Author Topic: *Air France jet missing over Atlantic*  (Read 82386 times)

kea001

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Re: *Air France jet missing over Atlantic*
« Reply #125 on: June 12, 2009, 05:20:36 PM »
"It does not however explain why the jet was flown into such a violent storm cell when flights all around it were navigating through them without issues."

1. 'Flights all around it were navigating through them without any issue': FALSE
    Read my post on page 8 regarding TAM Linhas Aereas Airbus A330-200 registration PT-MVH performing flight JJ-  
    8098 from Sao Paulo Guarulhos (Brazil) to Paris.

2. On international routes, flights are typically spaced a minimum 10 minutes apart.
    Anything can develop within 10 minutes.  

3. Read the following incident: Pinnacle CRJ near Memphis June 11th, Severe Turbulence
    and take a look at how easy it is to get stuck in a cell
    http://www.liveatc.net/forums/listener-forum/incident-pinnacle-crj2-near-memphis-on-jun-11th-2009-severe-turbulence/
« Last Edit: June 12, 2009, 05:53:15 PM by kea001 »

Offline MathFox

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Re: *Air France jet missing over Atlantic*
« Reply #126 on: June 12, 2009, 05:57:10 PM »
I have done some modelling of "free convective flows" and from a physical perspective there is nothing that makes the convective flow in an old thunderstorm stronger than the flow in a "just developed" cell. The condensation heat of the water vapour drives the flow and that fresh cell can draw just as much (or maybe more) vapour from the ocean as an old storm.

How fast do cells develop? How clearly does a fresh cell (with only a minimal amount of water/ice) show up on the radar? OK, there's no rain or hail (could be supercooled water) in a fresh cell; but there will be turbulence, up- and down-drafts. Yes, the cell might develop in the air where "you happen to fly", not seeking you out but near-impossible to avoid anyway.

Offline Saabeba

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Re: *Air France jet missing over Atlantic*
« Reply #127 on: June 12, 2009, 11:17:29 PM »
While we have to try to come up for an explanation for the AF447 crash,

I would guess that statistical probabilities for this accident are extremely low.  If severe turbulence and unexpected storm cells were common on this route, then why would so many airlines attempt it daily?

From a statistical point of view, It's hard to believe that the airplane just hit a bad storm cell.




Offline aevins

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Re: *Air France jet missing over Atlantic*
« Reply #128 on: June 13, 2009, 12:31:18 AM »
While we have to try to come up for an explanation for the AF447 crash,

I would guess that statistical probabilities for this accident are extremely low.  If severe turbulence and unexpected storm cells were common on this route, then why would so many airlines attempt it daily?

From a statistical point of view, It's hard to believe that the airplane just hit a bad storm cell.


Again I cite the similarity to the crash of Southern Airways Flight 242, and the possibility of a weather radar malfunction. If you put Southern Airways Flight 242 and Birgenair Flight 301 together you have Air France Flight 447.

Offline Saabeba

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Re: *Air France jet missing over Atlantic*
« Reply #129 on: June 13, 2009, 10:15:01 PM »
From Times London:

"The sensors, called pitot tubes, are prone to getting clogged with ice and insects. One theory is that the “inconsistent” speed readings caused the automatic pilot to disengage...

It has emerged that the same sequence of events occurred in six cockpit emergencies reported by Airbus pilots over a year beginning in February 2008.....

In one incident, an Air France pilot issued a mayday call between Paris and Tokyo in turbulent weather after the loss of speed indication resulted in the disengagement of the automatic pilot and set off other alarms. In all six incidents, however, the pilots regained control of the aircraft.


Air France advised pilots on November 6 last year about the “significant number of incidents” in which false speed readings had confused the automated flight system.......

Among the sophisticated electronics on an Airbus A330 is a system that automatically pumps fuel aft when the plane climbs above 25,000ft. This alters the trim of the aircraft to improve fuel economy. It also alters the aircraft’s centre of gravity, making it harder to fly when in manual mode rather than autopilot.


Without the ability to read their speed, the crew of Flight 447 may have mistakenly believed there was a danger of stalling. If they applied extra thrust it could have tipped the plane out of control, tearing it apart in the turbulence.
"

kea001

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Re: *Air France jet missing over Atlantic*
« Reply #130 on: June 14, 2009, 06:33:25 AM »
In this article:
George Jonas: Flying through a mystery the author recounts a similar occurrence, Austral Líneas Aéreas Flight 2553
http://network.nationalpost.com/np/blogs/fullcomment/archive/2009/06/13/george-jonas-flying-through-a-mystery.aspx

Austral Líneas Aéreas Flight 2553
"the pitot tube—the primary instrument for measuring the aircraft's airspeed—froze when the aircraft passed through a cloud, blocking the instrument and causing it to give a false reading."

