Afriqiyah Airbus 330 Crash
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Two things do not fit here:
1) I would expect the VOR approach track to be further to the north than drawn above - it is a runway approach and the FAT would normally cross the centreline around about the MAP which is the 'D' NDB, so they were more than '300m south'
2) What do we do with the Alitalia 'eye-witness report' of a pitch attitude of '20 degrees nose down'? It seems to suggest that they in fact saw the dive AFTER the initial impact.
1) I would expect the VOR approach track to be further to the north than drawn above - it is a runway approach and the FAT would normally cross the centreline around about the MAP which is the 'D' NDB, so they were more than '300m south'
2) What do we do with the Alitalia 'eye-witness report' of a pitch attitude of '20 degrees nose down'? It seems to suggest that they in fact saw the dive AFTER the initial impact.
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Schubinho, thanks for that. What i still cant comprehend is the fact that the wings are all the way to the front of the crash site with no debris what so ever in front of them. The wings also look to be perfectly next to each other. Where did the nose of the plane go?
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Lots of good speculation here...I vote for saw R/W at last min and tried to make the approach fit by forcing the landing. Either hit the ground with left wing while maneuvering or belly on late missed approach.. 
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Hello,
C-SAR, thank you, it would be very nice if you could look at the initial impact zone, and if those "white" traces are related or not to impact, and check roughly the width of the initial trail. If you can walk the zone, looking at what are the first debris would be helpful.
I think also that it is not wheels contact that left this track, seems too tiny.
Contact could be made nose up with full power applied for a go around; tail hit first and trailed on the ground. Mosque road caused a bump further weakening the airframe and caused tail separation which rotated, then cabin came down after the mosque and starting to desintegrate along the trail. From initial contact to where wings are lying, the distance is between 800-900 meters. Part of the landing gear is lying near the last road just before the airport's limit.
I don't think that "Alitalia rumor" is very relevant. Beside, thank you for posting this Dutch link as the full trail travelling is very interesting.
C-SAR, thank you, it would be very nice if you could look at the initial impact zone, and if those "white" traces are related or not to impact, and check roughly the width of the initial trail. If you can walk the zone, looking at what are the first debris would be helpful.
I think also that it is not wheels contact that left this track, seems too tiny.
Contact could be made nose up with full power applied for a go around; tail hit first and trailed on the ground. Mosque road caused a bump further weakening the airframe and caused tail separation which rotated, then cabin came down after the mosque and starting to desintegrate along the trail. From initial contact to where wings are lying, the distance is between 800-900 meters. Part of the landing gear is lying near the last road just before the airport's limit.
I don't think that "Alitalia rumor" is very relevant. Beside, thank you for posting this Dutch link as the full trail travelling is very interesting.
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Originally Posted by Nickdj
. What i still cant comprehend is the fact that the wings are all the way to the front of the crash site with no debris what so ever in front of them. The wings also look to be perfectly next to each other. Where did the nose of the plane go?
BOAC,
It has been mentioned that the SOP was selected/selected, due to lack of approval of anything better. Which would lead toward the VOR rather than the FAT.
I have a suspicion that this trench is deeper and more aggressive than it may appear:
It is difficult to scale its depth from that photo.
If the aircraft started a go-around (ie application of ga thrust and gear up) but for some reason rapidly headed down, then it may well have hit hard and more nose down than initially imagined (as per the eye witness).
A nose down attitude would explain the lack of frontal remains - most identifiable bits seem to be from wing root backwards.
A hard vertical g on impact could cause the wing roots to snap (allowing the wing assemblies to travel further before stopping). The tail assembly would be hard to guess, but it clearly has done some acrobatics - given the broken fin tip and the final orientation - but the fact that it's intact adds weight to a nose down impact.
It has been mentioned that the SOP was selected/selected, due to lack of approval of anything better. Which would lead toward the VOR rather than the FAT.
I have a suspicion that this trench is deeper and more aggressive than it may appear:
It is difficult to scale its depth from that photo.
If the aircraft started a go-around (ie application of ga thrust and gear up) but for some reason rapidly headed down, then it may well have hit hard and more nose down than initially imagined (as per the eye witness).
A nose down attitude would explain the lack of frontal remains - most identifiable bits seem to be from wing root backwards.
A hard vertical g on impact could cause the wing roots to snap (allowing the wing assemblies to travel further before stopping). The tail assembly would be hard to guess, but it clearly has done some acrobatics - given the broken fin tip and the final orientation - but the fact that it's intact adds weight to a nose down impact.
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For what it's worth, my theory (everyone else is assuming so I may as well) ...
