Image copyright AP Image caption The gyrocopter was inspected by bomb squad members after it landed

A Florida man could face up to nine years in prison after he flew a gyrocopter into Washington's restricted airspace and landed at the US Capitol.

Douglas Hughes, 61, was indicted on six charges on Wednesday including violating national defence airspace.

Mr Hughes has said the flight, which occurred last month, was intended to draw attention to the influence of big money in politics.

The stunt has spurred congressional hearings about airspace safety.

Mr Hughes took off from Gettysburg, Pennsylvania, on 15 April. He was arrested as he landed on the Capitol building's west lawn.

"We are looking at a case where there was no injury and no property damage, and the requirements as far as what the prosecution is asking for include years of jail time," he told the Associated Press on Wednesday.

Image copyright AP Image caption Mr Hughes was captured on camera in March flying his gyrocopter in Florida

"The penalties that they are demanding are not consistent with the damage,'' he added.

Mr Hughes faces charges of operating as an airman without an airman's certificate and violating aircraft registration requirements, which each carry terms of up to three years in prison.

Three misdemeanour charges of violating national defence airspace have also been brought against him. They carry a maximum jail term of of one year.

Mr Hughes has been placed on home detention and has not been allowed to return to Washington or operate any aircraft.

However, he will be permitted back in Washington on Thursday for a federal court appearance.