A battered medicine chest and an original pedal wireless are on display at the National Museum of Australia (NMA) to commemorate the 90th anniversary of the Royal Flying Doctor Service (RFDS).

The metal chest contains bottles of laxatives, pain tablets and antiseptic cream well past their use-by dates.

"It just makes me smile," said RFDS chief executive Martin Laverty as he viewed the display in the museum's Landmarks Gallery.

"We're reminded about how things have changed, but nothing has changed at all.

"The Flying Doctors is both still here, but more importantly still needed."

The medicine chests were packed with essential items. ( Supplied: National Museum of Australia )

The medicine chest was one of many that were packed and flown to outback stations and remote communities in the mid-20th century.

The RFDS still dispenses similar sturdy boxes across rural and remote Australia.

"[They have] to be that tough to survive in the back of a ute ... in the back of a tractor," Dr Laverty said.

Overcoming the barrier of distance

The RFDS, originally known as the Australian Inland Mission Aerial Medical Service, was founded by Presbyterian minister John Flynn in Cloncurry, Queensland, in 1928.

His vision was to create "a mantle of safety" for isolated people in the outback.

In 1929 the RFDS introduced the first pedal wireless, invented by Adelaide engineer Alfred Traeger, which revolutionised communication.

As well as its crucial role in medical care, it paved the way for distance education through the School of the Air.

The pedal wireless invented by Alfred Traeger was a crucial communication tool. ( Supplied: National Museum of Australia )

"It was hooked up to the transceiver," NMA curator Laina Hall said.

"The pedal ... generated the electricity which ... enabled the transceiver to transmit and receive messages.

"There's this lovely phrase 'pedal and puff', because you needed to really give it a good go."

The museum's interactive display also includes early manuals, medical equipment and video stories from a clinician, a patient and a pilot.

Ms Hall's favourite object is a 1950s RFDS sign from the Cloncurry base, emblazoned with the words "medicine", "aviation" and "radio".

"That sums up the RFDS story," she said.

"It was those three key features which allowed people in remote communities to be connected to medical aid but also through radio with each other."

The RFDS artefacts will be on display at the National Museum until 2023. ( Supplied: Jason McCarthy, NMA )

From biplanes to telehealth

After starting with one leased biplane in 1928, the RFDS now has a fleet of 69 aircraft and 115 road vehicles.

More than 1,400 professionals deliver primary and emergency care to around 350,000 patients a year.

Dr Laverty said the organisation was considering how to meet the increasing demand for mental health services caused by the pressures of the drought.

"People in country Australia see doctors at about half the rate of people who live in the city," he said.

"When it comes to medical specialists, they see them at a third the rate, and when we come to mental health it's only one-fifth the rate of people who live in the city."

Dr Laverty said he hoped visitors to the museum appreciated the RFDS's rich history and the ongoing medical support it provided, from delivering supplies to telehealth and emergency evacuations.

"It's so important that we continue to provide access to health care to people who live in the bush."