Talk:Uncontrolled decompression

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Someone with some free time should sort through Geoffrey Landis' site (in external links) and post the information here.

Paul Withey's Statement[edit]

Explosive decompression is like a 500 lb bomb? I'm not sure what Paul Withey meant, but I believe it is total nonsense. A 500 lb bomb is more than enough to instantly pulverise the entire aircraft (consider that a sidewinder missile has a ~20 lb warhead). Didn't someone say 85% of statistics are made up on the spot? :p - January 2010 —Preceding unsigned comment added by 114.76.44.47 (talk) 12:21, 24 January 2010 (UTC)

I watched the Seconds from Disaster episode in which he makes that statement and I believe he was referrng not to explosive decompressions in general, but to that of BOAC Flight 781, which I removed from this article, and which WAS pulverized. Maybe we should delete the comment from here and put it on the BOAC Flight 781 article. --Whoop whoop pull up (talk) 23:16, 4 October 2010 (UTC)

eyes[edit]

This article doesn't talk about the eyes, but wouldn't people's eyeballs pop out if exposed to a total vaccum (at least if you didn't close your eyes really tight)?

  • Contry to popular belief, there is no way for the eyeball to "pop out", they are anchored very securely by six strong muscles, and nothing, not sneezing, nor Explosive decompression can force them out. Explosive decompression can however cause a sub-conjunctival bulla (a blister in the tissue of the eye) as in the Byford Dolphin accident, or, one would assume, the eye to burst.125.238.77.75 15:46, 24 May 2007 (UTC)

How about avulsion of the eyeball; though I don't think it could be caused by decompression, seems to be an impact sort of trauma. Pjbflynn 21:49, 2 July 2007 (UTC)

Popcorn?[edit]

Isn't popcorn create by this very same process?--Metron4 19:41, 1 May 2007 (UTC)

Sort of. But baloons are the most common example of explosive decompression, and are not mentioned at all. I shall be editing that.. Shadowedmist 21:35, 19 June 2007 (UTC)

Explosive vs rapid decompression[edit]

Yes, there is a difference see Google Books Socrates2008 (Talk) 12:55, 28 July 2008 (UTC)

Just to defend myself against the untrue claims of vandalism that have been placed in the edit summaries and elsewhere, the edits I have made were a deliberate good faith comprimise edit to try to find a common ground between the two views. Ultimately, the list of aircraft incidents (a section I renamed to encompass both names) are just a list of related links - each and every one of those entries should have categorisation one way or another in their own articles and should also be fully referenced in their own articles (or have fact templates inserted if required), so there is no loss of information from Wikipedia. In fact, in the context of this page, different references that have been cited contradict each other, with some clearly indicating that United Airlines Flight 811 would not have been an explosive decompression due to the volume of the vessel. In contrast, on it's own article, the position stated in the NTSB report is effectively absolute and not really open to such challenge by Wikipedia standards. Collapsing the related links into a list of "Rapid and Explosive Decompression" events resolves this conflict of definitions. Leaving it as is devalues Wikipedia.
It should be remembered that rapid decompression is a redirect to this page, which covers both definitions and in fact looking through the edit history of the page, it looks like other editors have dealt with the definition problem by removing a number of links from the article, including United Airlines Flight 811, for the same reasons as I've outlined. My compromise edit has the beneficial side effect that those links can be reintroduced to this page, allowing readers to pursue further information and gain a deeper understanding of the topic. -- Rob.au (talk) 10:28, 29 July 2008 (UTC)
Glad to finally see some discussion on this page. There is a large body of reliable material (from organisations such as the FAA) that distinguishes between Explosive, Rapid and Slow decompression. Contrary to the note above, this article would benefit from a clear explanation and distinction between these related, yet different types of events, which are frequently confused by lay people. Given the clear distinctions in the three types of events, there is absolutely no reason why the examples should not follow the same pattern, otherwise they would simply be misleading or confusing. If there are article links other than QF30 that have issues, then these should be addressed too, rather than this article being watered down and blurred in order to make a controversial link such as QF30 work here. The fact that "rapid decompression" redirects to here is not this article's fault; however I can see benefit in all three concepts being covered by a single article, so have started to update it in that way.
There is currently a lot of lay speculation in the press and here on Wikipedia about the QF30 decompression incident, which I believe has triggered this dispute. My first reaction to the addition of QF30 to this article about explosive decompression, prior to any communication or finding being published by the ATSB, is that such a conclusion would consitute original research at worst or be unreliable at best, so I reverted it. The most recent press release from the ATSB has proved my concerns to be correct, as they have classified it as a rapid decompression event. I suspect Rob.au is perhaps taking this personally, and therefore is attempting to blur the lines between explosive decompression and rapid decompression in order to keep the QF30 rapid decompression link he added in the article. Certainly, tagging this article as unreferenced original research when it has references, as well as removing sub-headings is not adding any value, and in my view, therefore vandalism. Socrates2008 (Talk) 11:13, 29 July 2008 (UTC)
Please refer to WP:VANDALISM before continuing to make such inaccurate comments. Please also refer to WP:CIVIL ("referring to other editor's good faith edits as vandalism") and WP:ATTACK ("Comment on content, not on the contributor"), which I feel your comments are infringing. I have no argument at all with the new expansion of this page to include clearer definition of the terms - quite the contrary - you have improved the article by adding them. However this expension only backs up the point I made in my comment above - it continues to deepend the contradictions between the verifiable distinctions between what constitutes explosive and rapid decompression and the way various incidents have been identified even at official levels. I now even more strongly feel the the related links should remain only as related links and the identification of each being a rapid or explosive decompression should be the domain of the respective articles. -- Rob.au (talk) 12:14, 29 July 2008 (UTC)
I've fixed AA96 to Rapid decompression as per its report. Regarding TK981, you get the interesting situation that it was an incident that was basically much the same circumstance as the AA incident, as per the report findings. The official report[1], in French, calls it a "depressurisation brutale", which doesn't really quite translate neatly as either rapid or explosive, but of most interest is that it uses this same terminology to discuss the findings of AA96 that had been provided to them by the NTSB, those findings being a rapid decompression. This continues the inconsistancy and contradiction that has been unnecessarily introduced to this article. -- Rob.au (talk) 18:13, 29 July 2008 (UTC)

