Chris Roberts, A prominent hacker and security researcher who was kicked off a United Airlines flight last month had previously admitted to the FBI that he had taken control of a plane and made it fly sideways.
If true the discovery opens up a whole new raft of terrifying possibilites for would-be terrorists.
FBI Agent Mike Hurley said: “He stated that he caused one of the airplane engines to climb resulting in a lateral or sideways movement of the plane during one of these flights.
“He also stated that he used software after comprising/exploiting or ‘hacking’ the airplane’s networks.
“He used the software to monitor traffic from the cockpit system.”
The cyber security expert exploited security weaknesses to override the pilots by connecting a cable his laptop and cracking into the default passwords to access the plane’s systems.
According to an FBI affidavit, Mr Roberts hacked the entertainment systems on US flights more than a dozen times between 2011 and 2014.
But Mr Roberts, who is often described as one of the world’s leading experts on cyber security, has defended his actions saying he was trying to make air travel safer.
He recently tweeted: “Over last 5 years my only interest has been to improve aircraft security…given the current situation I’ve been advised against saying much.”
Mr Roberts is said to have gained access to fly by using the Seat Electronic Box, which is installed under passenger seats on some planes.
He removed the cover of the box by “wiggling and squeezing” it off and connecting it to his laptop with an Ethernet cable.
The cyber security expert then used default passwords to access the in-flight entertainment system.
This comes after he was kicked off a United Airlines flight last month for tweeting he might hack into the plane and make the oxygen masks deploy.
Although the FBI are said to have taken his claims seriously, Mr Roberts has not been charged with any crime yet.