The young man had rented the single-motor Cessna and hired the pilot in Augsburg for an air tour around the Bavarian capital on Saturday.
When the plane reached an altitude of some 500 metres above the town of Bergkirchen, the 26-year-old attacked the pilot with a knife. But the pilot managed to fight him off and the man then opted to jump out of the plane, police reported.
The pilot sustained knife wounds to his face and hands, but managed to land the plane back in Augsburg and alert police of the attack.
According to police, the 42-year-old pilot was trained by the Bundeswehr and had flown in the military.
“That certainly helped him in the situation,” a police spokesperson said on Sunday.
The other man's body was found after a woman called to report seeing a figure fall from the sky into a livery building near Palsweis. Doctors determined the man was killed instantly on impact, a police statement said.
Police later found a suicide note in the 26-year-old's apartment. Over the last several years the man had been caught with drugs and committed a few petty offences, Augsburg police confirmed.