The drama should be titled as: "The sacrificed Lockerbie Victim 271" ! Abdelbaset al-Megrahi affirm solemnly in his 'final interview before death' "that he never met shopkeeper Gauci in Malta, who identified him alleged - and he have nothing to do with the Lockerbie Tragedy"! The "Malta spectacle" marked as: "The Lockerbie Bomber" - is a honour infringement against the fraudulently convicted, Abdelbaset Al Megrahi - and his family. ALLAHU AKBAR
by Edwin and Mahnaz Bollier, MEBO Ltd. Switzerland. Webpage: www.lockerbie.ch
"Pan Am 103 was delayed by 20 minutes when it left for New York, and had it departed on schedule, it would have exploded over the ocean, leaving no clues at all."
I think I'm just going to go weep in a corner now.
Well, the world is full of misunderstandings. This one is closer to the truth than most.
Montanaro got the essence right - that the timing, if freely presettable on an electronic timer, would be a risky choice as a (very likely) delay would have changed history.
It's a strange attitude, and I see it in numerous poorly-informed commentators.
The comment seems to be accepting that the bomb was triggered by a countdown timer, in that it states as apparent fact that if the plane had taken off earlier then it would have been out over the Atlantic when it exploded. However, if it was a barometric timer, it would have gone off 38 minutes after take-off irrespective of when the plane actually took off. That was kind of the point of the things.
So, if it was a Khreesat altimeter thing, it would have gone off over Lockerbie no matter how late or early the plane was.
If on the other hand it was a countdown timer there was no possibility at all that the plane could have reached the Atlantic. In fact the plane was on time. The best it could possibly have managed would have been maybe ten minutes earlier, if it had (improbably) got from the departure gate to the runway in only 15 minutes. That wouldn't have got it over the Atlantic, it would have got it over Glasgow.
And yes, this would suggest the terrorists were brain-dead, because the plane would only have had to have been 40 minutes late (on a stormy winter evening at Heathrow, not exactly unheard-of) for the thing to have gone off harmlessly on the tarmac. Whereas setting a countdown timer to go off four or five hours later would have been almost certain to have hit the open ocean (or maybe the uninhabited wilds of eastern Canada).
This is the real paradox of the disaster, and it's being completely obscured by all this ill-thought-out and ill-informed rubbish about the plane being late (which is wasn't) and it being over the Atlantic 20 minutes after passing Lockerbie (which it wouldn't have been anyway).
There was a Bombing (1988) on the airplane "PanAm 103" over Lockerbie, with 270 victims - and in addition to that, there's a "Lockerbie Affair" from A to Z.
Out of it were partly intentional various conspiracy theories created, to divert from the real background of the "Lockerbie Tragedy" - or to bring the case to another track ! +++ in german language:
Es gab ein Attentat (1988) auf das Flugzeug "PanAm 103" über Lockerbie, mit 270 Opfern - und ergänzend dazu, gibt es eine "Lockerbie-Affäre" von A - Z.
Daraus wurden zum Teil, vorsätzlich verschiedene konspirative Theorien kreiert, um von den wirklichen Hintergründen der "Lockerbie-Tragödie" abzulenken, oder den Fall auf eine andere Spur zubringen !
by Edwin and Mahnaz Bollier, MEBO Ltd. Telecommunication Switzerland. Webpage: www.lockerbie.ch
Attn. Rolfe: The aircraft "PanAm 103" - had to crash on the country, after logical reasoning necessarily ! +++ Das Flugzeug "PanAm 103" - musste nach logischer Überlegung unbedingt auf dem Land abstürzen.
And even if it went off harmlessly it would still have been hyped into a terrorist outrage worthy of a response that matched a response to a successful atrocity.
And yet there was no response and no enquiry, just a bogus investigation.
And even an unsuccessful atrocity is still a media coup for a terrorist group who can claim the ability to by-pass security and strike as a warning.
And yet there was no credible claim of responsibility.
And this is the telling point, because a terrorist group wants the political publicity for their actions, because in the scheme of things their physical attacks are harmless pin-pricks on the mighty West.
Oh, I think it was a Khreesat device, and would have exploded after 38 minutes regardless of the take-off time.
In the case of a Khreesat device, it would make no difference whether or not the plane was late. So why do so many people who SEEM to agree it was a Khreesat device make such a big deal about the plane allegedly being late? It's nonsensical.
The big myth about the plane being late actually supports the MST-13 theory. Of course it's a complete nonsense to imagine that anyone smart enough to walk and chew gum at the same time would have set an MST-13 so that it would go off harmlessly on the tarmac if the flight was delayed by as little as 45 minutes. And that would include anyone smart enough to smuggle a bomb on board KM180 at Malta without leaving any trace that this had been done at all. Especially someone whose day job was a flight dispatcher.
