A student admitted making a hoax phone call claiming there was a bomb on a flight from Gatwick, a court heard.
Muhammet Demir called police and said he had seen a bomb on an easyJet aircraft that was due to fly to Turkey on September 9.
The flight, destined for Izmir, was taxiing on the runway with 170 passengers on board when it was recalled and met by armed police.
Police officers, Gatwick and airline staff, traced the call to 20-year-old Demir who had been due to board the flight.
The call was established as a hoax but it delayed the flight by three hours.
Demir, of no fixed abode, was arrested as he tried to board a flight at Luton airport.
The Turkish national admitted the crime but has refused to say why he made the call.
Demir pleaded guilty to communicating a false message to cause a bomb hoax at Brighton magistrates court on Saturday.
He was remanded in custody and is due to appear before a crown court for sentencing on a date to be set, the Brighton Argus reported.
Detective Inspector Andy Richardson said: “Fortunately we were able to quickly identify that this was a hoax call but it still caused considerable worry for airport and airline staff and passengers.
“Anyone considering making malicious calls of this nature should think long and hard about the consequences.
“We investigate fully all claims and threats like this and will not rest until we find those responsible.
“Making hoax calls not only wastes the time and money of members of the public and the emergency services but also delays us from responding to genuine emergencies.”