AF 447 Search to resume
Join Date: Jun 2009
Location: NYC
Age: 72
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
The aircraft is not in the area we looked in and so, she continued flying for far longer than we are expecting.
But why weren't any indications of parts of her found (as far as we know at this time), during the last search go-round? I think they were simply looking in the wrong areas.
I understand the drift analyses (thanks to mm43 and the others who have made these understandable), what I really don't understand is why they used them to determine the recent search area. *Some* parts of the airframe had to go straight down (or as straight down as possible in whatever conditions prevail out there). It would be nice if they could find, say, the engines or a couple of robust structural pieces in order to more closely pinpoint the actual impact location -- and then work from there -- the FDR and CVR might be closer than they think.
I guess that's why I mentioned using ROVs similar to the ones currently being used in the Gulf a couple of weeks ago. JD-EE and auv-ee had a nice discussion of their capabilities and provided a couple of links to similar kit. And yeah, it looks doable, slow, but doable.
Join Date: Jul 2009
Location: Planet Earth
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
@CONF iture
We also know, that this was the scene of a monster storm system. For example, who is to say that the VS and other pieces of debris were not sucked up by waterspouts and deposited at the site where they were discovered a few days later.
But the main argument has to be that a well-funded well-equipped year-long search operation came up with no evidence of the aircraft's presence (debris, signals from the pingers, etc.,) beyond what was discovered in the immediate aftermath of the event.
We also know, that this was the scene of a monster storm system. For example, who is to say that the VS and other pieces of debris were not sucked up by waterspouts and deposited at the site where they were discovered a few days later.
But the main argument has to be that a well-funded well-equipped year-long search operation came up with no evidence of the aircraft's presence (debris, signals from the pingers, etc.,) beyond what was discovered in the immediate aftermath of the event.
Guest
Posts: n/a
CogSim
Personally I think it unlikely that waterspouts redistributed debris. BEA have determined satisfactorily (to them) that the a/c was intact at impact. This rules out what might have resulted (and has, in many unfortunate encounters) vis a vis in-flight loss of parts. A large a/c in upset and rapid descent would ordinarily be vulnerable to such disintegration; throw in large hail, massive updraft and 'blended' shear, it might have resulted in a shower of small bits and pieces. For instance, golf ball hail lifted at fifty knots against an airframe descending at two hundred would have been the same as flying through plum size gravel, yet there is no evidence on recovered materials of such an event. I have seen resin/fiber radomes after separation at altitude, the deformation resembles what we see here, with 447. The fractures of 447's radome resemble those seen in "flattening" (airstream) impact in other events.
As much room as there is in this accident for "outlier" theories, whatever happened most likely occurred in pedestrian fashion; this does not prevent gaining knowledge in a general way that is helpful in making safer the future of air travel. It is human nature to "want" a certain explanation, whether it is "Lightning", "Weather", or "Fluke". No one wants to admit to simple (and preventable) cause.
tailwinds,
bear
Personally I think it unlikely that waterspouts redistributed debris. BEA have determined satisfactorily (to them) that the a/c was intact at impact. This rules out what might have resulted (and has, in many unfortunate encounters) vis a vis in-flight loss of parts. A large a/c in upset and rapid descent would ordinarily be vulnerable to such disintegration; throw in large hail, massive updraft and 'blended' shear, it might have resulted in a shower of small bits and pieces. For instance, golf ball hail lifted at fifty knots against an airframe descending at two hundred would have been the same as flying through plum size gravel, yet there is no evidence on recovered materials of such an event. I have seen resin/fiber radomes after separation at altitude, the deformation resembles what we see here, with 447. The fractures of 447's radome resemble those seen in "flattening" (airstream) impact in other events.
As much room as there is in this accident for "outlier" theories, whatever happened most likely occurred in pedestrian fashion; this does not prevent gaining knowledge in a general way that is helpful in making safer the future of air travel. It is human nature to "want" a certain explanation, whether it is "Lightning", "Weather", or "Fluke". No one wants to admit to simple (and preventable) cause.
tailwinds,
bear
Monster Storm System
We also know, that this was the scene of a monster storm system.
Join Date: Mar 2001
Location: us
Posts: 694
Likes: 0
Received 0 Likes
on
0 Posts
jimbeetle, the Brazilian air force's search grid on the first day of searching overflew the last known position, and they could not have been that blind to have missed the debris field, fuel or hydraulic sheen, etc. If they felt the scan of the area searched that first day was obscured because of visibility, I am quite certain that grid would have been immediately repeated.
