Find yourself sick or injured in remote WA and a flash of red in the sky could signal salvation.
The Royal Flying Doctor Service has four new planes as part of its fleet upgrade, each with bright red underbellies.
RFDS chief executive Grahame Marshall said the colour scheme was part of rebranding in the organisation's national colour.
"Over the past five years patient demand has increased 8 per cent, which means another 600 to 700 people," Mr Marshall said. "There are 14 PC12 aircraft in our fleet and we hope to bring that to 18 in the next 10 years."
The service replaces its planes every 10 years and each did about 1500 to 1600 hours a year.
The four updated Pilatus PC12 planes had better night vision capabilities and could land on any strip - dirt or bitumen.
BHP Billiton chipped in $4.5 million for the four planes, which cost about $22 million in total.
Mr Marshall said the RFDS was most often used in resources areas, which made the BHP contribution fitting.
"We mostly go to Port Hedland, Broome and Derby. There are not a lot of mine incidents but there are a lot of people around those areas who get sick," he said.
BHP head of community and indigenous affairs Richard O'Connell said health services were a key to attracting workers and their families to an area.