating a retrieval.
"The helicopter collided with water and came to rest inverted resulting in minor injuries to the three crew and damage to the helicopter," reported the Australian Transport Safety Bureau, which is investigating the crash along with WorkSafe under the lead of police.
The probe will interview witnesses and crew, collect and examine flight data and check operation and maintenance procedures and manuals.
"There's a number of hazards, obviously smoke and visibility and operating in a smoky environment," Mr McKenzie said of the challenges facing firefighting pilots.
"This particular (terrain) was surrounded by a forest and it was quite steep."
Early on Tuesday Emergency Management commissioner Andrew Crisp said the crash had meant the grounding of Australia's other S-64E Skycranes, including two in NSW, one in South Australia, and a second in Victoria.
The aircraft were cleared for use by late afternoon.
Severe fire conditions are predicted for the state on Wednesday, with warnings in place in the Mallee, Wimmera and South West regions.
Melbourne can expect a top of 37C with northwest centres pushing 40C.