Join Date: Apr 2008
Location: Philippines
Posts: 37
Likes: 0
Received 0 Likes
on
0 Posts
It does not necessarily need to be a thunderstorm.
Mother Nature can be a bitch!
Some years ago I was on the mid north coast of NSW driving south on one of those days you are glad not to be on a golf course.
Scattered cloud at around 5,000 ft.intermittent rain and cold,
I saw two cloud formations converging on each other, and as a gliding man stopped to watch.
It was truly amazing when the two formations collided, the result was an instantaneous downward flow of cloud, not unlike a waterfall. The speed was astonishing, and so was the damage.
About two miles further down the Pacific Highway, a swathe had been cut about 200 yards wide. An uprooted, very old fig tree a few cows, power lines and general bush had been demolished.
I truly hate to think what could have happened to any aircraft hitting such a system.
Mother Nature can be a bitch!
Some years ago I was on the mid north coast of NSW driving south on one of those days you are glad not to be on a golf course.
Scattered cloud at around 5,000 ft.intermittent rain and cold,
I saw two cloud formations converging on each other, and as a gliding man stopped to watch.
It was truly amazing when the two formations collided, the result was an instantaneous downward flow of cloud, not unlike a waterfall. The speed was astonishing, and so was the damage.
About two miles further down the Pacific Highway, a swathe had been cut about 200 yards wide. An uprooted, very old fig tree a few cows, power lines and general bush had been demolished.
I truly hate to think what could have happened to any aircraft hitting such a system.
Join Date: Jul 2009
Location: France - mostly
Age: 84
Posts: 1,682
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by smilin ed
"NEVER FLY THROUGH A THUNDERSTORM!"
regards,
HN39
Join Date: Jun 2009
Location: NNW of Antipodes
Age: 81
Posts: 1,330
Received 0 Likes
on
0 Posts
Originally posted by HN39 ...
There is no evidence to suggest that any particular cell was exceptionally violent.
There is no evidence to suggest that any particular cell was exceptionally violent.
Originally posted by wes wall ...
.... is any search being conducted now, or, when will it resume.
.... is any search being conducted now, or, when will it resume.
mm43
Join Date: Jan 2005
Location: W of 30W
Posts: 1,916
Likes: 0
Received 0 Likes
on
0 Posts
It is all very good to put forward those representations about AF447, but then you have to do the same about LH and IB. Look at the scale at the bottom of the second graphic and draw your own conclusion. LH was 10 miles west of the airway, IB was 30 east.
Join Date: Jul 2009
Location: France - mostly
Age: 84
Posts: 1,682
Likes: 0
Received 0 Likes
on
0 Posts
Pitch, power and AoA
EDIT:: This post contained a link to a faulty graph and has been withdrawn. I apologize for any inconvenience.
HN39
HN39
Last edited by HazelNuts39; 23rd Jun 2010 at 22:05. Reason: faulty graph
Hazelnuts
Other than tops at 50K (possibly higher, see the graphic a few posts up in post #1551) ... so there is some evidence to suggest a powerful cell, or storm system. Vertical development.
As I understand thunderstorms, the greater the vertical development, the greater the energy, and thus "violence" in a storm system or cell. I got to investigate a ground mishap some years ago that resulted from a fast moving cell delivering a microburst that pushed a parked ground services truck (no, it wasn't chocked) into a couple of aircraft, causing no small amount of damage.
It is common to get thunderstorms in Texas. We get SIGMETS regularly. There are violent thunderstorms a plenty here. I'll defer to a professional meteorologist here, but there seems to be a correlation between violent thunderstorms, in comparative cases. Those displaying tops upwards of 50K tend to be associated with greater voilence than less well developed (vertically) cells or lines. About three weeks ago, in Southern Texas, a storm system generated localized hurricane force winds that knocked off some roofs, kicked over trees, and did various amounts of damage.
Is that not violent? Is it exceptionally violent? Would you have wanted to be flying through the top of that?
There is no evidence to suggest that any particular cell was exceptionally violent.
As I understand thunderstorms, the greater the vertical development, the greater the energy, and thus "violence" in a storm system or cell. I got to investigate a ground mishap some years ago that resulted from a fast moving cell delivering a microburst that pushed a parked ground services truck (no, it wasn't chocked) into a couple of aircraft, causing no small amount of damage.
