AF447
Joined: Jul 2007
Posts: 92
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From: Europe
Coffin Corner
One extra bit, which I cannot remember to have been posted yet. With these prerequisites
MAX AND OPT ALT FL357
ENGINE ANTI ICE ON -1100 FT
TOTAL ANTI ICE ON -1300 FT
Now, go figure what might happen when they had to
To me, this would be enough to draw the deadly picture.
- sea surface temperature was reported to be 27 - 28 degC, that is ISA+13.
- cruise speed M.82 (my assumption, to be corrected)
- weight approx. 210 t (took the same like snaproll3480)
MAX AND OPT ALT FL357
ENGINE ANTI ICE ON -1100 FT
TOTAL ANTI ICE ON -1300 FT
Now, go figure what might happen when they had to
- manually fly with alternate law (hence without stall protection) in turbulent air
- tried to fix the assumed possible sensor icing (whichever) with total anti ice on...
To me, this would be enough to draw the deadly picture.
.
Joined: Sep 2007
Posts: 388
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From: uk
Above optimum altitude
There is much talk of this aeroplane possibly being operated above optimum altitude or in "coffin corner" but so far I have not seen any reference to the obvious remedy.
I refer only to a serviceable aeroplane here but if anyone finds themselves with insufficient thrust to maintain speed through turbulence when above optimum altitude or above severe turbulence recommended levels, there is always the option of descent.
If it is serious and immediate enough such that speed is decaying even with max thrust, forget clearances, forget everything except getting that nose pointing downwards, with appropriate max thrust, to recover speed. Turn off track; use TCAS; anything but get that speed margin back, pronto but by definition the margin to MMO will be very small initially.
If significant unserviceabilities are added to the equation, the problems will magnify hugely but the basic principle remains.
Question: Does anyone advocate or ever been taught to use speedbrake to recover from MMO exceedances? I have found conflicting information in certain manufacturer's training manuals. I see a benefit in using a rapid application of speedbrake against thrust in certain conditions and perhaps avoid speed then reducing too far with consequent lag in thrust application again.
I refer only to a serviceable aeroplane here but if anyone finds themselves with insufficient thrust to maintain speed through turbulence when above optimum altitude or above severe turbulence recommended levels, there is always the option of descent.
If it is serious and immediate enough such that speed is decaying even with max thrust, forget clearances, forget everything except getting that nose pointing downwards, with appropriate max thrust, to recover speed. Turn off track; use TCAS; anything but get that speed margin back, pronto but by definition the margin to MMO will be very small initially.
If significant unserviceabilities are added to the equation, the problems will magnify hugely but the basic principle remains.
Question: Does anyone advocate or ever been taught to use speedbrake to recover from MMO exceedances? I have found conflicting information in certain manufacturer's training manuals. I see a benefit in using a rapid application of speedbrake against thrust in certain conditions and perhaps avoid speed then reducing too far with consequent lag in thrust application again.
Last edited by Starbear; 5th June 2009 at 17:35. Reason: To append question
Joined: May 2006
Aviation Qualifications: ATPL
Posts: 231
Likes: 5
From: Here, there and everywhere
BBB,
According to the ATC flight plan retreived from CFMU files, and which I have seen on another website, the filed speed was indeed M82.
I found the link to the image, here is it:
According to the ATC flight plan retreived from CFMU files, and which I have seen on another website, the filed speed was indeed M82.
I found the link to the image, here is it:
Joined: Jul 2008
Posts: 475
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From: UK
I don't think anybody has gone directly after the crew. However after going back over all the officially/unofficially (acars info) released information it does seem that the press at least are being driven in one direction.
I cannot remember any accident where acars data was released so quickly even if as a supposed unofficial leak which has greatly upset Air France.
Even then the data is supplied from a search function in a company software database and clips off anything prior to the flight.
Considering maintenance performed prior to the tragic Helios, Spanair and Excel flights was made openly public I do wonder what maintenance if any was performed on this aircraft prior to the RIO-CDG leg and why nothing has been mentioned?
You normally get some sort of statement.
I cannot remember any accident where acars data was released so quickly even if as a supposed unofficial leak which has greatly upset Air France.
Even then the data is supplied from a search function in a company software database and clips off anything prior to the flight.
Considering maintenance performed prior to the tragic Helios, Spanair and Excel flights was made openly public I do wonder what maintenance if any was performed on this aircraft prior to the RIO-CDG leg and why nothing has been mentioned?
You normally get some sort of statement.
Joined: Jun 2006
Posts: 3
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From: Texas
Will Fraiser-
Understood. (my earlier reply seems to have been deleted so I'll leave the commentary out.)
Would the A/P being on make any difference in the recommended use of A/T in sev/extr turb?
I seem to recall that the A/T systems in airbus' have an advanced algorithm for dealing with windshear & turb.?
Did/does AB and/or AF recommend leaving the A/T engaged for sev. or extr. turb.?
Understood. (my earlier reply seems to have been deleted so I'll leave the commentary out.)
Would the A/P being on make any difference in the recommended use of A/T in sev/extr turb?
I seem to recall that the A/T systems in airbus' have an advanced algorithm for dealing with windshear & turb.?
Did/does AB and/or AF recommend leaving the A/T engaged for sev. or extr. turb.?
Joined: Jan 2008
Posts: 798
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From: The Land of Beer and Chocolate
Safety Concerns
If I remember right, the original statements from Air France said that the last maintainence AF447 had was back in April. Nothing about anything done in Rio before the ill-fated flight.
