Washington: A Federal Bureau of Investigation (FBI) affidavit has claimed that a cyber-security consultant who was pulled off a flight in April this year for sending tweets about hacking into a plane's controls admitted to temporarily taking control of an airplane and causing it to fly sideways. US authorities are investigating the man's claims.

In April, Chris Roberts was detained by the FBI following a United Airlines flight to Syracuse, New York, after officials saw Twitter posts he made discussing hacking into the airplane he was traveling on.

An FBI search warrant application filed in the U.S. District Court for the Northern District of New York describes the investigation of Roberts for possible computer crimes.

During interrogations, Roberts told investigators he hacked into in-flight entertainment systems aboard aircraft and claimed to have done 15 to 20 times from 2011 to 2014.

Roberts also said that once he had hacked into the systems and then overwrote code, enabling him to issue a "CLB," or climb, command.

Roberts knew of vulnerabilities aboard one Airbus model and three types of Boeing aircraft. He hacked into in-flight entertainment systems made by Panasonic and Thales, he told agents.

However, Roberts said on Twitter that he has been advised not to say much, but he has tweeted that his only interest is to improve aircraft security and accused the FBI of mistakenly condensing 5 years of his research into one paragraph.

Roberts said that he used a modified ethernet cable in order to connect his laptop to an electronic box beneath his seat that controls the entertainment system. From there, he hacked into the aircraft's computer nerve center, the document cites Roberts as telling the FBI.

According to federal court documents, on 15th April, United Airlines told the FBI that Roberts had posted tweets about hacking into the airplane he was traveling on and possibly activating the emergency passenger oxygen masks.

The FBI agents tracked the airplane that Roberts traveled on from Denver to Chicago and found evidence of tampering and damage to electronic control boxes that connect to in-flight entertainment systems.

According to FBI search warrant, agents seized computer equipment, including an iPad and a laptop, as well as thumb and external drives.

Roberts said the thumb drives contained "nasty" malware that could be used to compromise computer networks, according to the FBI document.