He decided to stay in the military for a bit longer so he had a 20-year career behind him, gain more experience and skills, yet still be young enough to enter the political domain with lots of energy for the long haul.
When Ōtaki MP Nathan Guy announced he was retiring from politics in the upcoming elections, Costley felt the time was right to put his hand up especially as he had "something unique and strong to offer".
He entered the party's electorate selection process in November last year against other aspirants and became the new candidate.
"One of the things I talked about, right back to selection, was a bit of the breakdown of community.
"I think we saw bits of that coming back and being restored during lockdown when people were looking after their neighbours.
"But it's a really broad thing, not a specific policy, it's about building up our community and supporting it."
Costley grew up in Palmerston North, went to Palmerston North Boys High, then Massey University where he studied mathematical physics, before joining the Air Force.
Tim Costley gives young Cameron O'Keeffe, 10, a few pointers during an Air Force display in Whanganui in 2004. Photo / NZ Herald
"The Air Force had always had an appeal.
"Dad took me to the air shows, he talked about how my grandfather had been in the Air Force in the war, and I just always looked up at those guys and wanted to be one of them when I grew up, and I never grew out of that."
The Wing Commander has spent the past 19 years in the Air Force, as a helicoper pilot. He also taught how to fly planes at Ohakea.
"[I] was second in charge of the pilot training squadron and then was in charge of the NH90 [multi-role military helicopter].
Tim Costley with the Duchess of Cambridge during the 2014 royal visit to New Zealand.
"So search and rescue, things like that, and flew overseas, peacekeeping in East Timor and the Solomon Islands.
"Went to Afghanistan, for a few months, as well as Papua New Guinea where I was the sole Kiwi planning elections with a couple of Aussies.
"Fiji after Cyclone Winston, and did my masters in the United Kingdom.
"So fantastic career, predominantly flying helicopters, and with the Air Force you end up wherever they tell you.
"A lot of it has been in Ohakea, couple of times Wellington, and overseas."
His focus is now solely on the Ōtaki electorate with the strong support of his wife Emma and their primary-school aged children Lucy, Rebecca and Alice.
Tim Costley with wife Emma and children Becky, left, Lucy and Alice.
Electorate-wise, he's keen on helping businesses, especially small businesses, recover from the Covid-19 setback, is backing big infrastructure projects like Transmission Gully, and the Ōtaki to North Levin expressway, is advocating for a full interchange at Peka Peka, rail links to Levin and better access to health services as well as attracting health professionals to the area.
"With that will come huge growth and opportunity."
Costley, who likes to keep fit and listen to music when he's got some time to himself, has been very busy getting out and about meeting people, listening to concerns, and keeping in touch with Guy, who has held been the Ōtaki MP for 15 years.
Nathan Guy, left, and Tim Costley at the recent Horowhenua AP&I Show.
"He's been great and a fantastic support to me.
"Big gumboots to fill but I'm keen to do what I've done in my military career and put my best foot forward and work hard."
