Questions about air tragedy that leave the world wondering
NEW YORK— As rescuers search Indonesian waters for AirAsia Flight 8501, missing with 162 aboard, the world asks what led up to this tragedy.
1. What could have happened?
It is too early to know for sure but here are some options. The plane was in the safest part of flight: just 10 per cent of fatal crashes from 2004 through 2013 occurred while a plane was at cruise elevation.
Passing through bad weather such as severe thunderstorms could be a factor. Airbus jets have sophisticated computers that automatically adjust to wind shears or other disruptions. But weather, combined with pilot errors, has played a role in past air disasters that occurred at cruise elevation, including the 2009 Air France crash over the Atlantic Ocean.
Another possibility is some type of catastrophic metal fatigue caused by the cycle of pressurization and depressurization associated with each takeoff and landing cycle.
2. What did the pilots say to air traffic controllers?
Their last communication was at 6:12 a.m. Sunday when the pilot “asked to avoid clouds” by turning left and ascending to 38,000 feet. The last radar contact was three minutes later. There was no distress call. Keep in mind, pilots are trained to focus on the emergency and then to communicate only when free.
3. How far could the jet fly?
Looking at the flight’s paperwork, the plane had more than 18,000 pounds of jet fuel at takeoff, enough to fly about 31⁄ hours, according to Phil
2 Derner, founder of aviation enthusiast website NYCAviation.com.
4. Is the Airbus A320 a safe jet?
The plane is a workhorse of modern aviation. Similar to the Boeing 737, the twin-engine jet is used to connect cities that are between one and five hours apart. Worldwide, 3,606 A320s are in operation. The A320 family has a good safety record, with just 0.14 fatal accidents per million takeoffs, according to a Boeing safety study.
5. What about AirAsia?
Low-cost AirAsia has a strong presence in most of Southeast Asia and recently expanded into India. None of its subsidiaries has lost a plane before, and it has a good safety record. But it does fly in a region where air travel has expanded faster than the number of qualified pilots, mechanics and air traffic controllers.
6. How does a plane fall off radar?
It’s still unclear what traffic controllers saw on their screens when the jet disappeared from radar. It could be they lost the secondary radar target, created by the jet’s transponder, or the primary radar target, created by energy reflected from the plane. If a plane comes apart in the air or suffers a loss of electrical power, the secondary target is lost, but the primary target is often still visible on radar.
But if it falls at a rate of over 2,000 metres a minute — typical of a plane about to crash — the primary target might be lost as well.