An ill-fated sightseeing adventure has landed five shocked middle-aged Australians in prison in Indonesia's troubled Papua region.

Queensland pilot William Henry Scott-Bloxam, 62, Thursday appeared shocked as he learned he would spend the next three years in prison for flying a small plane into Indonesia without permission.

His four passengers, including his 54-year-old wife Vera; Hubert Hufer, 57; Karen Burke, 51; and Keith Ronald Mortimer, 60, were also told they would spend the next two years in a Papuan prison in an earlier, separate hearing Thursday.

The passengers were fined $2,265, which could be exchanged for an extra two months imprisonment.

The group, from Cape York on the northern tip of Australia, made the one-hour flight from Horn Island on Sept. 12.

They have described it as a sightseeing flight and mistakenly believed they could get visas on arrival in Papua.

"I can't believe this, I will let the lawyers deal with this,'' Vera Scott-Bloxam said after her verdict was handed down in Merauke District Court, in Papua.

She later returned to the court to hear the decision in her husband's case, and was in tears as she and her husband embraced after the sentence was announced.

Merauke District Court chief judge Desbeneri Sinaga said the pilot should have known better, jailing Scott-Bloxam for three years.

"The defendant should have known that you must have a permit to enter another country's air space because the defendant has been a pilot for 40 years,'' Sinaga said.

Scott-Bloxam mistakenly believed authorities had been informed of the planned three-day visit.

"I want the authorities to know that my intention was good but there has been a misunderstanding and lack of information which has caused this incident,'' he said.

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