A married couple who were expecting a baby have died after their light aircraft crashed in bad weather in north Queensland.

The wreckage of the plane that had been carrying stockman Rhiley Kuhrt and his pregnant wife Maree was spotted by a rescue helicopter crew on Monday morning after it was reported missing on Sunday night.

The crash site is in rugged terrain in the Mount Hector range, about 30km southwest of Proserpine.

The Piper Cherokee was reported missing after failing to arrive at Lakeside Airpark, Proserpine, by 6.30pm on Sunday. 

Police Inspector Andrew Godbold says preliminary investigations suggest visibility was poor when the plane crashed.

“A lot of showers, thunder and probably visibility down to nothing,” he told reporters in Mackay.

Insp Godbold indicated the retrieval mission will take two to three days with local State Emergency Service crews helping the operation. 

“It’s a very rugged terrain there. There’s obviously a lot of mountainous terrain in the area there and it is very difficult for us even just to walk in at this stage,” he said.

The bodies are yet to be formally identified and the couple’s family has asked for privacy. 

Australian Transport Safety Bureau investigators are travelling to the crash site to collect evidence, including any recorded data, weather information and will also seek witness reports and aircraft operator procedures and maintenance records.

The agency expects to publish a preliminary report in six to eight weeks and with a final report detailing contributing factors and any identified safety issues.

“Should any critical safety issues be identified at any stage during the course of the investigation, the ATSB will immediately notify relevant parties so appropriate safety action can be taken,” it said on Monday afternoon.