Requested move[edit]

I suggest this page is renamed to Uncontrolled decompression to account for the expansion (sic) in its scope to include rapid decompression and gradual decompression. Socrates2008 (Talk) 22:11, 29 July 2008 (UTC)

KAL 007[edit]

I changed rapid decompression to gradual decompression. From missile explosion to warning sound in CVR there was a span of 11 seconds (ICAO '93). Pilots heard speaking through mikes in Oxygen masks.Bert Schlossberg (talk) 12:21, 5 September 2008 (UTC)

Reverting your change as it appears to be OR, contradicting the Korean Air Lines Flight 007 article, as well as a number of sources. Socrates2008 (Talk) 14:28, 5 September 2008 (UTC)

From the article itself and the source in ICAO /93

18:26:13 GMT – Cabin Altitude Warning Alarm sounds indicating decompression due to missile shrapnel puncturing cabin. The fact that it sounded (CVR) 11 seconds after missile detonation indicates that total area of rupture damage to cabin is 1 3/4 square feet.[26]

ICAO Report 1993, p. 54. “Eleven seconds after the CAM recorded the first sounds of the attack, the sound of the cabin altitude warning was heard... It was possible to estimate the approximate area of holes which would result in a decompression and subsequent cabin altitude warning after eleven seconds. An estimate, taking into account the output of the air-conditioning packs, indicated holes with a total area in the order of 1.75 square feet.”

Also from article - "Two expert witnesses testified at a Court of Appeals trial on the issue of pre-death pain and suffering. Captain James McIntyre, an experienced Boeing 747 pilot and aircraft accident investigator, testified that Flight 007's tail was struck by shrapnel from a proximity missile. This shrapnel probably caused a hole smaller than two feet in diameter, resulting in decompression but leaving the passengers sufficient time to don oxygen masks. 'McIntyre testified that, based upon his estimate of the extent of damage the aircraft sustained, all passengers survived the initial impact of the shrapnel from the missile explosion. In McIntyre's expert opinion, at least twelve minutes elapsed between the impact of the shrapnel and the crash of the plane, and the passengers remained conscious throughout." [50]'

Bert Schlossberg (talk) 15:51, 5 September 2008 (UTC)

Unfortunately the problem is that you are drawing your own conclusions here based on your own interpretation of primary evidence. (For example, you've made an assumption above that the 12 minutes of flight before the aircraft crashed indicates how long the decompression event took, as well as not taking into account Time of Useful Consciousness) "Rapid decompression" is specifically mentioned in these books - these references meet the Wikipedia requirement for verifiability. Socrates2008 (Talk) 21:46, 5 September 2008 (UTC)

It took 11 seconds from the time the that the CAM recorder picked up the sound of detonation until the CAM recorder picked up the sound of the Alert signalling decompression. On this basis ICAO concluded that the extent of rupture to the cabin was 1 3/4 square feet. First Officer Son reports to Capt. Chun at 18:26:57, 55 seconds after detonation and the start of decompression: "Tokyo Radio, Korean Air Zero Zero Seven" and so on. ICAO concludes that his transmission then was through the mike in his oxygen mask. Masks had been deployed in the cabin before this with annoucements being heard through CVR. This was all within the "one minute of useful consiousmess".

