Air France Flight 447 vanished in a zone of ferocious weather over the Atlantic Ocean known as the birthplace of some of the world's strongest storms - just as the plane was encountering a 400-mile-long maze of lightning, hail, driving rain, and 100-m.p.h. updrafts.
So why didn't the pilot simply turn around, avoid the storms, or divert to another airstrip, standard procedure for avoiding severe weather anywhere in the world? After all, no pilot willingly flies directly into a large thunderstorm.
The plane's crew may have tried to navigate through the storms using onboard radar, threading through holes in the weather, but then found itself trapped, unable to get around or over the clouds that towered up to 50,000 feet, experts said.
Joe Mazzone, a retired Delta Air Lines pilot, said that captains often look to their radar at night to weave through thunderstorms, which appear as red blotches, but that in such a volatile region, storms can converge suddenly around you.
"You're penetrating where you think you've got a hole," he said, "and you get in there, and you basically now see that it's red all around you, so you're committed now." At that point, he said, even if the plane were to turn around, it would have to go back through the same weather, presenting a dicey situation both ahead and behind.
And no pilot, Mazzone said, is going to try to simply keep on schedule in dangerous weather at the potential expense of passengers' lives.
A Brazilian Air Force spokesman has said the plane's debris field in the ocean may suggest the pilot did indeed try to return, because parts of the plane were found just outside the flight's path, near where the last signal was emitted before it disappeared. Searchers found debris in a region known as the Intertropical Convergence Zone, a nearly continuous band of colliding weather systems near the equator.
It's where winds from the Northern and Southern Hemispheres clash, spawning violent thunderstorms that can tower 60,000 feet, far higher than any commercial airliner could fly over.
Weather reports from the time indicate massive thunderstorms were developing over a 400-mile-long route directly along the flight's path Sunday night. Basically, this zone, which experts refer to as the ITCZ, is a stormy weather band that wraps some 25,000 miles around the world, generally hugging the equator.
While the region can be quiet and calm, it is also "the birthplace of our strongest storms on Earth," said Henry Margusity, a senior meteorologist for AccuWeather.com. The convergence of weather from opposite hemispheres fuels the production of thousands of small storms that can merge to form massive ones, sometimes in continuous bands, like what apparently happened Sunday.
Brazilian officials said the plane's last electronic message came at 10:14 p.m. EDT, indicating loss of air pressure and electrical failure. AccuWeather showed towering thunderheads were sending updrafts of up to 100 m.p.h. into the jet's flight path at that time.
Mazzone said that if the Air France pilot found himself trapped in these storms, it could have been catastrophic, with updrafts sucking the plane up and down, while being battered by huge hail.
Still, a plane crash caused solely by a storm in this volatile weather zone is rare, said Larry Burch, deputy director of the Aviation Weather Center. Thousands of flights every year travel across this stormy equatorial region worldwide without incident. "It's something that's done every day," Burch said. "What happened Sunday night, though, I just can't say."