Andrew, third child of Queen Elizabeth II and Prince Philip, took half an hour to descend from the 87th to the 20th floor of the brand new Shard skyscraper in London to raise money for the Outward Bound Trust and the Royal Marines Charitable Trust Fund.
“I’m not even going to say that was a piece of cake or not,” the 52 year-old prince, who raised more than £290,000 in the stunt, said afterwards. “I will never do it again.”
He then quipped: “I have to say, the most difficult bit was walking up the stairs.”
However Andrew, a former Royal Navy helicopter who served in the Falklands War, admitted later that “the difficult bit was actually stepping out over the edge”.
“You have a moment to realise what you are doing and where you are going to go,” he said.
In preparation for the 785-foot drop, Andrew said he had trained over the summer with the Royal Marines in Arbroath.
That, he said, “gave me the confidence to step out over the edge without too much trepidation”.
Prince Andrew, fourth in line to the throne, officially launched the Shard on July 5 along with Qatari Prime Minister Hamad bin Jassem al-Thani.
The 310-metre (1,017-foot) tall tower, close to London Bridge on the south bank of the River Thames, was inaugurated with a sound and light show.
The £450 million ($700 million, 570 million euro) project, designed like a shard of glass, was 95 percent funded by Qatar.
The Shard’s inauguration marked the completion of the exterior of the building, located on the south bank of the River Thames at London Bridge, while work on the inside is expected to continue into 2013.
The skyscraper, whose name was coined by its Italian architect Renzo Piano, is still significantly shorter than Dubai’s 828-metre Burj Khalifa, the tallest building in the world.
It took over from Capital City Moscow Tower as the highest in Europe.
The building’s futuristic silhouette has angered traditionalists who say it has dwarfed older landmarks such as St Paul’s Cathedral and the Houses of Parliament.
English Heritage, the body responsible for protecting historic sites, says the skyscraper mars a view of St Paul’s, while UNESCO has said it compromises the “visual integrity” of the Tower of London, a World Heritage site.