Flight 8501’s request for new path was denied

Surrounding airspace was crowded and aircraft had to remain at low altitude

The plane sought permission to climb above threatening clouds. Air traffic control couldn’t say yes immediately there was no room. Six other commercial airliners were crowding the surrounding airspace, forcing AirAsia Flight 8501 to remain at a lower altitude.

Minutes later, the jet carrying 162 people was gone from the radar. No distress signal was issued. It is believed to have crashed into Indonesia’s Java Sea on Sunday morning, but exactly what happened and whether the plane’s flight path played any role won’t be determined until after the aircraft is found.

The last communication from the cockpit to air traffic control was a request by one of the pilots to increase altitude from 32,000 feet to 38,000 feet because of the rough weather. The tower was not able to immediately comply because of the other planes, said Bambang Tjahjono, director of the state-owned company in charge of air-traffic control.

The twin-engine, single-aisle plane was last seen on radar four minutes after the final communication from the cockpit.

Search and rescue crews were looking for the plane with at least 15 ships, seven aircraft and four helicopters, national search and rescue spokesman Jusuf Latif said. The disappearance and suspected crash caps an astonishingly tragic year for air travel in Southeast Asia, and Malaysia in particular. Malaysia-based AirAsia’s loss comes on top of the still-unexplained disappearance of Malaysia Airlines Flight 370 in March with 239 people aboard, and the downing of Malaysia Airlines Flight 17 in July over Ukraine, which killed all 298 passengers and crew.

“Until today, we have never lost a life,” AirAsia group CEO Tony Fernandes, who founded the low-cost carrier in 2001, told reporters in Jakarta airport.