Preliminar do acidente da Helios Airways Flight 52

[Anonymous]

Accident Investigation Summary (As of 7 September 2005)
The investigation of the crash of the Helios Airways Flight 522 has confirmed that the pressurization system on the plane was not activated because the pressurization valve and an air outflow valve were set incorrectly. Thus, the airliner cabin failed to pressurize on take-off. The investigation has further reportedly shown a basis for asserting claims not only against Helios Airways but also Boeing Corporation, the manufacturer of the plane. Crew members were apparently confused as to the meaning of a warning horn and failed to recognize that the cabin was not pressurizing until they grew mentally disoriented because of lack of oxygen and lost consciousness.
The Helios plane, a Boeing 737-300, underwent maintenance the night before the accident. The maintenance crew report left a pressurization controller rotary knob out of place, which meant that the plane could not pressurize properly. At 10,000 feet, an alarm went off to warn the crew that the plane would not pressurize. Crew members mistakenly thought that the alarm horn was a warning to tell them that their controls were not set properly for takeoff.
In the Boeing 737, the same horn is used for both failure of pressurization and failure to set controls properly for takeoff, although it will sound for takeoff configuration only while the plane is still on the ground.
The plane continued to climb on autopilot. At 14,000 feet, oxygen masks deployed as designed, and a master caution light illuminated in the cockpit. Another alarm sounded at about the same time on an unrelated matter, warning that there was insufficient cooling air in the compartment housing avionics equipment.
As the plane continued to climb on autopilot, the air grew so thin that the crew became seriously impaired. The captain lost consciousness first on the floor of the cockpit, followed by the co-pilot, who remained in his seat, according to the officials. The autopilot took the plane to 34,000 feet to Athens, entered a holding pattern, until fuel ran low and one engine quit.
Boeing, the maker of the plane, issued a notice shortly after the crash to airlines that it would revise flight crew training manuals to emphasize to crews that they must understand how the various warning systems work and what to do about them. "Confusion between the cabin altitude warning horn and the takeoff configuration warning horn can be resolved if the crew remembers that the takeoff configuration warning horn is only armed when the airplane is on the ground," the notice said. "If this horn is activated in flight, it indicates that the cabin altitude has reached 10,000 feet."

[DanielVS]

Parece que o texto foi extraído do site de uma firma de advocacia.

http://www.globalaviationlaw.com/accident-helios.htm