He just wanted to prove that he could do it..Why dont you come Visit it here (about 40 miles from my house) at...
http://www.sprucegoose.org/Howard Hughes did want to prove he could do it. However, he also didn't fly it again because he never regained his former courage after he was badly burned in a test flight he conducted of a military spy plane that he designed. The accident took place a just few years before the Spruce Goose flight.

This is about the time that his obsessive compulsive disorder began to completely take over his life.He actually had a military contract to build a huge troop transporter and something happend after some delays the contract was cancelled and he finished building . He flew it one time to show the military that it could fly,,, Who knows if it could fly higher or longer or what would happen fully loaded ,

But from the info i gathered it was grossley underpowered and he knew that and that may be the only reason he flew just a few feet off the water,,, He was always and aviation nut,,, Did you know howard hughs dated gloria vanderbilt
and would fly her around los angeles?? guess who her only son and heir is,, None other than cnn,s anderson cooper..
You never would suspect the guy is worth millions upon millions before he even got out of high school... He is probably the richest newsman in history.. His mother had gloria vanderbilt jeans, makeup, a movie star, and she was heir to a railroad magnate. im sure on her death he could be worth over 100 million easilyHoward Hughes built the huge transport seaplane under contract from the US Army during World War Two. The war ended before the airplane was completed, and there was lots of bad press about the wasted money and the contract was canceled by the Government.

The airplane was never approved for flight by the US Government, and there were many politicians, bureaucrats and "experts" who said it could not fly, and accused Hughes of ripping off the Government. Hughes took it out for a "High-Speed Taxi Test" and lifted it off the water just to prove that it could be done.the power from the engines was not sufficient to make the plane gain and maintain altitude the weight of the plane was very much the contributing factor which caused this.give it modern day jet engine and it might fly'