The "late plane" fairy-story purports to explain this. Of course Megrahi wasn't such an idiot as to set the timer for so early in the flight time. He set it correctly, intending the plane to disappear over the Atlantic. But the plane was late....
Those who look at the timings a bit more carefully realise there's something amiss with this. They know the plane was timetabled to push off from the gate at 18.00 and the wheels left the runway at 18.25. How late is that?
Not late, is the answer. That is on time. But the actor manages to squeeze this into "20 minutes late", as if any plane ever got airborne at Heathrow only 5 minutes after leaving the gate! A BBC documentary was more realistic, claiming ten minutes late - knowing that 15 minutes is the bare minimum for the gate-to-takeoff time. Then they looked at Lockerbie and tried to figure out where the plane would have been ten minutes later. The answer is Glasgow. However, so wedded were they to the notion of the intended mid-Atlantic disappearance, they decided the flight was actually going to take a sharp left immediately, and would have crossed the shoreline at Prestwick - nine minutes later. So the myth was allowed to persist, but now whittled down to a plane that would just have cleared the shore if it had been as sharp off the blocks as it was possible to be.
The plane was due to fly over Glasgow, and the western Highlands, and the southern tip of Skye, and Benbecula. It wasn't going to turn sharp left, and it wouldn't have been out over even the Minch for a good half-hour. It certainly wouldn't have been clear of land only 20 minutes after passing Lockerbie.
But it wasn't late. It was on time. The explosion makes perfect sense in the context of a Khreesat device, and none at all in the context of an MST-13. All this nonsense about it being late does nothing but defend the risible notion that a countdown timer was involved, and defends the indefensible case against Megrahi.
Hopefully the essense of your detailing will be read and understood.
1. IF an electronic timer was to be used, it would be an absurd choice to set the explosion so close to scheduled departure time. A delay of only 30 minutes (very likely, given the busy time of the year) would have had the bomb exploding on the ground, with minimal effect. 2. Interestingly, the time of explosion matches perfectly what would have been the result if a pressure gauge device had been used instead. 3. And such devices were known to be in use. 4. As a rather irrelevant facts: - the Panam 103 was actually on time, leaving for the runway close to 18:00 - setting a timer just half an hour later would not have assured that the plane would be over the ocean.
- - -
In fact, (2) is quite a bit of a coincidence.
But is it correct? I recall earlier discussions about this long time ago. Also something about delay in the gauges, as some airports may try to lower the pressure to trigger such devices.
Would you, with your knowledge, say that the altitude reached after half an hour of flying is a perfect match? And how much variation would be expected?
I sit with a feeling that then having a timer triggering near max altitude (which I would have thought would have been reached earlier) would be risky business. There is a tolerance in everything. You might risk that it didn't trigger at all.
Would it be more prudent to set the gauge to trigger in a height of, say, 3 kilometers?
Sorry if all this is an old discussion, which I missed out on, or just can't remember the details of.
- - -
Given (1)+(2)+(3) we have a enhanced support for a theory that a pressure gauge was used, and so against a timer-theory.
Of course it is not conclusive: Maybe the bombmaker a. a bit stupidly thought that one hour after departure time the plane would have to be in the air b. _preferred_ to have the plane crashing on land, where it might do additional damage.
But all in all - one more nail in the official theory.
SM, I need to explain again how these devices actually functioned.
First, while both Heathrow and Frankfurt had pressure chambers that could be used to screen suspect luggage for barometrically-triggered bombs, none of the luggage for PA103 was screened in that way.
Now, about the function. Bear in mind these devices were inside the plane, in the pressurised space. The barometer couldn't detect the outside pressure at cruising height, it detected the fall in pressure that occurs during the first few minutes of the flight. The fall from sea-level to the pressure maintained in-flight, which is equivalent to about 8,000 feet altitude.
This is all over within the first ten minutes, after which the flight-pressure stays level within the plane. So the barometer trigger had to trip within this period - in practice they were set at a level that would trip after about 7 minutes flight. 1970s devices exploded at that time. Several flights survived because this was still too low for explosive decompression.
To address this, and the pressure chambers, Khreesat added the time delay element. The barometer then triggered a capacitor to begin charging. When that was fully charged, it discharged, and triggered the bomb. Khreesat had a number of capacitors with different charging times - I think it was 20, 30 and 45 minutes. If the Lockerbie bomb was one of these, it was a 30-minute capacitor. 7 minutes or so to get to barometer trigger height, 30 minutes or so for the capacitor to charge (neither of these times was super-precise), gets Maid of the Seas to Lockerbie.
