The EgyptAir hijack ended without incident with all passengers freed and the hijacker giving himself up, but officials said the motive behind the act remained unclear.
What initially appeared to be a high-voltage hostage crisis was resolved within hours without anyone getting hurt, but the incident posed serious questions about security at Egyptian airports five months after a Russian aircraft was bombed over the Sinai peninsula.
Officials said the man who forced the Airbus 320 flying between Alexandria and Cairo with 60 passengers and crew to fly to Cyprus had used a fake suicide belt to threaten the pilot.
Airport security footage showed the man, identified as Seif Eldin Mustafa, passing through several security checks at Alexandria's Borg El Arab airport.
Cypriot officials said Mustafa appeared "psychologically unstable" after he made a series of "incoherent" demands.
It was reported earlier that he wanted to meet his Cypriot ex-wife and she was brought to the airport.
Cypriot President Nicos Anastasiades jokingly endorsed this while talking to reporters, saying, "Always there is a woman involved."
"He's not a terrorist, he's an idiot. Terrorists are crazy but they aren't stupid. This guy is," an Egyptian foreign ministry official said, according to the Guardian.
In Cairo, police were questioning Mustafa's relatives after unconfirmed reports said the man had demanded the release of prisoners in Egypt.
The hostage crisis on the Flight MS181 started when the man threatened to blow up the plane if it was not diverted to Larnaca.
EgyptAir said the hijacker released all people onboard except four foreign passengers after landing in Larnaca.
There were eight Britons and 10 Americans among the passengers. Israel scrambled war planes in precaution as the hijack news emerged.