It is common to get thunderstorms in Texas. We get SIGMETS regularly. There are violent thunderstorms a plenty here. I'll defer to a professional meteorologist here, but there seems to be a correlation between violent thunderstorms, in comparative cases. Those displaying tops upwards of 50K tend to be associated with greater voilence than less well developed (vertically) cells or lines. About three weeks ago, in Southern Texas, a storm system generated localized hurricane force winds that knocked off some roofs, kicked over trees, and did various amounts of damage.
Is that not violent? Is it exceptionally violent? Would you have wanted to be flying through the top of that?
Last edited by Lonewolf_50; 23rd Jun 2010 at 12:58.
Join Date: Mar 2001
Location: us
Posts: 694
Likes: 0
Received 0 Likes
on
0 Posts
CONFiture,
The meteorology is dynamic, and I don't believe I've seen a mapping of the atmospheric conditions existing at the time that LH and IB were on the track post ORARO.
If the crew of AF447 reverted to SELCAL mode (and perhaps even switched to the DAKAR frequency) at 1 h 35 min, they probably missed any communication that may have occurred between ATLANTICO and LH507 on its deviation. Transcripts of communications between ATLANTICO and the LH and IB flights have not been released, nor is there mention in the interim report of whether AF459 was alert to communications between ATLANTICO and IB6024, flying about 25 minutes ahead of them.
The meteorology is dynamic, and I don't believe I've seen a mapping of the atmospheric conditions existing at the time that LH and IB were on the track post ORARO.
Flight LH507 (B747-400) preceded flight AF447 by about twenty minutes at FL350.
The crew reported that it flew at the upper limit of the cloud layer and then in the clouds in the region of ORARO. In this zone they saw green echoes on the radar on their path, which they avoided by changing their route by about ten nautical miles to the west. While flying through this zone, which took about fifteen minutes, they felt moderate turbulence and did not observe any lightning. They lowered their speed to the speed recommended in turbulent
zones. They saw bright St Elmo’s fire on the windshield on the left-hand side. The crew listened into the 121.5 MHz frequency throughout the flight without hearing any message from AF447.
....
Flight IB6024 (Airbus A340) passed at the level of the ORARO waypoint at FL370 approximately twelve minutes after AF447.
The crew saw AF447 take off while taxiing at Rio de Janeiro. When passing the INTOL waypoint, they encountered conditions typical of the inter-tropical convergence zone. These conditions were particularly severe 70 NM to 30 NM before the TASIL waypoint. They moved away from the route by about 30 NM to the east to avoid cumulonimbus formations with a significant vertical development, and then returned to the airway in clear skies close to the TASIL waypoint.
....
Flight AF459 (Airbus A330-203) passed at the level of the ORARO waypoint approximately 37 minutes after l’AF447.
The sky was clear but the half-moon, visible to the aft left of the aircraft, did not make it possible to see the contour of the cloud mass distinctly. After flying through a turbulent zone in the head of a cumulus congestus formation at the level of NATAL, without having detected this zone on the radar, he selected gain in MAX mode. At about 2 h 00, he observed a first echo that differed significantly depending on whether the radar’s gain was in CAL or MAX
mode. The TILT was set between -1° and 1.5°. He decided to take evasive action to the west, which resulted in a deviation of 20 NM to the left of the route. During this evasive action, a vast squall line with an estimated length of 150 NM appeared on the screen, which was set to a scale of 160 NM. The echoes were yellow and red when the radar was set with gain on the MAX position and green and yellow when the gain was on the CAL position. No
lightning was observed.
ATLANTICO control, informed by the crew of their decision to avoid this squall line by taking evasive action to the east, asked them to return to the airway as soon as they could. This evasive action meant the aircraft flew between 70 and 80 NM to the right of the planned route. In addition, the crew was authorised to climb from FL350 to FL370.
The crew reported that it flew at the upper limit of the cloud layer and then in the clouds in the region of ORARO. In this zone they saw green echoes on the radar on their path, which they avoided by changing their route by about ten nautical miles to the west. While flying through this zone, which took about fifteen minutes, they felt moderate turbulence and did not observe any lightning. They lowered their speed to the speed recommended in turbulent
zones. They saw bright St Elmo’s fire on the windshield on the left-hand side. The crew listened into the 121.5 MHz frequency throughout the flight without hearing any message from AF447.
....
Flight IB6024 (Airbus A340) passed at the level of the ORARO waypoint at FL370 approximately twelve minutes after AF447.
