Maree was 27 weeks pregnant with baby Phoebe, due in June, with pictures of her growing belly proudly shared on social media accounts as they counted down to the new arrival.

On Sunday afternoon, April 2, the couple left Natal Downs Station near Charters Towers in a small plane to attend a planned pregnancy appointment in Mackay.

The couple also hoped to catch up with friends and family after the appointment, but the Piper Cherokee they were in never arrived at the Lakeside Airport north of Mackay.

They had left home in good weather but the plane hit bad conditions, including low cloud around the Clarke Range before it went down.

The wreckage was discovered in dense bushland in the range during an aerial search around 10am on Monday, and both occupants were pronounced dead at the scene.

At the time of the crash, friends described Mr Kuhrt as an experienced pilot who had made the trip safely many times before, but an investigation has revealed he was not licensed.

He was also not familiar with the Piper Cherokee he was flying, with only a handful of hours at the controls before the deadly flight.

An Australian Transport Safety Bureau investigation found Mr Kuhrt was not qualified to pilot the aircraft on the night of the fatal crash and it has discontinued the investigation.

Records from Mr Kuhrt’s flying school showed he had completed 30.4 hours of flight instruction in a year, including 2.9 hours on the Piper Cherokee.

“On that basis, the ATSB determined there was limited safety benefit in continuing to direct resources at this investigation when compared with other priorities,” the bureau said in a statement.

Licensing regulations were designed to ensure pilots were properly trained and equipped to manage challenges likely to be encountered during flights, ATSB Chief Commissioner Angus Mitchell said.

“This includes training intended to teach pilots to identify and manage situations presented by adverse weather, both at the pre-flight planning phase and during flight,” Mr Mitchell said.

“When pilots operate outside the licensing regulations, they remove built-in safety defences.”

Searchers reached the wreckage days later on a steep slope at an elevation of 583 metres.

Despite the investigation being discontinued, Mr Mitchell emphasised important safety lessons and said it demonstrated weather continued to be one of the main causes of plane crashes in general aviation.

“The ATSB encourages all pilots, regardless of qualification or experience level, to develop the knowledge and skills required to avoid unintentional operations into adverse weather.”