Apologising in court for his actions, Franz Strambach said that he had not meant to spread fear or to crash the light aircraft into a skyscraper, but to ditch it into the Main river.

"I wanted the world to know that I was putting an end to my earthly life in order to go to Judith," he explained.

During the January 5 drama, as his plane seemed to hover menacingly around Frankfurt's skyscrapers, the psychology student said in a television interview that he wanted to honour Judith Resnik, who died in the 1986 Challenger space shuttle disaster.

Prosecutors have asked that Strambach be placed into permanent psychiatric care, saying he remains a danger to the public.

They claim a "critical development of his mental disturbance" rendered him criminally unaware of his actions.

A verdict may come later Friday.

Strambach, 32, who has been in psychiatric care since his arrest, told the court that he had felt persecuted by various intelligence agencies because of his love for Resnik.

His sense of persecution left him for weeks unable to sleep longer than an hour a night and, confused and desperate, he decided that the only way out was suicide.

"I now know that I was very sick and completely divorced from reality," he said, adding however that medication had helped him recover.

After a 10-minute address to the judges, he asked the court "to help me on my future life path."

Strambach stole the plane at Babenhausen, a small suburban airfield, after forcing out its two occupants. He was armed with a handgun that fires blanks, similar to a starter's pistol and generally considered not lethal.

During the incident, all air traffic at Frankfurt airport, Germany's busiest, was halted, local transport restricted and parts of the city centre sealed off.

The case, notably in light of the September 11, 2001 attacks in the United States when hijackers ploughed passenger planes into the World Trade Center in New York and the Pentagon outside Washington, prompted Germany to rethink its air security laws.

Earlier this week, the centre-left government agreed that planes that have been hijacked by terrorists in its airspace can be shot down as a last resort to avert a major disaster.

SPACE.WIRE