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Flight 214 Crash

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posted on Jul, 9 2013 @ 11:33 PM
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So I remember reading this article about Tampa airport having to redo the numbering on the runway lanes because geomagnetic north had changed.

phys.org...

I was reading this article about Flight 214



news.yahoo.com...

"The pilots of Asiana Flight 214 that crashed at San Francisco airport have told investigators they were relying on automated cockpit equipment to control their speed, turning a focus of the accident investigation toward whether a mistake was made setting the autothrottle or if it malfunctioned.

One of the most puzzling aspects of the crash Saturday has been why the wide-body jet came in far too low and slow, clipping its landing gear and then its tail on a rocky seawall just short the runway."


Is it possible that the autopilot feature could have been confused to recent changes to geomagnetic north, and as computers can sometimes do, mess up? I guess the question that I don't know the answer to is: Does the equipment in a plane that uses autopilot / flyby wire technology, does it utilize geomagnetic north as a constant reference? I'm guessing it would.

I'm sure it's probably just faulty equipment or operator error, but what if it wasn't...
edit on 10-7-2013 by Gemwolf because: Added ex tags




posted on Jul, 10 2013 @ 01:08 AM
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Originally posted by ColdGalaxy
"The pilots of Asiana Flight 214 that crashed at San Francisco airport have told investigators they were relying on automated cockpit equipment to control their speed, turning a focus of the accident investigation toward whether a mistake was made setting the autothrottle or if it malfunctioned.


Why would the plane's autopilot reduce speed unless the radar altimeter was malfunctioning to reduce altitude thinking it was higher than it was?

Do they cross check with barometric altimeters?



posted on Aug, 22 2013 @ 11:02 PM
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Originally posted by Miracula

Originally posted by ColdGalaxy
"The pilots of Asiana Flight 214 that crashed at San Francisco airport have told investigators they were relying on automated cockpit equipment to control their speed, turning a focus of the accident investigation toward whether a mistake was made setting the autothrottle or if it malfunctioned.


Why would the plane's autopilot reduce speed unless the radar altimeter was malfunctioning to reduce altitude thinking it was higher than it was?

Do they cross check with barometric altimeters?


Autothrottle Rollback

The autopilot uses data from radio altimeters, not from barometric altimeters.

The US FAA reported that the Asiana aircraft experienced several shifts of mode on the autothrottle on final descent and it does not seem logical to me that the pilots would be manipulating these mode changes....

That causes me to suspect there was a system malfunction.

I do not mean that the system was unserviceable, rather that there may have been electronic interference disrupting the system.

I am not an expert on aircraft systems but I have had a few hours flying a 737NG. I stand to be corrected but i believe the autothrottle gets a cue to retard throttles as altitude reaches minimums. Autothrottles have a display into which you input the desired speed and then after that whether you put the nose up or down the system then reduces or increases power to maintain the same airspeed.

In another mode it can also be set to hold a certain preselected altitude but this was not the mode it should have used at the time of the crash.

Pilots preselect the mode and either the speed or the altitude as required then the system is left alone. On approach one would not be constantly fiddling with the selector to make changes. One chooses the speed and mode before descent to land and usually would leave it alone after that.

When the autothrottle retards without pilots commanding it, that is called autothrottle rollback. That is a serious problem which ahs apparently caused several crashes or incidents and may be the real explanation behind Egyptair Flight 990's crazy dive into the sea where the co-pilot was blamed.

It certainly was the cause for Turkish Airlines Flight 1959 in 2009 at Schipol, Amsterdam.

What is more relevant to ask about the altimeter is could lap top devices or cell phones inside the cabin have caused interference with the radio altimeters?

In my view radio interference may have caused a rogue signal which rolled back the throttles prematurely.

A signal might have originated from outside the aircraft perhaps from a powerful radar, but that is less likely because the aircraft's cabin forms a Faraday cage to prevent outside interference.

In June 1995 a Dash 8 from Ansett New Zealand collided with the ground after the radio altimeter hung up during an instrument approach. The Captain reported the radio altimeter sudenly flipped a thousand feet as he watched it and at precisely the same moment the GPWS sounded a 4.5 second warning prior to impact when in fact it should have given about 20 seconds warning.

It later emerged a passenger inside the aircraft used her cell phone to call the airline call centre and complain about the late arrival of the aircraft. New Zealand Police refused to investigate this phone call and crash investigators ignored the issue entirely.

It is a tragedy that people like the Police and crash investigators in this New Zealand case deliberately ignored a possible cause which might years later have taught lessons to prevent another accident however the crash investigation scene is full of egocentric prima donnas.





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