Furthermore, two expert witnesses testified at a Court of Appeals trial on the issue of pre-death pain and suffering. Captain James McIntyre, an experienced Boeing 747 pilot and aircraft accident investigator, testified that Flight 007's tail was struck by shrapnel from a proximity missile. This shrapnel probably caused a hole smaller than two feet in diameter, resulting in decompression but leaving the passengers sufficient time to don oxygen masks. "McIntyre testified that, based upon his estimate of the extent of damage the aircraft sustained, all passengers survived the initial impact of the shrapnel from the missile explosion. In McIntyre's expert opinion, at least twelve minutes elapsed between the impact of the shrapnel and the crash of the plane, and the passengers remained conscious throughout." [50]

Does all this fit under "rapid decompression"?Bert Schlossberg (talk) 09:57, 6 September 2008 (UTC)

That's not for you or me or any other Wikipedia editor to judge ourselves. The way Wikipedia works, we're supposed to find conclusions reached by experts/third parties, then quote them here. Right now, we have multiple references stating "rapid decompression". Socrates2008 (Talk) 10:06, 6 September 2008 (UTC)

Got it! Must have missed something. Can you supply me the expert/third party references that consider the decompression of KAL 007 as "rapid"?Bert Schlossberg (talk) 10:45, 6 September 2008 (UTC)

Notable decompression accidents and incidents[edit]

Air France Flight AF447 should not be mentioned in this section before : 1. It is confirmed that decompression phenomen is linked in anyway with this tragedy 2. the "?" sign in the frame can be replaced by any explaination, as the purpose of Wikipedia "the free encyclopedia" is to teach, explain, let know and not to give extrapolation or fantasy. Yamqui (talk) 11:03, 3 June 2009 (UTC)

Agree 100% Socrates2008 (Talk) 13:02, 3 June 2009 (UTC)
Agree, far too early. Ex nihil (talk) 10:58, 4 June 2009 (UTC)

Removed AF447 for time being as at this point nobody has any idea of the cause. Parked the text below in case it gets recycled. | Air France Flight 447 | 2009 | Airbus A330-203 | Incident | 228/228 | ? | Unknown Ex nihil (talk) 11:02, 4 June 2009 (UTC)

Well, CNN now reports: "A large number of bodies also had red lesions in their mucous membranes, which the paper said is usually associated with asphyxia, or lack of oxygen." as well as "A major Brazilian newspaper reported this week that 95 percent of the bodies so far had shown fractures in the legs, arms and hips similar to injuries found in people who fall from great heights. The newspaper O Estado de Sao Paulo cited unnamed officials who are part of the investigation." Which leads to: "All of that, aviation experts have said, points to a mid-air rupture of the plane at about 35,000 feet." So, unless these unfortunates decided to en masse take up skydiving without parachutes, one can probably conclude that there was some sort of "decompression phenomenon" involved in this sad incident. Here is the link: http://edition.cnn.com/2009/WORLD/europe/06/19/france.brazil.crash/ Jmdeur (talk) 19:18, 19 June 2009 (UTC)
First: Still much too early, all conjecture and for some time to come I think. CNN is not an aircraft accident authority, if Airbus doesn't know then neither do we. Second: No indication that cabin pressurisation is causal here, rather just an inevitable downstream consequence of the airframe breaking up, which in turn was caused by something else upstream. The Comet I examples are there because cabin pressurisation was directly implicated but if the Comet airframes had disintegrated because of, say, aerodynamic overstressing it is not a cabin depressurisation incident; even though depressurisation is an inevitable consequence as the cabin disintegrates it would be a secondary effect not a primary cause. Otherwise, we would have to put every catastrophic pressurised airliner airframe failure in this list, which would not be helpful. Ex nihil (talk) 23:18, 19 June 2009 (UTC)

explosive decompression or something else[edit]

