Every now and then you hear a story that sticks in your mind and that was the case for Warrant Officer Mike McDonnell when he met Sergeant Shawn Grimshaw after Sergeant Grimshaw posted into No. 23 Squadron at RAAF Base Amberley earlier this year.

Warrant Officer McDonnell was captivated by Sergeant Grimshaw's story and how Sergeant Grimshaw had managed to balance his 20-year Air Force career with raising his children, including his 29-year-old son, Karl, who has a disability.

"During his inward clearance interview in January, Sergeant Grimshaw shared some of his story with me, including how he has raised his severely disabled son, at times as a single parent, whilst providing full-time service to the Air Force,” Warrant Officer McDonnell said.

"I was blown away by what Shawn had done and continues to do for his son."

When Sergeant Grimshaw joined the RAAF in 2000 as a general service equipment technician, he felt he needed a change, but he never envisaged that over the next 20 years, he'd get divorced, become a single parent, remarry and become a father to a young step-daughter, all while balancing deployments, postings and promotions.

Early in his career, Sergeant Grimshaw experienced the hardship of months away from his wife, son and two daughters, however, it was the breakdown of his marriage in 2010 that lead to Sergeant Grimshaw becoming a single parent to Karl.

"Jess had just started high school and Nikita was in primary school," Sergeant Grimshaw recalled.

"I chanced upon my wife packing up and leaving our house one lunchtime.

"The hardest part was suddenly saying goodbye to my two girls."

To have Nancy walk into my life and just accept everything that I’ve got, including an adult son who needs help with every single thing – I feel really lucky.

As Sergeant Grimshaw launched into the role of being a single parent to his son, he felt the support of the Katherine community rally around him. 

"I got so much community support," he said.

"The local disability support organisation hired staff to take care of Karl and they took him everywhere – to the shops, to the river, around the hospital.

"They spent all day with him while I was at work."

Meanwhile, on weekends, father and son bonded over their love of the great outdoors.

"Karl absolutely loves four-wheel-driving and camping, so we lead a fairly active lifestyle," Sergeant Grimshaw said.

After posting to RAAF Base Darwin in 2016, Sergeant Grimshaw bought a boat to take Karl fishing.

"One day we had an encounter with a 3m hammerhead shark that kept playing around the back of the boat," he said.

"Karl thought the shark was fantastic and I reckon if I hadn't been there, he would have tried to pat it."

Now married to Nancy and stepfather to Krisha, Sergeant Grimshaw feels blessed.

"To have Nancy walk into my life and just accept everything that I’ve got, including an adult son who needs help with every single thing – I feel really lucky," he said.

"My workplace have also been really accommodating for Karl, helping make sure that everything he needs is available to him.

"I couldn’t ask for a better workplace."

Happy Father's Day, Sergeant Grimshaw.