Back a few weeks ago, on the 24th of March, 2006 over the mid Atlantic one of Airbus's A380 Test aircraft crashed into the ocean killing all 28 people on board the aircraft. It was on a test flight from the secret hanger at an airport neat Toulouse, France up around the North Pole and back. Soon after looping around the North Pole the planes control systems began to get stiff. The rudder, flaps and ailerons were still moving, albeit slowly, they radioed back to headquarters, who informed them to continue the flight, but to turn on the cabin heaters. It was thought that this would warm up the hydraulic tubes. Everything was satisfactory for the next 3.5 hours.
|
We were able to recover the cockpit voice recorder and the flight data recorder. Using this invaluable information, here is what we believe happened. The heaters made the hydraulic fluids heat up to much causing the fluid to turn into a gas. The pilots then ordered assistant flight maintenance engineer Alexandre Mattia to shut off the heaters in an attempt to cool the fluid back to a liquid temperature. Instead of gradually turning down the heaters, it was cold down there in the belly of the aircraft, so he just turned them off, and came back up. The protocol Airbus set out for heating and cooling of the hydraulics system is as follows. "In order to prevent catastrophic failure of the hydraulics system, you must gradually heat and gradually cool the hydraulics system, if you do not the fluid may freeze or boil and expand or contract the metal, which can lead to premature failure of the system." It is clear to see that this in fact happened, the rapid cooling caused the metal to contract, somewhat weakening it, while at the same time the hydraulic fluid being a water based substance, expanded, thus causing a rupture of the tube in multiple places.
|
The plane suddenly banked 50 degrees to the left, tilted to a pitch of 16 degrees downward, and the rudder yawed in the opposite direction. The pilot tried to correct my pulling the wheel up and to the right this opposing force was enough to sheer the left wing off. This massive shift in weight caused the plane to then bank to the opposite side. It was now corkscrewing clockwise while heading downwards at an angle of 30 degrees to begin with, increasing at an angle of 2 degrees a second initially, then 3 degrees, then 5 degrees until it stopped changing about 15000 feet before it hit the water at an angle of 73 degrees. This massive weight shift also put renewed stresses on the rudder, and vertical stabilizer, which consequently ripped off soon after the wing did, within 2 seconds. Below you will see an artists photo realistic rendering of what we believe happened, as you can see the failure was near the front under the nose cone. But this caused all of the fluid to then be sucked out by the vacuum of the upper atmosphere of which it was flying in and, the increased speed, of 600 kias (Knots of Inidcated Air Speed).
|