Using Schubinho's calculations as a guide it hit the ground flat but slightly tail first, enough to loosen the tail but not to actually separate it, slid for a bit until the tail cone and subsequently the whole tail section came off (from here on there's lots of debris from stuff falling out the rear and from the fuselage breaking apart). The tail tumbles at least once, hence the damage on it, until it stops. The wings and centre section being the strongest part of the aircraft and still possible powered by at least one engine remain virtually intact until they hit the fence. In effect the rest of the fuselage has broken up around the wings and and wing box.
The only thing that argues against this in Schubinho's picture is that, if the track is of the belly of the aircraft there should be tracks from the engines sliding along the ground
(Looks like Takata beat me to it!)
Using Schubinho's calculations as a guide it hit the ground flat but slightly tail first, enough to loosen the tail but not to actually separate it, slid for a bit until the tail cone and subsequently the whole tail section came off (from here on there's lots of debris from stuff falling out the rear and from the fuselage breaking apart). The tail tumbles at least once, hence the damage on it, until it stops. The wings and centre section being the strongest part of the aircraft and still possible powered by at least one engine remain virtually intact until they hit the fence. In effect the rest of the fuselage has broken up around the wings and and wing box.
The only thing that argues against this in Schubinho's picture is that, if the track is of the belly of the aircraft there should be tracks from the engines sliding along the ground
(Looks like Takata beat me to it!)
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Originally Posted by justawanab
The only thing that argues against this in Schubinho's picture is that, if the track is of the belly of the aircraft there should be tracks from the engines sliding along the ground
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In a conventional low-wing monoplane, the centre of pressure (lift) is aft of the centre of gravity. The aircraft is kept in balance by a downward force on the tailplane. If the tailplane fails, the result is an instantaneous and massive nose-down pitch, which could result in further structural failure.
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Originally Posted by 100%
Which would lead toward the VOR rather than the FAT.
Sorry - my mistake. Of course it is.
As the VOR procedure is 4° offset from the runway, most of the approach should be with the a/c to the North of the c/l. My point I tried to make (badly) was that rather than the aircraft fly a perfect managed path, the pilot may have done something else with his track knob that took him ultimately towards the VOR (past the point where he should turn left and align with the runway). The FMC wouldn't do that.
Selected/selected is just an Airbus term, meaning lateral and vertical modes are controlled by the track knob and the FPA (flight path angle) knob. The alternative is managed for either plane (which is like LNAV/VNAV for Boeing pilots).
As the VOR procedure is 4° offset from the runway, most of the approach should be with the a/c to the North of the c/l. My point I tried to make (badly) was that rather than the aircraft fly a perfect managed path, the pilot may have done something else with his track knob that took him ultimately towards the VOR (past the point where he should turn left and align with the runway). The FMC wouldn't do that.
Selected/selected is just an Airbus term, meaning lateral and vertical modes are controlled by the track knob and the FPA (flight path angle) knob. The alternative is managed for either plane (which is like LNAV/VNAV for Boeing pilots).
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Originally Posted by Neptunus Rex
In a conventional low-wing monoplane, the centre of pressure (lift) is aft of the centre of gravity. The aircraft is kept in balance by a downward force on the tailplane. If the tailplane fails, the result is an instantaneous and massive nose-down pitch, which could result in further structural failure.
This explain why the cabin was so fragmented and nearly no big part of the fuselage survived (cockpit was nearly flatened). Also the state of the engine, fragments of the landing gear around this place and further (it was possibly still down but never touched ground). The surviving boy could have been ejected when the tail fall appart. He certainly was seated on the rear rows.
S~
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Late Go Around?
UNCTUOUS
http://www.pprune.org/5694361-post365.html
I'd appreciate it you would not copy-and-paste my previous post (#360) and use it as your own, complete with my observations. You do know how to quote text so please, whenever you agree with what someone else has written and/or linked to, quote them properly and then add whatever you want outside the quote-box!
PJ2
Thanks for the composite. I wanted to do something similar when I found the video last night but time (I needed to go to bed) did not allow me to :-(
Schubinho
I do not believe the markings are caused by the (main) landing gear. It more looks like the belly of the plane (your possibility #1) which simply slided some 200 meters until it encountered the road running north-west near the mosque and which appears to be slightly higher. If the main gear would have been down at initial impact, they would have been ripped off almost instantly or, posibly when they hit the aforementioned road, and thus be located within the vicinity of the tail-section.
Unfortunately, we do not know (at least not from the aerial shot I linked to as video stops there) if there is any more debris after what appears to be the wingbox (and which would be closer to the runway).
--
As others have already questioned, would a scenario where the pilots initiated a go around applying TOGA (and gear up) perhaps explain the lack of gear-tracks on the ground and the fact that the wings (though still unconfirmed these are actually the wings) appear some 730 meters from initial impact area? Would engines still running at TOGA (or a similarly high setting) be able to move this alleged wingbox section alone after the rest of the aircraft broke up?
http://www.pprune.org/5694361-post365.html
I'd appreciate it you would not copy-and-paste my previous post (#360) and use it as your own, complete with my observations. You do know how to quote text so please, whenever you agree with what someone else has written and/or linked to, quote them properly and then add whatever you want outside the quote-box!