The crew saw AF447 take off while taxiing at Rio de Janeiro. When passing the INTOL waypoint, they encountered conditions typical of the inter-tropical convergence zone. These conditions were particularly severe 70 NM to 30 NM before the TASIL waypoint. They moved away from the route by about 30 NM to the east to avoid cumulonimbus formations with a significant vertical development, and then returned to the airway in clear skies close to the TASIL waypoint.
....
Flight AF459 (Airbus A330-203) passed at the level of the ORARO waypoint approximately 37 minutes after l’AF447.
The sky was clear but the half-moon, visible to the aft left of the aircraft, did not make it possible to see the contour of the cloud mass distinctly. After flying through a turbulent zone in the head of a cumulus congestus formation at the level of NATAL, without having detected this zone on the radar, he selected gain in MAX mode. At about 2 h 00, he observed a first echo that differed significantly depending on whether the radar’s gain was in CAL or MAX
mode. The TILT was set between -1° and 1.5°. He decided to take evasive action to the west, which resulted in a deviation of 20 NM to the left of the route. During this evasive action, a vast squall line with an estimated length of 150 NM appeared on the screen, which was set to a scale of 160 NM. The echoes were yellow and red when the radar was set with gain on the MAX position and green and yellow when the gain was on the CAL position. No
lightning was observed.
ATLANTICO control, informed by the crew of their decision to avoid this squall line by taking evasive action to the east, asked them to return to the airway as soon as they could. This evasive action meant the aircraft flew between 70 and 80 NM to the right of the planned route. In addition, the crew was authorised to climb from FL350 to FL370.
Join Date: Jun 2009
Location: in a plasma cocoon
Age: 53
Posts: 244
Likes: 0
Received 0 Likes
on
0 Posts
pich & thrust procedure, flight enveloppe
HN39, thank you for your simplified computation. I am surprised that the Mach number can decrease so close to M0.60 (with CLB thrust), which is close to the lower boundary of the flight enveloppe as far as I can remember (in such a configuration ~M0.58). Given that this latter can be further increased above M0.60 by a turn or turbulence, what if the AF 447 lost its flight control/protections (low speed protection, turn coordination, etc...) during a late (if the red areas appeared lately on the weather radar like in some past cases) manoeuver/turn to avoid the closest high top Cb cell (3NM deviation to the west of the normal trajectory) and with possibly increasing turbulences ?
(the stall alarms of the Air Caraïbe flight occurred around 4.3° of AoA I think)
Back to the past cases analysed by the BEA in the 2nd interim report, does the BEA suggest that the pich & thrust procedure was rarely applied (thrust remaining locked and no pich setting to 5°) ?
Jeff
(the stall alarms of the Air Caraïbe flight occurred around 4.3° of AoA I think)
Back to the past cases analysed by the BEA in the 2nd interim report, does the BEA suggest that the pich & thrust procedure was rarely applied (thrust remaining locked and no pich setting to 5°) ?
Jeff
Join Date: Jul 2009
Location: France - mostly
Age: 84
Posts: 1,682
Likes: 0
Received 0 Likes
on
0 Posts
Pitch & thrust
Hyperveloce;
EDIT:: I regret that the first graph was faulty. I'll replace it by a correct version when ready.
Perhaps I misunderstand your repeated question, but BEA's words are:
HN39
EDIT:: I regret that the first graph was faulty. I'll replace it by a correct version when ready.
Originally Posted by hyperveloce
does the BEA suggest that the pitch & thrust procedure was rarely applied?
For the cases studied, the recording of the flight parameters and the crew
testimony do not suggest application of the memory items(13) in the unreliable
airspeed procedure:
testimony do not suggest application of the memory items(13) in the unreliable
airspeed procedure:
Last edited by HazelNuts39; 23rd Jun 2010 at 22:09. Reason: graph withdrawn
Join Date: Oct 2006
Location: Gone Flying...
Age: 63
Posts: 270
Likes: 0
Received 0 Likes
on
0 Posts
Saturn V:
In my two decades of experience flying in the Atlantic (North and South), I must say that I have never received any alert message made by Atlantico or Dakar regarding weather conditions that could affect my flights. Quite contrary to the New York, Gander and S. Maria, that sometimes call us for the transmission of SIGMETS or PIREPS, we see nothing like in the South. The only clue of "trouble ahead" (appart from your own ops and met data) is the pilot-to-pilot freq.
...
IMHO, the attitude to be set up in case of unreliable airspeed at high altitudes should be, in fact, 2.5º (not 5º).
Although QRH Memory items are (for the A330):
- Below THRUST REDUCTION ALT 15º;
- Above TR ALT and Below FL100 10º
- Above FL100, 5º.
this numbers are to be used at lower altitudes or close to the terrain. If AF447 pilots have used that attitude by memory, and specially if they kept a low power set up, that must have contributed to enter the Stall.