I had not understood about pressure in an airplane (cargo room. Now I wonder if it would be the same as in the passenger area?
- - -
For the importance of the inside-outside pressure difference for maximum damage - and for once Dave will agree to the significance of this - it is convenient that the plane has reached a high altitude. And so my suggested 3-4 kilometers would be a mistake.
Note, though, that it would be a mistake to say that the time of explosion "to the minutes" matched the use of pressure gauge.
Charging huge electrolyte capacitors through ditto huge resistances (needed for such long delays) comes with significant tolerances, maybe up to 25%. (I have played with that in my old days). This could surely be improved on (experiments and components), but for bombing-purposes, there would be no need for a better precision.
What is correct is, that the time of the explosion would fall nicely into what such a timer would have provided, while it would have been an extraordinarily risky choice if manually set on a digital timer.
- - -
Dear Dave,
in a lengthy report is it extremely likely that several things are wrong, imprecise, misunderstood etc. etc.
But this generic fact alone can not be used for anything in a serious debate.
For this reason: > So the AAIB report just got the make of IED wrong?
The entire aircraft is pressurised equally. It can't be otherwise, for engineering reasons. It works like a huge balloon, and you can't not pressurise part of a balloon, or have part at a different pressure from the rest.
You can see that in the way the plane disintegrated. Two things happened almost at once. The explosion blew a small hole in the fuselage which petalled out to become a bigger hole, and the overpressure caused by the explosive gases inside the plane caused the skin to rupture in places quite distant from the hole. So a whole chunk of the top peeled away, followed by a chunk from the bottom. That's why the break-up was so fast. Early Khreesat devices (without the capacitor) didn't cause that to happen because they exploded only about ten minutes after take-off and the pressure differential wasn't significant.
You're right about the time not being exact, but the fact is, it DID match it to the minute. Quite a lot of experiments were done with these capacitors, and the main variability was time since the last discharge. If they hadn't been through a charge-discharge cycle for some time, then the time elapsed was fairly constant. Certainly a lot closer than a 25% variation.
The time taken to reach the trigger height would also vary a little depending on just how quickly the plane climbed out of Heathrow. Theoretically you're looking at seven minutes plus 30 minutes, both numbers give or take, but in fact the actual time elapsed was 38 minutes. Which is actually correct to the minute. More correct than it really had to be, because as you say there could have been a fair window of possibility.
The AAIB made no finding about the make of the IED. Dave's ignorance about the evidence in the case has ceased to astonish me.
The one really suspect thing about the AAIB report is that it slips in the assertion that the floor of the baggage container appeared to have been protected by, "presumably, a piece of luggage". This to my mind is going beyond the remit of AAIB inspectors, who let's face it are not explosion experts. It amounts in effect to an assertion that the explosion was not in the bag on the floor of the container, that is, it was not the Bedford suitcase.
All that is entirely implicit, of course. You have to know about Bedford's evidence to see the significance, and of course the AAIB and indeed the RARDE scientists affected not to know anything about Bedford's evidence.
I really, really want to know why Peter Claiden included that statement in his April 1989 report on the baggage container. Someone was feeding him that line, I'm sure of it.
While it is compartmentalised, the compartments connect. The AAIB report has a number of diagrams with arrows showing the connections and how the overpressure was propagated within the structure. This was part of the recommendations in the report - how to prevent the overpressure having such a catastrophic effect on more distant parts of the aircraft.
In the case of Maid of the Seas, two things happened at once. The skin was punctured from the inside at one place, AND the balloon "burst" due to internal overpressure. This all happened well before the 3-second mark.
I'm not expecting you to be able to comprehend such a complex concept Dave, don't worry your little head about it.
The AAIB inspectors say the floor of the container was not marked by the explosion because the ‘bomb’ case was on top of another case that protected the floor!
Rolfe says the ‘bomb’ case was on the container floor, and the floor was not marked because some clothing in the ‘bomb’ case protected the container floor!
Both improbable, but the telling point is Rolfe thinks the AAIB inspectors are wrong because, “let’s face it they are not explosive experts”.
Also Rolfe says the AAIB report does not identify the make of IED, presumably because the AAIB inspectors are “not explosive experts” and therefore not qualified to say.
But surely explosive experts should be involved in an investigation into a bombing - and if not the AAIB report cannot blame a bomb because the AAIB inspectors “are not explosive experts”!
Dave, you have still failed to offer any explanation for the very clearly blast-damaged items that were recovered from the crash site, ample photographs of which are available.
If there was no blast, what is your explanation for these photographs? By what authority do you declare there was no blast?
presumably because the AAIB inspectors are “not explosive experts” and therefore not qualified to say.
