When Vivien Eyers was deciding on the title of a book about her late brother Geoff Williams, inspiration came from one of her most reliable sources — Mr Williams’ own notes.

A logbook of Mr Williams, a passionate aviator, recounted a time he had flown one of his custom-built aircraft through the Lindis Valley and subsequently crashed it.

‘‘His log just said, ‘rising ground and no room to turn’,’’ Eyers said.

‘‘In other words, it was the ground’s fault, not his fault.’’

Rising Ground; And No Room To Turn tells the story of Mr Williams’ three-decade journey designing, building and flying four aircraft across Otago, none of which were ever certified by the authorities.

Eyers said work on her first book began as a family project six years ago, but expanded as she realised just how much information her brother had left behind after his death in 2002.

‘‘He didn’t hoard material possessions but he hoarded every letter, every piece of paper, everything in his log books, the communication he had with the Civil Aviation Authority (CAA).’’

She believes Mr Williams’ decision not to go down a more orthodox pathway was due to factors that included shortsightedness, but also a determination to experiment with aircraft on his own terms.

‘‘He really wanted to design his own aircraft and build them.’’

Eyers could not fully explain how her brother had managed to test home-made planes for 30 years without ever being seriously injured, but said his patience, creativity and attention to detail probably had a lot to do with it.

As for the law, rumours swirled at the CAA of a mysterious craft in the skies of Otago, yet even when they caught up to Mr Williams their words had little effect.

‘‘He got tracked down and interviewed, then he got sent a few letters, and he got told to dismantle the aircraft. But at that stage the engine had seized anyway, and so it was already not flying.

‘‘And he kind of knew that. He let them send him a few letters before he agreed that he wouldn’t fly it again.

‘‘So he started on Mark III.’’

Eyers said she was not sure whether she would continue writing, but admitted her research also uncovered a lot of information on her late father, a teacher and a Lancaster pilot in World War 2.

‘‘Well, it feels like with all of dad’s resources, there’s a story there. I’ve never tried fiction but I don’t think I can go to fiction. I might stick to the biography stuff.’’

Rising Ground; And No Room To Turn is on sale now.