(CNN) The final moments of EgyptAir Flight 804 are as perplexing as they are disturbing.
The plane, carrying 66 people from Paris to Cairo, disappeared from radar over the Mediterranean Sea early Thursday morning.
Here's what happened (all times are for Paris/Cairo, which share the same time zone):
11:09 p.m. Wednesday (5:09 p.m. ET Wednesday) -- Flight 804 takes off from Paris' Charles de Gaulle Airport. It's supposed to arrive in Cairo about four hours later, at 3:15 a.m. Thursday.
1:24 a.m. Thursday (7:24 p.m. ET Wednesday) -- The Airbus A320 enters Greek airspace. Athens air traffic control authorizes the plane to continue its course.
1:48 a.m. -- Still in Greek airspace, the plane checks in at the next control point -- Key Island, south of Athens. The pilot was cheerful and thanked the air traffic controllers, the Hellenic (Greek) Civil Aviation Authority said.
2:27 a.m. -- Athens air traffic control tries to contact the pilots to transfer communications control from Greece to Egypt. Despite repeated calls, the pilots did not respond.
2:29 a.m. -- At about the same time the aircraft leaves Greek airspace, its signal drops from radar 13 kilometers (8 miles) south-southeast of KUMBI, an aviation reporting point in the Mediterranean Sea. Immediately afterward, the Greek Air Force was summoned for possible radar target tracking. But the plane has not been found.
2:45 a.m. -- Search-and-rescue operations begin, according to Greek officials.