There you go again, presuming and assuming.
The AAIB inspectors were not required to identify the IED because it wasn't their job. They didn't have the forensic evidence to make that determination. It's something that is simply not addressed in the report.
The forensic scientists, who did have that evidence, spent a long time trying to figure out the nature of the IED. This was a considerably more complex and protracted exercise than you seem to imagine. You will not find any of that information in the AAIB report.
Rolfe wrote: "You're right about the time not being exact, but the fact is, it DID match it to the minute. Quite a lot of experiments were done with these capacitors, and the main variability was time since the last discharge."
Strange, as it would be very trivial to ground the capacitor (of course through a reasonable resistor to limit current) if the state of the pressure gauge was high-pressure.
That way the device would have no 'memory', and only trigger when it had low-pressure status for the time it took to charge the capacitor from 0 to chosen trigger level.
But the relevant thing is of course if that was how it actually worked.
If the details were known, and experiments were made accordingly, you of course have a strong point.
I suddenly recall something about "ice-cube" timers being discussed here. I will google it.
- - -
Regarding the discussion whether the entire aircraft is always pressurized equally or not, this turned out to be quite difficult to determine with certainty.
What is clear is, that the luggage room has to be pressurized. Without pressure regulations troubles would come in many ways, including for Dave, who'd not even have cases of failing cargo doors to refer to! Also, live animals are transported there, and the leaking of shampoo bottles which can even be bad enough in hand luggage, would be a disastrous problem.
It was more difficult to determine if there could be a minor difference. It seems that there are valves that can be shut, in case of fires.
But all in all, it is hard to see any good reason why to accept the problems arising from a very large difference in pressure.
- - -
So I was wrong in assuming a continuously dropping pressure. I will make a note in my little book "List over my mistakes". (If anyone is surprised that it is a book and not just a file on my PC, the reason is, that when I needed to write something last time, computers hadn't made it into private homes yet.)
As you say, I don't think it was that important to them to have the time exact. But they themselves knew the variation and limitations of their devices. Khreesat himself did a lot of tests, and was quite forthcoming about it.
"Ice cube" is just jargon for the capacitor as far as I can make out.
I don't imagine the entire plane would be exactly at the same pressure, but variations would only be as the internal fittings interfered with the balloon. The pressurised part has to be a regular shape like a balloon or it doesn't work.
The barometers in these devices were set at an altitude high enough that it was very unlikely they would reach on land, but low enough to be sure that the thing would trigger if it was inside an aircraft taking off. I imagine they allowed enough wiggle-room for minor variations in cruising pressure.
(At one time I thought the cargo holds weren't pressurised, due to a repeatable accident with Irn Bru cans, and knowing about the bio-bottles that are mandatory for transport of lab specimens. However there must be a different explanation for the Irn Bru disasters - maybe the temperature drop? - and the bio-bottles are actually an insurance against explosive decompression in an air accident, not necessary for normal flight. I was put right about this some time ago on another forum. The hold that carries the pets has to be heated of course, which the normal cargo hold isn't.)
There is indeed quite a wide window within which a Khreesat device might explode. First there is the variation in reaching the trigger height, depending on exactly where that is set and how fast the plane climbs. Then there is the question of the actual time delay integral to the capacitor in use - 20, 30 or 45 minutes I think. Then there is the +/- on that depending on time since last discharge and so on. Anything from about 25 minutes to nearly an hour could be shoe-horned into that methodology if you really wanted to.
But in fact the numbers come out extraordinarily neat, at 7 or 8 minutes to get to trigger height, and 30 or 31 minutes for the 30-minute capacitor to charge/discharge.
MISSION LOCKERBIE, 2013 - (google translation, german/english):
ReplyDeleteThe drama should be titled as: "The sacrificed Lockerbie Victim 271" !
Abdelbaset al-Megrahi affirm solemnly in his 'final interview before death' "that he never met shopkeeper Gauci in Malta, who identified him alleged - and he have nothing to do with the Lockerbie Tragedy"!
The "Malta spectacle" marked as: "The Lockerbie Bomber" - is a honour infringement against the fraudulently convicted, Abdelbaset Al Megrahi - and his family. ALLAHU AKBAR
by Edwin and Mahnaz Bollier, MEBO Ltd. Switzerland. Webpage: www.lockerbie.ch
"Pan Am 103 was delayed by 20 minutes when it left for New York, and had it departed on schedule, it would have exploded over the ocean, leaving no clues at all."
ReplyDeleteI think I'm just going to go weep in a corner now.
Well, the world is full of misunderstandings.
