Pensioner twins Frank and Ralph Land will be jumping out of a plane at 8,000ft on 1st April to raise money for some of the world's poorest people.
The plucky duo will be joined on their dive by four of Frank's grandchildren, Izzy Burr, 28, Emma Place, 22, Adam Place, 26, and Chloe Place, 24.
The jump will take place at 10am on April 1 at Dunkeswell Airfield, in Devon.
Funds raised from the feat will go towards the development work of Christian Aid.
Ralph, from London, is doing the dive in memory of his wife Jacqueline, who died of pancreatic cancer three years ago, and in celebration of Frank's 60th wedding anniversary.
Reflecting on the last six decades with wife Ailsa, Frank, of Totnes said: "In our 60 years together we have brought up a family and have completed fulfilling careers in industry and academia. But in that time we have seen much misery worldwide, particularly in the less developed world.
"Our diamond jubilee brings our family and some good friends together, and provides an opportunity for all of us to make some contribution to the lives of others less fortunate then ourselves.
"Christian Aid's initiative in organising the sky dive in the middle of our celebrations was too good an opportunity to miss.
"I tried to convince my children to take part, but they refused. However, my grandchildren agreed to do it instead, so it will be the oldies and the young'uns."
In addition to Christian Aid, Ralph's dive is also supporting Cancer Research UK.
He said: "Half the proceeds of my skydive will go to Christian Aid to support a number of vital international projects, to aid some of the millions of vulnerable people caught up in war zones, natural disasters and poverty.
"The other half will go to Cancer Research UK, specifically to seek treatment for a devastating cancer with, currently, very low survival rates."