Lindsay Deutsch
USA TODAY
March 7, 2015

Three commercial plane crashes and recoveries dominated the news last year. Malaysia Airlines Flight 17 was shot down in eastern Ukraine. AirAsia Flight 8501 crashed into the Java Sea during bad weather. And Malaysia Airlines Flight 370 — well, what happened in the skies with that jet remains shrouded in mystery.

Officials are still searching a vast area for any sign of MH370 one year after the crash on March 8, 2014. So what makes Flight 370’s case so different from Flight 8501, which was on a similar flight path?

Several factors contributed to why the debris from the AirAsia plane was located, rather than remaining the subject of conspiracy theories:

1. The AirAsia debris field was in relatively shallow water. Debris from the AirAsia jet was found in Indonesian waters — including the Karimata Strait between Sumatra, Java and Borneo, a large island shared among Indonesia, Malaysia and Brunei — at a depth of about 150 feet.

The location of Malaysia Air Flight 370, however, is unclear. The search that started in the South China Sea spanned out to the Indian Ocean and beyond. Pings thought to possibly be from the plane’s black box provided a false lead in April. Searching continues in parts of the Indian Ocean that have crevasses and dips that go as deep as 4 miles.

2. Weather difficulties provided information. Before it lost contact with air-traffic control, AirAsia Flight 8501 had asked for permission to climb to a higher altitude to avoid tropical storm clouds. Other aircraft were in the area, so controllers temporarily denied the request.

Before Malaysia Airlines Flight 370 disappeared, all seemed smooth on the horizon, keeping its downfall a complete mystery. “All right, good night,” was reported to be the pilot’s final message to air-traffic control before it lost contact.

3. Tracking was working. Not only was AirAsia flying in more populated skies over relatively shallow water, but the flight did not deviate from its flight plan, and communications were working correctly until contact was lost.

Flight 370 flew for hours after it lost ground communication and was well off course.

4. Size of search area. Search for the AirAsia flight focused on a 70-square-nautical-mile area between Belitung island, off Sumatra and Borneo island.

The Malaysia Airlines Flight 370 search area was more than 100,579 square miles and covered parts deep in the southern Indian Ocean. About 10,000 square miles have been scoured, and the goal is to search 23,000 miles by May.