We know by experience that, the use of 5º is (in most cases) beyond available power, especially when flying in the “coffin corner”, as most pilots do. What we actually do in my company, is to record every hour our actual attitude (and check that stand-by att (or ISIS) is not precessing) together with actual N1. We do know by heart that our average attitude should be around 2,5º up. If one finds himself in the middle of a storm in UAI situation, why then force the envelope with a 5º (ATT) climb, risking to stall the aircraft?
If the crew of AF447 reverted to SELCAL mode (and perhaps even switched to the DAKAR frequency) at 1 h 35 min, they probably missed any communication that may have occurred between ATLANTICO and LH507 on its deviation. Transcripts of communications between ATLANTICO and the LH and IB flights have not been released, nor is there mention in the interim report of whether AF459 was alert to communications between ATLANTICO and IB6024, flying about 25 minutes ahead of them.
For the cases studied, the recording of the flight parameters and the crew
testimony do not suggest application of the memory items(13) in the unreliable
airspeed procedure
testimony do not suggest application of the memory items(13) in the unreliable
airspeed procedure
IMHO, the attitude to be set up in case of unreliable airspeed at high altitudes should be, in fact, 2.5º (not 5º).
Although QRH Memory items are (for the A330):
- Below THRUST REDUCTION ALT 15º;
- Above TR ALT and Below FL100 10º
- Above FL100, 5º.
this numbers are to be used at lower altitudes or close to the terrain. If AF447 pilots have used that attitude by memory, and specially if they kept a low power set up, that must have contributed to enter the Stall.
We know by experience that, the use of 5º is (in most cases) beyond available power, especially when flying in the “coffin corner”, as most pilots do. What we actually do in my company, is to record every hour our actual attitude (and check that stand-by att (or ISIS) is not precessing) together with actual N1. We do know by heart that our average attitude should be around 2,5º up. If one finds himself in the middle of a storm in UAI situation, why then force the envelope with a 5º (ATT) climb, risking to stall the aircraft?
Join Date: Jun 2009
Location: NYC
Age: 72
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
SaturnV,
But according to the BEA press release on June 2nd, "The Brazilian authorities have confirmed to the BEA that floating debris has been observed in the search zone."
Since this was part of the initial search, my *assumption* is that the "search zone" was someplace, somehow, somewhere close to the LKP.
We've all seen these pictures before, but slides 5 through 10 of Status of sea search operations as of 17 June 2009 show a very defined drift of debris and bodies from "somewhere" near the LKP (whether LKP itself or off to the West or Southwest as some folks surmise). Initial recoveries on 6 June were about 50 km north of LKP; on 7 June many recoveries were in the same area as on the 6th, with more from the NW, with one just about 10 km NW of LKP.
Anyway, all that is basically an aside to my main point -- not everything floats -- some hunks of the airframe are somewhere close to where AF447 impacted. And my assumption is that is somewhere not far from the LKP. I guess I still can't wrap my mind around the BEA assumption that the FDR can CVR would drift so far.
Sorry about the wishy-washy language, but everything about 447 so far is surmise and assumption. Plus it's the usual CYA from an old intel analyst.
jimbeetle, the Brazilian air force's search grid on the first day of searching overflew the last known position, and they could not have been that blind to have missed the debris field, fuel or hydraulic sheen, etc. If they felt the scan of the area searched that first day was obscured because of visibility, I am quite certain that grid would have been immediately repeated.
Since this was part of the initial search, my *assumption* is that the "search zone" was someplace, somehow, somewhere close to the LKP.
We've all seen these pictures before, but slides 5 through 10 of Status of sea search operations as of 17 June 2009 show a very defined drift of debris and bodies from "somewhere" near the LKP (whether LKP itself or off to the West or Southwest as some folks surmise). Initial recoveries on 6 June were about 50 km north of LKP; on 7 June many recoveries were in the same area as on the 6th, with more from the NW, with one just about 10 km NW of LKP.
Anyway, all that is basically an aside to my main point -- not everything floats -- some hunks of the airframe are somewhere close to where AF447 impacted. And my assumption is that is somewhere not far from the LKP. I guess I still can't wrap my mind around the BEA assumption that the FDR can CVR would drift so far.
Sorry about the wishy-washy language, but everything about 447 so far is surmise and assumption. Plus it's the usual CYA from an old intel analyst.