PJ2
Thanks for the composite. I wanted to do something similar when I found the video last night but time (I needed to go to bed) did not allow me to :-(
Schubinho
I do not believe the markings are caused by the (main) landing gear. It more looks like the belly of the plane (your possibility #1) which simply slided some 200 meters until it encountered the road running north-west near the mosque and which appears to be slightly higher. If the main gear would have been down at initial impact, they would have been ripped off almost instantly or, posibly when they hit the aforementioned road, and thus be located within the vicinity of the tail-section.
Unfortunately, we do not know (at least not from the aerial shot I linked to as video stops there) if there is any more debris after what appears to be the wingbox (and which would be closer to the runway).
--
As others have already questioned, would a scenario where the pilots initiated a go around applying TOGA (and gear up) perhaps explain the lack of gear-tracks on the ground and the fact that the wings (though still unconfirmed these are actually the wings) appear some 730 meters from initial impact area? Would engines still running at TOGA (or a similarly high setting) be able to move this alleged wingbox section alone after the rest of the aircraft broke up?
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Ah well, although we are probably only hours away from FDR results of procedure flown, pitch, roll, yaw,.RPM, RadAlt, CVR transcript etc, I might as well join the speculation.
Are we certain there are no gear marks before the start of the pictures? Why would the gear be up? I would deduce that the 'furrows' seen at the start are dug by engine exhaust. Once the tail separated (presumably survivor seated here and ejected?) the pitch of full power would rapidly raise the nose, followed by a rapid nose down following a stall and an extremely hard final impact collapsing the forward section. How's that? Fits with the Alitalia visual too.
Are we certain there are no gear marks before the start of the pictures? Why would the gear be up? I would deduce that the 'furrows' seen at the start are dug by engine exhaust. Once the tail separated (presumably survivor seated here and ejected?) the pitch of full power would rapidly raise the nose, followed by a rapid nose down following a stall and an extremely hard final impact collapsing the forward section. How's that? Fits with the Alitalia visual too.
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Approach design
288' height from missed approach point to threshold is not a lot to decide and alter course when on a 4° offset course, or perform a safe go-around. At that missed approach point you are 80 m to the right of the extended centerline and 4° of course. The Jeppchart does not make immediately clear that you are on an offset course. It draws the visual approach course along the centerline.
For sure this approach design is to be legal (I am no specialist), but you can wonder how safe it is. 288' height is not a lot on an offset non-precision approach.
For sure this approach design is to be legal (I am no specialist), but you can wonder how safe it is. 288' height is not a lot on an offset non-precision approach.
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What's even more important, why was the aircraft off course, to the right?
Runway 09 at TIP is served by a very accurate NDB approach...two beacons as I recall.
A simple exercise...provided of course, the pilots were at a reasonable proficient level.
Could it be that pilots that are 'slaves to the magenta line' are so out of touch with everyday flying reality, that they lose track of just where they (and their aircraft) are?
Runway 09 at TIP is served by a very accurate NDB approach...two beacons as I recall.
A simple exercise...provided of course, the pilots were at a reasonable proficient level.
Could it be that pilots that are 'slaves to the magenta line' are so out of touch with everyday flying reality, that they lose track of just where they (and their aircraft) are?
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I estimate he was 2° off course to the right, provided he was following the 92° M course towards TPI on the VOR DME Rwy 09 approach.
Being 2° off course (which is not a lot on a VOR track so close to the VOR itself) can be explained by VOR deviation either at the VOR itself or in the aircraft, dialed in the wrong course, being off course due to wind, less precise flying, or flying 'visually' towards an imagined runway in less then optimal visibility.
Niner Mike.
Being 2° off course (which is not a lot on a VOR track so close to the VOR itself) can be explained by VOR deviation either at the VOR itself or in the aircraft, dialed in the wrong course, being off course due to wind, less precise flying, or flying 'visually' towards an imagined runway in less then optimal visibility.
Niner Mike.
Last edited by Niner_Mike; 15th May 2010 at 15:45.
BOAC;
By the evidence of its destruction, the gear was likely down; the main gear oleos are fragmented, tires are broken off and have lost their pressure.
(For others, if the aircraft was indeed on the approach to 09, the gear would have been down at this point, (normally extended between 1500' and 2500' or about 5 to 8km from the runway to stay within stabilized approach criteria).
I think once touchdown/impact had occurred as evidenced in the sand, engine power and/or control position and forces would have been largely ineffective. The engines would have swallowed a lot of sand and other debris; - the structure would be responding to variations in the terrain and the obstacles such as trees. Where the structure was in contact with the terrain, the drag offered by such contact would far outweigh any ability of the control surfaces to overcome. Once ground contact was made, the engines would have been inoperative.