ReplyDeleteThis one is closer to the truth than most.
Montanaro got the essence right - that the timing, if freely presettable on an electronic timer, would be a risky choice as a (very likely) delay would have changed history.
But Somebody[TM] should tell him, of course.
It's a strange attitude, and I see it in numerous poorly-informed commentators.
ReplyDeleteThe comment seems to be accepting that the bomb was triggered by a countdown timer, in that it states as apparent fact that if the plane had taken off earlier then it would have been out over the Atlantic when it exploded. However, if it was a barometric timer, it would have gone off 38 minutes after take-off irrespective of when the plane actually took off. That was kind of the point of the things.
So, if it was a Khreesat altimeter thing, it would have gone off over Lockerbie no matter how late or early the plane was.
If on the other hand it was a countdown timer there was no possibility at all that the plane could have reached the Atlantic. In fact the plane was on time. The best it could possibly have managed would have been maybe ten minutes earlier, if it had (improbably) got from the departure gate to the runway in only 15 minutes. That wouldn't have got it over the Atlantic, it would have got it over Glasgow.
And yes, this would suggest the terrorists were brain-dead, because the plane would only have had to have been 40 minutes late (on a stormy winter evening at Heathrow, not exactly unheard-of) for the thing to have gone off harmlessly on the tarmac. Whereas setting a countdown timer to go off four or five hours later would have been almost certain to have hit the open ocean (or maybe the uninhabited wilds of eastern Canada).
This is the real paradox of the disaster, and it's being completely obscured by all this ill-thought-out and ill-informed rubbish about the plane being late (which is wasn't) and it being over the Atlantic 20 minutes after passing Lockerbie (which it wouldn't have been anyway).
MISSION LOCKERBIE, 2013 - (google translation, german/english):
ReplyDeleteThere was a Bombing (1988) on the airplane "PanAm 103" over Lockerbie, with 270 victims - and in addition to that, there's a "Lockerbie Affair" from A to Z.
Out of it were partly intentional various conspiracy theories created, to divert from the real background of the "Lockerbie Tragedy" - or to bring the case to another track !
+++
in german language:
Es gab ein Attentat (1988) auf das Flugzeug "PanAm 103" über Lockerbie, mit 270 Opfern - und ergänzend dazu, gibt es eine "Lockerbie-Affäre" von A - Z.
Daraus wurden zum Teil, vorsätzlich verschiedene konspirative Theorien kreiert, um von den wirklichen Hintergründen der "Lockerbie-Tragödie" abzulenken, oder den Fall auf eine andere Spur zubringen !
by Edwin and Mahnaz Bollier, MEBO Ltd. Telecommunication Switzerland. Webpage: www.lockerbie.ch
Attn. Rolfe:
ReplyDeleteThe aircraft "PanAm 103" - had to crash on the country, after logical reasoning necessarily !
+++
Das Flugzeug "PanAm 103" - musste nach logischer Überlegung unbedingt auf dem Land abstürzen.
by Edwin Bollier, MEBO Ltd
And even if it went off harmlessly it would still have been hyped into a terrorist outrage worthy of a response that matched a response to a successful atrocity.
ReplyDeleteAnd yet there was no response and no enquiry, just a bogus investigation.
And even an unsuccessful atrocity is still a media coup for a terrorist group who can claim the ability to by-pass security and strike as a warning.
And yet there was no credible claim of responsibility.
And this is the telling point, because a terrorist group wants the political publicity for their actions, because in the scheme of things their physical attacks are harmless pin-pricks on the mighty West.
Oh, I think it was a Khreesat device, and would have exploded after 38 minutes regardless of the take-off time.
ReplyDeleteIn the case of a Khreesat device, it would make no difference whether or not the plane was late. So why do so many people who SEEM to agree it was a Khreesat device make such a big deal about the plane allegedly being late? It's nonsensical.
The big myth about the plane being late actually supports the MST-13 theory. Of course it's a complete nonsense to imagine that anyone smart enough to walk and chew gum at the same time would have set an MST-13 so that it would go off harmlessly on the tarmac if the flight was delayed by as little as 45 minutes. And that would include anyone smart enough to smuggle a bomb on board KM180 at Malta without leaving any trace that this had been done at all. Especially someone whose day job was a flight dispatcher.
The "late plane" fairy-story purports to explain this. Of course Megrahi wasn't such an idiot as to set the timer for so early in the flight time. He set it correctly, intending the plane to disappear over the Atlantic. But the plane was late....
Those who look at the timings a bit more carefully realise there's something amiss with this. They know the plane was timetabled to push off from the gate at 18.00 and the wheels left the runway at 18.25. How late is that?
