An animal rights enthusiast who piloted a gyrocopter which killed a Warwickshire Hunt supporter believed he had been shot at from the ground and feared a "gang" was on its way to attack him, a court heard.
Bryan Griffiths, 55, is charged with the manslaughter by gross negligence of Warwickshire Hunt member Trevor Morse at Long Marston airfield on March 9 last year.
Jurors at Birmingham Crown Court heard Mr Morse's head was cleaved "from top to bottom" by the blade of the gyrocopter as he tried to stop it from taking off.
Mr Morse, 48, refused to move out of the way as Griffiths went towards him and the aircraft's rear propeller, moving at a speed approaching 200mph, cut his head from top to bottom, killing him instantly, the court heard.
Griffiths had been monitoring the hunt from the air and had stopped to refuel.
Michael Tipping, who describes himself as an "aviation fanatic", was at the scene of the stand-off and had chatted to Griffiths about his gyrocopter before Mr Morse arrived at the airfield, near Stratford-upon-Avon.
He told the court that when Mr Morse arrived in his blue Land Rover, which he parked at the nose of the gyrocopter, and began taking pictures, his manner was "intrusive and aggressive".
He said: "When I spoke to him asking what he took pictures of my car for, my mind said to me, 'you don't want to mess with this man'."
Asked by James Wood QC, defending, if he felt threatened by Mr Morse, he said, "Yes I did, particularly if I'd have argued with him, yes. Which is why I didn't argue with him."
Mr Tipping said Griffiths had asked him to stay at the scene because he feared trouble was imminent. In a statement read to the court, Mr Tipping told police: "I thought, 'oh crikey, don't say this is blinking drugs'.
"He (Griffiths) said I think he (Mr Morse) is trying to hold me up you know, because I think there's a gang coming for me to beat me up.
"He said that he believed that he had been shot at three times while he was flying the autogyro."
Jurors, who viewed an edited video of the confrontation, heard that Mr Morse, a road monitor with the hunt, and one of the hunt masters had a "plan" to stop the gyrocopter from taking off when it stopped to refuel.
Anthony Spencer, one of the hunt's six masters, said they had agreed to "pin it in" and keep it on the ground so that they could take photographs of the pilot.
The incident was caught on camera by the man who had brought fuel to the airfield, Peter Bunce.
Griffiths, of Wiltshire Close, Bedworth, north Warwickshire, denies manslaughter by gross negligence.