On Sunday, a Queensland couple died in a plane crash. They were about to have a baby girl.

Maree Kuhrt was months away from welcoming her first child when she left home with her husband, Rhiley, to attend a pregnancy appointment on Sunday.  

At 2pm, the newlyweds piled into a light plane and took off from the cattle station Natal Downs, near Charters Towers, in Queensland, to fly to Mackay for the appointment.

Just a day earlier, 24-year-old Maree shared a photo on Instagram, counting down the days to her daughter's birth in June.  

"27 weeks now! Getting closer and closer to meeting baby girl," she captioned the post. 

View this post on Instagram

A post shared by Maree Kuhrt (@mkuhrt98)

The pair, who recently relocated to a property near Charters Towers, were due to arrive at Lakeside Airpark at Bloomsbury at 5pm. 

However, they were reported missing at 6.30pm. 

The next morning, the crew of a rescue helicopter discovered the wreckage of their plane in rugged terrain in the Mount Hector range, about 30km southwest of Proserpine. 

Both Maree and Rhiley, a 22-year-old experienced pilot, were pronounced dead at the scene.

Police said preliminary investigations suggest visibility was poor when the plane crashed.

"A lot of showers, thunder and probably visibility down to nothing," Police Inspector Andrew Godbold 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. 

Tributes flow for Maree and Rhiley. 

Since the news broke, friends and family have paid tribute to the couple and their unborn daughter, Phoebe. 

"We are all absolutely heartbroken and utterly grief stricken. Three incredible lives were cut way too short," Rhiley's sister, Beccarah, wrote in a GoFundMe page set up for the family.

Image: GoFundMe

On social media, Maree has been remembered as a "gorgeous soul" who "lit up any room she walked into". 

"The little life they built was the sweetest thing to watch. The world will shine a little less brighter without you three," one friend wrote. 

In another post, a friend paid tribute to Rhiley, who was set to celebrate his 23rd birthday on Wednesday.

"So sad to think it will be your birthday on Wednesday Rhiley and you won’t be here to celebrate it," they wrote. 

"I'm sure everyone will be having a drink for you."

Just months before the crash, Rhiley shared in a Facebook post that he was planning to purchase another aircraft. 

"Gotta set goals in life and my next goal [is] to add to the hanger... a Piper Twin Comanche," he wrote in November, according to 7News.

"Would look good next to my Cherokee."

View this post on Instagram

A post shared by Maree Kuhrt (@mkuhrt98)

An investigation is underway. 

Australian Transport Safety Bureau investigators are currently collecting evidence into the crash, including any recorded data and weather information. They will also seek witness reports and aircraft operator procedures and maintenance records.

The Australian Transport Safety Bureau expects to publish a preliminary report in six to eight weeks.

"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.

- With AAP. 

Feature Image: Facebook@maree.notaras.7