Not late, is the answer. That is on time. But the actor manages to squeeze this into "20 minutes late", as if any plane ever got airborne at Heathrow only 5 minutes after leaving the gate! A BBC documentary was more realistic, claiming ten minutes late - knowing that 15 minutes is the bare minimum for the gate-to-takeoff time. Then they looked at Lockerbie and tried to figure out where the plane would have been ten minutes later. The answer is Glasgow. However, so wedded were they to the notion of the intended mid-Atlantic disappearance, they decided the flight was actually going to take a sharp left immediately, and would have crossed the shoreline at Prestwick - nine minutes later. So the myth was allowed to persist, but now whittled down to a plane that would just have cleared the shore if it had been as sharp off the blocks as it was possible to be.
The plane was due to fly over Glasgow, and the western Highlands, and the southern tip of Skye, and Benbecula. It wasn't going to turn sharp left, and it wouldn't have been out over even the Minch for a good half-hour. It certainly wouldn't have been clear of land only 20 minutes after passing Lockerbie.
But it wasn't late. It was on time. The explosion makes perfect sense in the context of a Khreesat device, and none at all in the context of an MST-13. All this nonsense about it being late does nothing but defend the risible notion that a countdown timer was involved, and defends the indefensible case against Megrahi.
I wish people would stop doing it.
Now I finally understand it.
ReplyDeleteYou are saying, that it was really the timer clock that was behind, right?
Just kidding!
ReplyDeleteHopefully the essense of your detailing will be read and understood.
1. IF an electronic timer was to be used, it would be an absurd choice to set the explosion so close to scheduled departure time.
A delay of only 30 minutes (very likely, given the busy time of the year) would have had the bomb exploding on the ground, with minimal effect.
2. Interestingly, the time of explosion matches perfectly what would have been the result if a pressure gauge device had been used instead.
3. And such devices were known to be in use.
4. As a rather irrelevant facts:
- the Panam 103 was actually on time, leaving for the runway close to 18:00
- setting a timer just half an hour later would not have assured that the plane would be over the ocean.
- - -
In fact, (2) is quite a bit of a coincidence.
But is it correct?
I recall earlier discussions about this long time ago.
Also something about delay in the gauges, as some airports may try to lower the pressure to trigger such devices.
Would you, with your knowledge, say that the altitude reached after half an hour of flying is a perfect match?
And how much variation would be expected?
I sit with a feeling that then having a timer triggering near max altitude (which I would have thought would have been reached earlier)
would be risky business. There is a tolerance in everything. You might risk that it didn't trigger at all.
Would it be more prudent to set the gauge to trigger in a height of, say, 3 kilometers?
Sorry if all this is an old discussion, which I missed out on, or just can't remember the details of.
- - -
Given (1)+(2)+(3) we have a enhanced support for a theory that a pressure gauge was used, and so against a timer-theory.
Of course it is not conclusive:
Maybe the bombmaker
a. a bit stupidly thought that one hour after departure time the plane would have to be in the air
b. _preferred_ to have the plane crashing on land, where it might do additional damage.
But all in all - one more nail in the official theory.
SM, I need to explain again how these devices actually functioned.
ReplyDeleteFirst, while both Heathrow and Frankfurt had pressure chambers that could be used to screen suspect luggage for barometrically-triggered bombs, none of the luggage for PA103 was screened in that way.
Now, about the function. Bear in mind these devices were inside the plane, in the pressurised space. The barometer couldn't detect the outside pressure at cruising height, it detected the fall in pressure that occurs during the first few minutes of the flight. The fall from sea-level to the pressure maintained in-flight, which is equivalent to about 8,000 feet altitude.
This is all over within the first ten minutes, after which the flight-pressure stays level within the plane. So the barometer trigger had to trip within this period - in practice they were set at a level that would trip after about 7 minutes flight. 1970s devices exploded at that time. Several flights survived because this was still too low for explosive decompression.
To address this, and the pressure chambers, Khreesat added the time delay element. The barometer then triggered a capacitor to begin charging. When that was fully charged, it discharged, and triggered the bomb. Khreesat had a number of capacitors with different charging times - I think it was 20, 30 and 45 minutes. If the Lockerbie bomb was one of these, it was a 30-minute capacitor. 7 minutes or so to get to barometer trigger height, 30 minutes or so for the capacitor to charge (neither of these times was super-precise), gets Maid of the Seas to Lockerbie.
So the AAIB report just got the make of IED wrong?
ReplyDeleteDear Rolfe,
ReplyDeletethank you for the explanation.
I had not understood about pressure in an airplane (cargo room.
Now I wonder if it would be the same as in the passenger area?
