Mr McKenna, who has lived in Featherston all his life, joined the brigade after a workmate "put on a bit of pressure" to join up.
His brother was in the brigade, and he can recall an uncle who also served. Now, after 40 years, all four of his children have followed him into the brigade.
Mr McKenna, who became the fire chief in 1996, has a very high attendance percentage - in the "high nineties", he reckons.
By day he's a mechanic at Adamson Service Station, and he thanks his generous employers for allowing him to attend every call-out.
"Brian and Lily, they have to be such community-minded people, because they have allowed me to go to every fire call, and they pay me for the time.
"I've really appreciated it."
He said he still gets the same adrenalin rush as he did 40 years ago, when the siren goes.
If it's at night, his partner turns on the lights and holds the door open for him.
"As soon as the siren goes, you never know, every call is different.
"You meet up with the guys at the door.
"It's the comradeship. It's about putting something back into the community.
"If you want to do something for the town, it's a good way to do it."
Back in the 70s, it was all about fighting fires, with perhaps 50 to 60 calls a year.
Last year, the Featherston brigade attended 151.
In storms and high winds, they can get 25 calls in one day, to deal with roofing.
The brigade's proximity to the Rimutaka Hill Rd and two State Highways means attending serious crashes - some tragic.
"We see some pretty horrific crashes, no two ways about it," said Mr McKenna.
"I don't have a problem with it, but I'm lucky to feel that way.
"It's the nature of the job."
The brigade is expected to attend medical calls, because their response for a South Wairarapa call-out is quicker than the ambulance, stationed out of town.
His last call, prior to the interview, was to give someone CPR.
He said he's happy to keep going in the role.
"I've been here all my life, I'm quite happy at what I'm doing.
"I still feel pretty good, so why not."
