January 1, 1970 · FLEMING | NOLEN | JEZ, L.L.P.
The Australian Transport Safety Bureau (ATSB) recently releasedMH370 – Definition of Underwater Search Areas. In its report, the ATSB limited the new potential search area by modeling the flight patterns of different accident types and the most likely end points for each type. The ATSB found Flight 370 most closely matched the “hypoxic crew” pattern.
The ATSB looked at several plane crashes caused by a hypoxic crew, including the 1999 Learjet crash involving golfer, Payne Stewart, the 2005 Helios Airways crash, and the 2000 Beechcraft Super King Air crash in Queensland. A crash from 1980, involving athlete and coach, Bo Rein, was not evaluated, but displays the same pattern as the other hypoxic crew accidents.
Hypoxic crew accidents generally begin with loss of radio communications. The plane then maintains a steady course and altitude for a long period of time without any typical aircraft maneuvering. Eventually, fuel is exhausted and the plane begins to descend. Control is lost when the engines finally shut down.
Accidents Caused By “Hypoxic Crews”
The Payne Stewart and Bo Rein Crashes
The Payne Stewart flight left Florida and the plane began its climb to the planned cruising altitude. Sometime during the ascent, the pilot stopped communicating with air traffic controllers. The plane continued on its altitude and course without making the western turn to its destination in Dallas. The plane was intercepted and monitored by nearby Air Force planes. No movement was spotted inside the plane and the windows appeared covered with condensation. Eventually, the engines burned out when fuel was exhausted and the plane crashed down in South Dakota.
The Bo Rein crash followed an almost identical pattern, though the communications with the pilot ended after the plane re-routed to avoid a storm and began climbing. The official investigation of the Payne Stewart and Bo Rein crashes suggested the most likely cause was a hypoxic crew because of cabin depressurization.
The Helios and Queensland Crashes
The Helios crash began with normal plane operations. As the plane began to ascend, strange communications with the crew concerned air traffic controllers. The pilots were not properly answering questions regarding an in-cabin alarm, and they eventually stopped communicating altogether. The plane continued over the Mediterranean Sea at the planned cruising altitude until auto-pilot put the plane into a holding pattern near the planned destination. Air Force planes sent to monitor the flight reported the oxygen masks were dangling, the pilot could not be seen, and the co-pilot appeared slumped over in his chair. Eventually, the engines burned out and the plane crashed down in the nearby hills.
The Queensland crash closely resembled the Helios accident, although there was no aural alarm and air traffic could still hear open mike transmissions after the pilots stopped communicating. Official investigations of the Helios and Queensland crashes stated hypoxia from depressurization caused incapacitation of the crew and led to each crash.
Missing Malaysia Airlines Flight 370
Like the accidents evaluated by ATSB, Malaysia Flight 370 began with a normal ascent to cruising altitude. Soon, air traffic control lost communications with the pilot and heard only static in response to questions. While every other crashed plane evaluated had been intercepted and monitored during the cruising phase, the path of Flight 370 was only monitored by satellite before it finally disappeared. Satellite data indicates the plane was following a steady course over the Indian Ocean when it was lost. The plane likely would have crashed down wherever the fuel was finally exhausted.
The ATSB selected the hypoxic crew event type as a best fit for Flight 370 because: (1) the flight began normally; (2) communications were inexplicably lost; and (3) the last data on Flight 370 shows it was following a steady course out toward the projected search area. Using the hypoxic crew model, the ATSB was able to prioritize a new search area. The area is still being mapped out and search efforts are expected to begin this fall. Grieving families are still waiting for answers and hopefully the new search area will provide them.