- - -
For the importance of the inside-outside pressure difference for maximum damage - and for once Dave will agree to the significance of this - it is convenient that the plane has reached a high altitude. And so my suggested 3-4 kilometers would be a mistake.
Note, though, that it would be a mistake to say that the time of explosion "to the minutes" matched the use of pressure gauge.
Charging huge electrolyte capacitors through ditto huge resistances (needed for such long delays) comes with significant tolerances, maybe up to 25%. (I have played with that in my old days).
This could surely be improved on (experiments and components), but for bombing-purposes, there would be no need for a better precision.
What is correct is, that the time of the explosion would fall nicely into what such a timer would have provided, while it would have been an extraordinarily risky choice if manually set on a digital timer.
- - -
Dear Dave,
in a lengthy report is it extremely likely that several things are wrong, imprecise, misunderstood etc. etc.
But this generic fact alone can not be used for anything in a serious debate.
For this reason:
> So the AAIB report just got the make of IED wrong?
is a unconstructive trick-like question.
The entire aircraft is pressurised equally. It can't be otherwise, for engineering reasons. It works like a huge balloon, and you can't not pressurise part of a balloon, or have part at a different pressure from the rest.
ReplyDeleteYou can see that in the way the plane disintegrated. Two things happened almost at once. The explosion blew a small hole in the fuselage which petalled out to become a bigger hole, and the overpressure caused by the explosive gases inside the plane caused the skin to rupture in places quite distant from the hole. So a whole chunk of the top peeled away, followed by a chunk from the bottom. That's why the break-up was so fast. Early Khreesat devices (without the capacitor) didn't cause that to happen because they exploded only about ten minutes after take-off and the pressure differential wasn't significant.
You're right about the time not being exact, but the fact is, it DID match it to the minute. Quite a lot of experiments were done with these capacitors, and the main variability was time since the last discharge. If they hadn't been through a charge-discharge cycle for some time, then the time elapsed was fairly constant. Certainly a lot closer than a 25% variation.
The time taken to reach the trigger height would also vary a little depending on just how quickly the plane climbed out of Heathrow. Theoretically you're looking at seven minutes plus 30 minutes, both numbers give or take, but in fact the actual time elapsed was 38 minutes. Which is actually correct to the minute. More correct than it really had to be, because as you say there could have been a fair window of possibility.
The AAIB made no finding about the make of the IED. Dave's ignorance about the evidence in the case has ceased to astonish me.
The one really suspect thing about the AAIB report is that it slips in the assertion that the floor of the baggage container appeared to have been protected by, "presumably, a piece of luggage". This to my mind is going beyond the remit of AAIB inspectors, who let's face it are not explosion experts. It amounts in effect to an assertion that the explosion was not in the bag on the floor of the container, that is, it was not the Bedford suitcase.
All that is entirely implicit, of course. You have to know about Bedford's evidence to see the significance, and of course the AAIB and indeed the RARDE scientists affected not to know anything about Bedford's evidence.
I really, really want to know why Peter Claiden included that statement in his April 1989 report on the baggage container. Someone was feeding him that line, I'm sure of it.
Unlike a balloon a passenger airliner is compartmentalized and will not be uniformly affected by a puncture.
ReplyDeleteIndeed the balloon analogy is wrong because the balloon implodes at the point of puncture, it doesn’t burst to pieces everywhere.
Rolfe says it would to explain the false simulation sequence that inspired her new book cover.
The fact is the cockpit detached in 3 seconds knocking off engine 3 and other parts detached later during the break-up phase.
While it is compartmentalised, the compartments connect. The AAIB report has a number of diagrams with arrows showing the connections and how the overpressure was propagated within the structure. This was part of the recommendations in the report - how to prevent the overpressure having such a catastrophic effect on more distant parts of the aircraft.
ReplyDeleteIn the case of Maid of the Seas, two things happened at once. The skin was punctured from the inside at one place, AND the balloon "burst" due to internal overpressure. This all happened well before the 3-second mark.
I'm not expecting you to be able to comprehend such a complex concept Dave, don't worry your little head about it.
The AAIB inspectors say the floor of the container was not marked by the explosion because the ‘bomb’ case was on top of another case that protected the floor!
ReplyDeleteRolfe says the ‘bomb’ case was on the container floor, and the floor was not marked because some clothing in the ‘bomb’ case protected the container floor!
Both improbable, but the telling point is Rolfe thinks the AAIB inspectors are wrong because, “let’s face it they are not explosive experts”.
Also Rolfe says the AAIB report does not identify the make of IED, presumably because the AAIB inspectors are “not explosive experts” and therefore not qualified to say.
