Peacefully entered God’s loving arms on Jan. 3, 2022, at the age of 89, surrounded by his wife and family in Milwaukee, Wis.

Loving husband of Mary, (née Singer), for 68 years.

Devoted father of Teresa Platner-Sherman (John Sherman), Karen (John) Farley, Susan Platner (Joe Shemky), Tom (Janet) Platner, Jean (Ty) Holz and Patricia (Tim) Fredman.

Proud grandfather of Danielle Sherman, Bryan Farley, Adam Farley, Jenna (Mike) Mersch, Sarah (David) Sandager, Laura (Nick) Malahy, David Platner, Megan Platner, Jack Holz, Jadyn Holz, Alexina (Garrett) Gosh, Ben Fredman, Sam Fredman and Jorin (Lee) Mattox.

Great-grandfather to Michael Mersch III, Chloe Sandager, Milo Sandager, Rory Malahy, Jack Malahy, Maximus Gosh, Cecily Gosh and Gemma Gosh.

Preceded in death by brothers, Donald Platner, Lyle Platner; and sister, Doris Platner.

A special thank you to the staff at Dickson Hollow for the loving care you provided.

Heartfelt gratitude to Skip, who kept the Moon Lake property and buildings well-maintained, as well as Jack and Mary laughing and on their toes.

Jack was born to Leland and Irma (Mundshau) Platner Oct. 13, 1932.

He attended Whitewater High School and went on to UW-Madison to study engineering as part of the Air Force ROTC program.

He met his wife, Mary whom he married the day after graduation and then served in the U.S. Air Force as a Captain and Navigation Officer flying B-52 missions.

Upon discharge, he began his career with Allis Chalmers.

In the 1960s, he managed the Greendale R&D Plant, which received a NASA contract to manufacture and design a more efficient fuel cell as part of the Apollo program.

Jack’s research department also built the world’s first fuel cell-powered tractor, currently curated by the Smithsonian.

Jack concluded his career as CEO & President of Svedala Industri AB - NA Operations.

Jack and Mary were both pilots and flew a Cessna Cardinal airplane.

They would fly “up North” looking for the perfect location to build their retirement home which they found on Moon Lake and proceeded to build an “Octagon House” which Jack designed himself.

Jack also built two experimental amphibious airplanes which are still flying today.

Jack and Mary enjoyed traveling the world including far-off destinations of the Galapagos Islands and Antarctica.

Jack was instrumental in the building of St. Peter’s Catholic Church in Eagle River, Wis.

He also helped establish St. Peter’s Thrift Shop Annex where they volunteered for 10 years.

What Jack enjoyed the most was being surrounded by his family, his golden retrievers, and taking joy in the beautiful lake and woods surrounding their home.

A Celebration of Life will be held this summer. In lieu of flowers please send donations to Legacy of the Northwoods, 910 Winter St., Eagle River, WI 54521.