Was Aloha_Airlines_Flight_243 due to the decompression or the effects of high velocity wind on the failed section of the aircraft? That is, would the failure have been as spectacular if the same event (cabin vs atmospheric pressure) had occurred while the aircraft was at rest? I think not.... —Preceding unsigned comment added by 65.127.188.10 (talk) 22:34, 7 August 2009 (UTC)

I've added a couple of extended calculations and analyses by a pressure engineer and a corrosion engineer to assist with understanding the Aloha incident. The NTSB as an organization took the view that going beyond the corroded rivets (which implied rapid but not explosive decompression) was beyond its remit; but its lead investigator likes the 'fluid hammer' theory originating with Matt Austin a decade ago, which still attracts interest because it also accounts for a couple of other aircraft accidents. A Pakistani engineer recently looked into airstream impact through the stewardess' body, which would also have created a large stress spike; he comments of the fluid hammer hypothesis that the calculation involves ideal gas theory which doesn't well describe conditions at speed and altitude. Examining his paper closely shows he has only included the first part of Austin's calculation which indeed uses the ideal gas approximation, and not the subsequent fluid hammer.--Sdoradus (talk) 10:11, 27 June 2011 (UTC)

Missing Events[edit]

The loss of BEA 706, a Vickers Vanguard, G-APEC, over Aarsele, Belgium, was due to the rupture of the rear bulkhead and subsequent explosive decompression into the tail cone and stabilizers causing the destruction of same.Mark Lincoln (talk) 21:27, 5 May 2010 (UTC)

I agree that there are numerous aviation accidents that were caused by, or associated with, uncontrolled decompression. The example of the Vickers Vanguard that you gave is one of them. Another one is the most lethal single-aircraft accident that has ever occurred – Boeing 747 Japan Airlines Flight 123.
However, these accidents involved impact with the ground, causing immediate death of all on board. The focus of this article is decompression and its physiological effects on the occupants of the aircraft. For example, see Uncontrolled decompression#Decompression injuries. This focusses on the incapacitation and injuries that can occur following decompression, not the injuries that can occur when an aircraft impacts the ground at very high speed as the result of extreme structural damage.
For this reason, if the Vickers Vanguard and JAL 123 accidents are to be included in this article it must be in a new section that focuses on explosive decompression causing severe damage to the primary structure of the aircraft, rather than decompression having a physiological effect on the occupants. Dolphin (t) 22:57, 5 May 2010 (UTC)

Explosive decompression: contradiction between reality and theory[edit]

The article defines Explosive decompression thus:

"Explosive decompression occurs at a rate swifter than that at which air can escape from the lungs, typically in less than 0.1 to 0.5 seconds. The risk of lung trauma is very high..."

Then, the article goes on to say that the National Airlines Flight 27 accident in 1973, was a case of an "Explosive decompression" accident.

And, further down the chart it says that United Airlines Flight 811, in 1989 was also an example of an explosive decompression accident.

Thus, when I went to the official NTSB accident reports on those two accidents, I was expecting to find hordes of passengers and crew that suffered lung trauma.

Au contraire!

The report for the NAL DC-10 decompression accident does not even use the phrase "explosive decompression." It states that of the 123 souls on board, only 24 had to be treated for injuries, consisting of smoke inhalation (10), ear barotrauma problems (10) and minor abrasions (from going down the slides). No mention of any lung trauma suffered by anyone. Of course, one passenger was killed, but that had more to do with gravity, than with lung trauma...

The report for the UAL 811 accident does say it was a case of "explosive decompression," but as to injuries to the surviving 346 souls on board (nine more were ejected from the plane), there is no mention of lung trauma. Indeed, the word "lung" is not found anywhere in the report. As to injuries, it says of those 346 survivors:

"Most of the injuries sustained by the survivors were caused by the events associated with the decompression, such as baro-trauma to ears, and cuts and abrasions from the flying debris in the cabin. Other injuries were incurred during the emergency evacuation."

My point should be rather obvious by now. If it is true that "The risk of lung trauma is very high..." in explosive decompression accidents, then that truth should have been reflected by way of numerous lung trauma injuries to the total of 478 souls on board both accident aircraft. Yet, no one, not one, nada, suffered any kind of lung injury, according to the NTSB.

Something is either wrong with that FAA definition of explosive decompression, or else those two accidents were not valid examples of explosive decompression. Right now, the credibility of Wikipedia is on the line, with this issue. Something has to be changed in the article to rectify the obvious contradictions. 66.81.52.34 (talk) 09:26, 24 October 2011 (UTC)

Either that or everyone was lucky. Whoop whoop pull up Bitching Betty | Averted crashes 10:17, 24 October 2011 (UTC)