"Thinking that the aircraft was flying at dangerously low speeds, the pilots increased power to the engines. Far from flying at the low speed reported by the instruments however, the aircraft was actually exceeding its safe cruising speed, and far above a safe speed for deploying slats. During the deployment of the slats, one was torn off by the force of the high speed airflow traveling over the wing, which caused the plane to become unflyable and enter a steep descent."
http://en.wikipedia.org/wiki/Austral_L%C3%ADneas_A%C3%A9reas_Flight_2553



A couple of interesting photos on Aviation Herald,
http://www.avherald.com/h?article=41a81ef1/0022&opt=4096

1) picked up by merchant ship "Gammagas", one poster states it looks like "a complete speed brake  
    spoiler. It has damages suggesting that this piece could be acting when it was torn. See in the mid
    space were its hidraulic actuator was fixed."

2) Two flight attendant seats, folded.



Pitot tube contamination incidents:

Incident: SAS B737 near Oslo on May 30th 2009, bumble-bee strike

A SAS Norway Boeing 737-700, flight BU-4683/SK-4683 from Oslo Gardermoen (Norway) to Malaga,SP (Spain) with 134 passengers, had to return to Gardermoen Airport after the airspeed indicators started to disagree shortly after takeoff.

Mechanics found a bumble-bee had struck and embedded itsself into one of the pitot tubes of the airplane after takeoff, effectively blocking that dynamic port of the pitot system.
http://avherald.com/h?article=41a75abb

Birgenair Flight 301
Investigators suspected that some kind of insect could have created a nest inside the pitot tube.
http://en.wikipedia.org/wiki/Birgenair_Flight_301

Aeroperú Flight 603
masking tape accidentally left over the static ports
http://en.wikipedia.org/wiki/Aeroper%C3%BA_Flight_603


« Last Edit: June 14, 2009, 06:39:48 AM by kea001 »

Offline atcman23

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Re: *Air France jet missing over Atlantic*
« Reply #131 on: June 14, 2009, 07:40:35 AM »
Interesting pictures in the Aviation Herald article.  Certainly looks like this aircraft broke up in flight or in a dive.  I like how they added the American Airlines crash in New York in 2001 where the vertical stabilizer sheared off.  A completely different incident and different aircraft.  I hope they don't try and compare it to that flight.
Mark Spencer

kea001

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Re: *Air France jet missing over Atlantic*
« Reply #132 on: June 14, 2009, 09:23:25 AM »
I hope they don't try and compare it to that flight.

I don't disagree but I think it might become the 'flavour-of-the-week'.

Usually a story comes out of AP, Reuters, or UPI on the weekend and then you'll
have the basic kernel of an idea explode into a bunch of erroneous articles
that misrepresent the facts gleaned from the original one.

Air France jet sent message on rudder problem
Associated Press
http://www.google.com/hostednews/ap/article/ALeqM5iOegnahAFcEgwJZ4WKGkVz9Dgq5wD98QDHM80

Boeing Vs. Airbus :-D

How Airbus nearly killed 155 people according to an idiot
February 15, 2009 – 5:50 pm, by Ben Sandilands
http://blogs.crikey.com.au/planetalking/2009/02/15/how-airbus-nearly-killed-155-people-according-to-an-idiot/
« Last Edit: June 14, 2009, 09:29:45 AM by kea001 »

Offline atcman23

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Re: *Air France jet missing over Atlantic*
« Reply #133 on: June 15, 2009, 07:07:24 AM »
I like that last article you posted... written by a die-hard Boeing fanatic.  But he does make a few valid points in it.
Mark Spencer

Offline laylow

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Offline laylow

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Re: *Air France jet missing over Atlantic*
« Reply #135 on: July 02, 2009, 12:57:09 PM »
Some findings released.  They now say it did _not_ break up in the air.
http://news.aol.com/article/air-france-flight-447/553502

Offline joeyb747

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Re: *Air France jet missing over Atlantic*
« Reply #136 on: July 02, 2009, 04:56:36 PM »
...here is more...

"French: Air France plane hit the sea belly first"

"Analysis of the 600-odd pieces of the jet that have been recovered indicate the plane "was not destroyed in flight" and appeared to have hit the water intact and "belly first," gathering speed as it dropped thousands of feet, he said."

From this article:

http://www.comcast.net/articles/news-world/20090702/France.Crash.Investigation/
Aircraft Mechanic

Offline MathFox

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Re: *Air France jet missing over Atlantic*
« Reply #137 on: July 03, 2009, 07:12:42 AM »
For those interested in the official accident investigation reports:

English translation: http://www.bea.aero/docspa/2009/f-cp090601e1.en/pdf/f-cp090601e1.en.pdf
Original French: http://www.bea.aero/docspa/2009/f-cp090601e1/pdf/f-cp090601e1.pdf

[Note: the English version lacks the appendices, so it is a considerably smaller download.]