As seen in an early video before they were moved to the highway, (where they are seen in the composite), the wing on the left in that early video is almost certainly upside down as evidenced by the spoiler panels seen on the bottom of the structure. I can't tell with the other wing but to me it looks correctly oriented, (top of the wing, up).
FWIW, I don't think the slightly-south track of the approach, being interpreted here as "off-course", has much to do with this accident.
RetiredF4, thanks again for the link to this video.
411A;
The Jepps show the two NDBs; the approach would have been straightforward, I agree.
That said, it all depends upon how the approach was being conducted and what was both available to the crew and what was used. I get the sense that this was an experienced, veteran crew although we do not yet know what experience they had on the A330, (the airplane was new but perhaps they had a background...we don't know).
The range of choices for the approach is a full, looking-outside visual to a fully-managed non-precision approach using the FMGEC and autoflight system.
The former (a visual) can be done close in as you know, even with a large aircraft and the requisite 'hands'; the latter, computer-based, autoflight-conducted approach requires more airspace (distance) to stabilize and do its LNAV/VNAV work properly.
An "early" descent (below FAF altitude before the FAF) cannot be ruled out either on a visual or using "Selected-selected", (which just means using heading/VS or track/FPA on the autopilot), especially if visibility was locally reduced. An early descent likely wouldn't occur using fully managed as both track and crossing altitudes are flown by the autoflight system. Requirements or restrictions on its use, and training and experience will be the focus here.
PJ2
By the evidence of its destruction, the gear was likely down; the main gear oleos are fragmented, tires are broken off and have lost their pressure.
(For others, if the aircraft was indeed on the approach to 09, the gear would have been down at this point, (normally extended between 1500' and 2500' or about 5 to 8km from the runway to stay within stabilized approach criteria).
I think once touchdown/impact had occurred as evidenced in the sand, engine power and/or control position and forces would have been largely ineffective. The engines would have swallowed a lot of sand and other debris; - the structure would be responding to variations in the terrain and the obstacles such as trees. Where the structure was in contact with the terrain, the drag offered by such contact would far outweigh any ability of the control surfaces to overcome. Once ground contact was made, the engines would have been inoperative.
As seen in an early video before they were moved to the highway, (where they are seen in the composite), the wing on the left in that early video is almost certainly upside down as evidenced by the spoiler panels seen on the bottom of the structure. I can't tell with the other wing but to me it looks correctly oriented, (top of the wing, up).
FWIW, I don't think the slightly-south track of the approach, being interpreted here as "off-course", has much to do with this accident.
RetiredF4, thanks again for the link to this video.
411A;
What's even more important, why was the aircraft off course, to the right?
Runway 09 at TIP is served by a very accurate NDB approach...two beacons as I recall.
A simple exercise...provided of course, the pilots were at a reasonable proficient level.
Runway 09 at TIP is served by a very accurate NDB approach...two beacons as I recall.
A simple exercise...provided of course, the pilots were at a reasonable proficient level.
That said, it all depends upon how the approach was being conducted and what was both available to the crew and what was used. I get the sense that this was an experienced, veteran crew although we do not yet know what experience they had on the A330, (the airplane was new but perhaps they had a background...we don't know).
The range of choices for the approach is a full, looking-outside visual to a fully-managed non-precision approach using the FMGEC and autoflight system.
The former (a visual) can be done close in as you know, even with a large aircraft and the requisite 'hands'; the latter, computer-based, autoflight-conducted approach requires more airspace (distance) to stabilize and do its LNAV/VNAV work properly.
An "early" descent (below FAF altitude before the FAF) cannot be ruled out either on a visual or using "Selected-selected", (which just means using heading/VS or track/FPA on the autopilot), especially if visibility was locally reduced. An early descent likely wouldn't occur using fully managed as both track and crossing altitudes are flown by the autoflight system. Requirements or restrictions on its use, and training and experience will be the focus here.
PJ2
Last edited by PJ2; 15th May 2010 at 15:52. Reason: clarifications, additions
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Originally Posted by PJ
I think once touchdown/impact had occurred as evidenced in the sand,
As 411 says, in particular there is a 'threshold' NDB (assuming it was working) and that would have been pointing well off to the left. All very strange. Certainly in 2km into a dawn rising sun on an offset approach the threshold NDB would feature high in my scan.
Anyway as I said, we will know soon enough.
If the aircraft hit tail first with gear up it might suggest an event similar to the Melbourne one where TOGA was not quite selected and the aircraft kept descending. Selected FPA -3.0 degrees with possibly MCT and gear retracting. Visual clues more difficult to pick up omission because of the sun/viz.