But surely explosive experts should be involved in an investigation into a bombing - and if not the AAIB report cannot blame a bomb because the AAIB inspectors “are not explosive experts”!
So on whose authority is Rolfe blaming a ‘bomb’?
On the authority of all the photographs of the bits that WERE damaged by the explosive blast.
ReplyDeleteYou could try looking at them some time.
Oh so your the expert?
ReplyDeleteDave, you have still failed to offer any explanation for the very clearly blast-damaged items that were recovered from the crash site, ample photographs of which are available.
ReplyDeleteIf there was no blast, what is your explanation for these photographs? By what authority do you declare there was no blast?
presumably because the AAIB inspectors are “not explosive experts” and therefore not qualified to say.
ReplyDeleteThere you go again, presuming and assuming.
The AAIB inspectors were not required to identify the IED because it wasn't their job. They didn't have the forensic evidence to make that determination. It's something that is simply not addressed in the report.
The forensic scientists, who did have that evidence, spent a long time trying to figure out the nature of the IED. This was a considerably more complex and protracted exercise than you seem to imagine. You will not find any of that information in the AAIB report.
Rolfe wrote:
ReplyDelete"You're right about the time not being exact, but the fact is, it DID match it to the minute. Quite a lot of experiments were done with these capacitors, and the main variability was time since the last discharge."
Strange, as it would be very trivial to ground the capacitor (of course through a reasonable resistor to limit current) if the state of the pressure gauge was high-pressure.
That way the device would have no 'memory', and only trigger when it had low-pressure status for the time it took to charge the capacitor from 0 to chosen trigger level.
But the relevant thing is of course if that was how it actually worked.
If the details were known, and experiments were made accordingly, you of course have a strong point.
I suddenly recall something about "ice-cube" timers being discussed here. I will google it.
- - -
Regarding the discussion whether
the entire aircraft is always pressurized equally or not, this turned out to be quite difficult to determine with certainty.
What is clear is, that the luggage room has to be pressurized. Without pressure regulations troubles would come in many ways, including for Dave, who'd not even have cases of failing cargo doors to refer to!
Also, live animals are transported there, and the leaking of shampoo bottles which can even be bad enough in hand luggage, would be a disastrous problem.
It was more difficult to determine if there could be a minor difference. It seems that there are valves that can be shut, in case of fires.
But all in all, it is hard to see any good reason why to accept the problems arising from a very large difference in pressure.
- - -
So I was wrong in assuming a continuously dropping pressure. I will make a note in my little book "List over my mistakes". (If anyone is surprised that it is a book and not just a file on my PC, the reason is, that when I needed to write something last time, computers hadn't made it into private homes yet.)
As you say, I don't think it was that important to them to have the time exact. But they themselves knew the variation and limitations of their devices. Khreesat himself did a lot of tests, and was quite forthcoming about it.
ReplyDelete"Ice cube" is just jargon for the capacitor as far as I can make out.
I don't imagine the entire plane would be exactly at the same pressure, but variations would only be as the internal fittings interfered with the balloon. The pressurised part has to be a regular shape like a balloon or it doesn't work.
The barometers in these devices were set at an altitude high enough that it was very unlikely they would reach on land, but low enough to be sure that the thing would trigger if it was inside an aircraft taking off. I imagine they allowed enough wiggle-room for minor variations in cruising pressure.
(At one time I thought the cargo holds weren't pressurised, due to a repeatable accident with Irn Bru cans, and knowing about the bio-bottles that are mandatory for transport of lab specimens. However there must be a different explanation for the Irn Bru disasters - maybe the temperature drop? - and the bio-bottles are actually an insurance against explosive decompression in an air accident, not necessary for normal flight. I was put right about this some time ago on another forum. The hold that carries the pets has to be heated of course, which the normal cargo hold isn't.)
There is indeed quite a wide window within which a Khreesat device might explode. First there is the variation in reaching the trigger height, depending on exactly where that is set and how fast the plane climbs. Then there is the question of the actual time delay integral to the capacitor in use - 20, 30 or 45 minutes I think. Then there is the +/- on that depending on time since last discharge and so on. Anything from about 25 minutes to nearly an hour could be shoe-horned into that methodology if you really wanted to.
But in fact the numbers come out extraordinarily neat, at 7 or 8 minutes to get to trigger height, and 30 or 31 minutes for the 30-minute capacitor to charge/discharge.
Rolfe dissembles by agreeing aircraft are compartmentalized but adding “they are all connected”, implying same as a balloon!
ReplyDeleteEr Yes but No, because they are connected by doors than remain shut during flight.
Read section 1.6.3 of the AAIB report. Looks pretty well interconnected to me.
ReplyDelete