If I remember right, the original statements from Air France said that the last maintainence AF447 had was back in April. Nothing about anything done in Rio before the ill-fated flight.
Joined: Jan 2008
Posts: 694
Likes: 1
From: US/EU
AP is reporting a memo from AF to pilots saying the airline is replacing pitot tubes on all medium- and long-haul AirBus aircraft with newer models within the next few weeks:
Air France says it's replacing flight instruments - Yahoo! News
Air France says it's replacing flight instruments - Yahoo! News
Joined: Jan 2002
Posts: 286
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From: USA
Could there be a good possibility that the airplane may have gone down intact. I suggest this on the thus far slow or lack of discovery of a debris footprint. Had the airplane failed at altitude, given the altitude, speed, and winds aloft, then one could reasonably expect an extended area of debris which would track with the airplane as it descended. It would therefore be quite large, and I doubt it would have been difficult to locate.
To compare, I recall all too well the Lockerbie situation with the inflight breakup of PA and the area that was affected. The heavy portion fell in the village, and nearby area, but countless other items extended for miles. Some large, some small.
On the other hand, MS990 created only two relatively small debris field in the Atlantic. One 62 X 66 meters, and the other 83 X 73. This airplane entered the water mostly intact. Radar coverage made it quickly discovered.
To compare, I recall all too well the Lockerbie situation with the inflight breakup of PA and the area that was affected. The heavy portion fell in the village, and nearby area, but countless other items extended for miles. Some large, some small.
On the other hand, MS990 created only two relatively small debris field in the Atlantic. One 62 X 66 meters, and the other 83 X 73. This airplane entered the water mostly intact. Radar coverage made it quickly discovered.
Joined: Aug 2005
Posts: 1,693
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From: fairly close to the colonial capitol
>>> Request - Please Read <<<
It would be helpful to the readability and usefulness of this thread if posters would kindly refrain from quoting "newspaper", "news media", "Network XYZ aviation experts", etc theories on what happened to AF447. These articles and posits are highly speculative and authored by people that most likely have less knowledge of transport category aircraft operations than our cabin crew.
Your cooperation will assist in keeping this thread on at least a soft focus.
Reports of new information are of course most welcome.
Your cooperation will assist in keeping this thread on at least a soft focus.
Reports of new information are of course most welcome.
Joined: Jul 1999
Posts: 3,040
Likes: 0
From: 58-33N. 00-18W. Peterborough UK
AP is reporting a memo from AF to pilots saying the airline is replacing pitot tubes on all medium- and long-haul AirBus aircraft with newer models within the next few weeks:
Airbus Industrie A330 Series Aeroplanes
AD/A330/1 Pitot Probes 12/2002
Background: The French Direction Générale de l’Aviation Civile has advised that operators have reported loss or fluctuation of airspeed when flying through extreme meteorological conditions. Further to an investigation, the presence of ice crystals and/or water exceeding the current limits of the initial specification of Rosemount pitot probes P/N 0851GR is considered the most probable cause of these airspeed discrepancies.
This Directive requires the installation of pitot probes meeting more stringent
qualification requirements.
Barry James Reid McKay
Delegate of the Civil Aviation Safety Authority
17 October 2002
http://www.casa.gov.au/wcmswr/_asset...0/a330-001.pdf
Joined: Jul 2008
Posts: 475
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From: UK
@vapilot2004 you are probably correct but replacement of all pitot probes and confirmed by Air France is relevant.
The article says the process has been "ongoing" and should be complete within a few weeks.
Therefore I expect one of the first questions tomorrow by a journalist to be "have they been replaced on AF447 and if so when?"
I will refrain from speculation until that question has been answered. However the manner and format of the acars messages is lets say non conventional.
The article says the process has been "ongoing" and should be complete within a few weeks.
Therefore I expect one of the first questions tomorrow by a journalist to be "have they been replaced on AF447 and if so when?"
I will refrain from speculation until that question has been answered. However the manner and format of the acars messages is lets say non conventional.
Joined: Jun 2009
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From: MURDO
Altitude
One item I've not seen enter the discussion:
Based on the flight plan posted on Tim Vasquez' excellent discussion, the following jumped at me:
"INTOL/M082F350 UN873 SALPU/M082F370 UN873..."
Decoded, this means the flight intended to cross INTOL at Mach 0.82 and FL350, proceed along the UN873 airway and cross SALPU at Mach 0.82 and FL370. In other words, the canned flight plan called for a cruise climb from FL350 to FL370 between INTOL and SALPU and before disappearing.
Do we know if this cruise-climb was performed? If it was, would not the A330 have been even more deeply embedded into its "coffin corner?"
DCr
Based on the flight plan posted on Tim Vasquez' excellent discussion, the following jumped at me:
"INTOL/M082F350 UN873 SALPU/M082F370 UN873..."
Decoded, this means the flight intended to cross INTOL at Mach 0.82 and FL350, proceed along the UN873 airway and cross SALPU at Mach 0.82 and FL370. In other words, the canned flight plan called for a cruise climb from FL350 to FL370 between INTOL and SALPU and before disappearing.
Do we know if this cruise-climb was performed? If it was, would not the A330 have been even more deeply embedded into its "coffin corner?"
DCr
Joined: Jun 2001
Posts: 5,896
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From: Rockytop, Tennessee, USA
Precise digital presentations of max and min speeds were first available on the 320 have made the term redundant.