Week 4

I am having a hard time trying to incorporate this weeks chapter with my topic (Aircraft Fire and Hypoxia) so instead, I will be adding more information about hypoxia to this page.

Helios Flight 522
August 14th, 2005
121 Fatalities

This flight was the most devastating accident to ever happen in the aviation history of Greece. Helios Airways was a cheaper airline that was popular among the people of Greece because of the lower airfare.

This accident was determined to have been caused by a loss of pressurization in the aircraft. They determined that after maintenance personnel had performed a pressurization check before the flight. Once completed, they did not turn the pressurization switch back to auto but didn't. Both the Co-Pilot and Pilot did not notice that this switch was in the manual position when they were doing their checks prior to flight. Because of this, The aircraft was never pressurized for flight at the altitude they had flown, which was 32,000 ft. Supplemental oxygen should be used at altitudes above 12,000 ft.

ATC lost contact with the crew within 30 minutes of flight, which was during their climb to 32,000 ft. Crew and passengers were unconscious in the aircraft before impact, they had been flying for about 3 hours before they began to run out of fuel, this flight was scheduled to originally be 1.5 hours. There were no survivors.

Because this crew continued to ascend, the effects of hypoxia worsened. They surely lost consciousness as well as the passengers early on as useful consciousness at 30,000 ft is about 1-2 minutes.

Pilot's Handbook of Aeronautical Knowledge Chapter 15 - American Flyers. (n.d.). Retrieved September 5, 2014.

The effects of hypoxia vary between every pilot and how long they have been at a certain altitude. So to play it safe, you should always follow the FAR.

According to the FAR Part 135 sec 135.89;

"(a) Unpressurized aircraft. Each pilot of an unpressurized aircraft shall use oxygen continuously when flying—
(1) At altitudes above 10,000 feet through 12,000 feet MSL for that part of the flight at those altitudes that is of more than 30 minutes duration; and
(2) Above 12,000 feet MSL. "