Air traffic controllers apparently didn't receive any distress calls.
"There
was nothing abnormal before the plane crash," Egyptian Civil Aviation
Minister Hossam Kamel said Saturday. "It suddenly disappeared from the
radar."
The website Flightradar24, which tracks aircraft around the world, said it had received data from the Russian plane suggesting sharp changes in altitude and a dramatic decrease in ground speed before the signal was lost.
A U.S. satellite that was over Sinai at
the time of the crash detected a heat flash, according to a U.S.
official directly familiar with the latest information in the
investigation. U.S. intelligence and military officials are analyzing
the data to determine whether the flash occurred in midair or on the
ground and what that can tell them about what happened to the plane, the
official said.
Analysts say heat
flashes could be tied to a range of possibilities: a missile firing, a
bomb blast, a malfunctioning engine exploding, a structural problem
causing a fire on the plane or wreckage hitting the ground.
"The
number of heat signatures is crucial," said CNN aviation analyst Miles
O'Brien. "If, in fact, only one was detected, that in some respects
might steer one away from a missile launch and onto some idea of an
explosion onboard the aircraft."
A top Russian aviation official has said the plane broke apart in midair.
Alexander
Smirnov, a Metrojet official, told reporters in Moscow on Monday the
airline had ruled out technical problems and human error. Protection
systems on the plane would have prevented it from crashing, he said,
even if there were major errors in the pilot's control equipment.
The Egyptian military said militants in
Sinai have shoulder-fired, anti-aircraft weapons that shoot only as high
as 14,000 feet, far short of the more than 30,000 feet at which Flight
9268 was flying when it dropped off radar.
Kremlin
spokesman Dimitry Peskov refused to discount terrorism, telling CNN's
Matthew Chance on Monday that "only (the) investigation can rule out
something."
Metrojet executives also
said Monday that it was too early in the investigation to speculate or
draw any conclusions. But Smirnov referred to purported footage of the
crash posted by militants, saying: "Those images you have seen on the
Internet, I think they are fake."