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My top priority
He who will never leave and never dies.
We don't have to work to impress God.
He knows who we are and accepts us with unconditional love.

Tuesday, June 9, 2009

AF447


I cannot sit still until I know what happened on the AF447. I usually don't display such interest in world news but this involves aviation and lives that perished in such a state it's inconceivable.

I cannot fathom as to why a technology so equipped as the Airbus330 could meet its final end in such a compellingly devastating manner. I mean, it's a relatively safe plane. We have many fleets of this model in the world.Perhaps in studying how, why and what, lives can be saved in the future.

We have to understand that this state of the art aircraft is operated fly-by-wire. This simply means computerized.The pilot's controls are not directly connected to the aircraft controls. It actually just sends a signal to the computer, and the computers on board actually drive the flight controls.There are four fully redundant electrical systems on an Airbus - and if the worst happens a manual flight control system allows the crew to manipulate the rudder and the fine aero-surface controls called trim tabs.

I have no idea until I came across an article on this in CNN.com.

We know Flight 447 struggled to fend off violent thunderstorms in the Intertropical Convergence Zone. It's essentially where the North Atlantic meets South Atlantic off the coast of Brazil.
This is the danger zone where the trade winds from the Northern Hemisphere and Southern Hemisphere meet. It spawns rare hell-raising thunderstorms( I kid you not) and severe turbulences. Hurricanes make things worse if encountered. It was believed this aircraft was struck by lightning, maybe even several.Some probably got into the system, messing up the computers one by one and disabling radar.The crew was thrown the obstacle of trying to manage in the dark, over the ocean and without weather radar as they stumbled towards some epic cumulus nimbus thunderheads.But the whole point is, can only lightning bring this aeroplane down? Planes are designed to withstand lightning strikes.Thus, this means there might have been a cascade of events starting from a voltage surge provoking massive electrical failure.

The Brazilian air force says the plane was traveling at an altitude of 35,000 feet at the speed of 521 miles per hour when it simply vanished from radar. So is this travelling speed safe or dangerous? I need an airline safety analyst expert to explain all these, sincerely, as I have no clue.One thing for sure, there was not even a distress call from the aeroplane itself, bringing possibility that the whole incident was utterly quick.

Then a recent probe reveals that the airspeed instruments have not been replaced on the AF447.

In addition to that,the investigation is increasingly focused on whether external instruments may have iced over, confusing speed sensors and leading computers to set the plane's speed too fast or slow -- a potentially deadly mistake in severe turbulence.

Pitot tubes, protruding from the wing or fuselage of a plane, feed airspeed sensors and are heated to prevent icing. A blocked or malfunctioning Pitot tube could cause an airspeed sensor to work incorrectly and cause the computer controlling the plane to accelerate or decelerate in a potentially dangerous fashion.

Gathering all these seem to be telling a story of the whole system malfunctioning at once.Indeed very grave.

As quoted from the New York Post,the sequence of the crash,

At 11pm (2am GMT) pilot Marc Dubois sent a manual signal saying he was flying through an area of 'CBs' - black, electrically charged cumulonimbus clouds that carry violent winds and lightning.

At 11.10pm, automatic messages relayed by the jetliner indicated the autopilot had disengaged.
This suggested Dubois and his two co-pilots were trying to thread their way through the storm manually.
At this point a key computer system had switched to alternative power and controls needed to keep the plane stable had been damaged.
An alarm also sounded, indicating that the 'fly-by-wire' system on the Airbus that controls the flaps on the wings had shifted to 'alternate law'.
Alternate law is an emergency back-up system that kicks in after an electronic failure. It enables the plane to keep functioning with less energy - but reduces stability, which would have been desperately needed as the pilots battled to bring the jet safely out of the turbulence.

At 11.12pm, two key computers monitoring air speed, altitude and direction failed. These would have increased the pilot's loss of control over the plane.
The loss of instruments showing air speed in particular would have been detrimental. The pilot was trying to fly a fine line between slowing the plane enough to navigate through the turbulence, and not slowing so much that the plane stalled mid-air, which would have been catastrophic.
The messages show there was an inconsistency between the different measured airspeeds shortly after the plane entered the storm zone.

At 11.13pm, control of the main flight computer, back up system and wing spoilers also failed.
The last automatic message, at 11.14pm, indicated complete electrical failure and a massive loss of cabin pressure - catastrophic events

There are still no clear answers but with the latest developments in the extrication of some of the bodies and plane debris,it is a small consolation that the families get to bury their beloved.

2 comments:

Sophia said...

sudden bout of inspirations again eh

Taffy A.E. Jong said...

yalor but then it's on a tragedy. sigh.I still can't believe it actually happened but it did.