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Engr 321 Homework Set 5 Vanguard

an unplanned drop in the pressure of a sealed systemUncontrolled decompression is an unplanned drop in the pressure of a sealed system, such as an aircraft cabin or hyperbaric chamber, and typically results from human error, material fatigue, engineering failure, or impact, causing a pressure vessel to vent into its lower-pressure surroundings or fail to pressurize at all.

Such decompression may be classed as Explosive, Rapid, or Slow:

  • Explosive decompression (ED) is violent, the decompression being too fast for air to safely escape from the lungs.
  • Rapid decompression, while still fast, is slow enough to allow the lungs to vent.
  • Slow or gradual decompression occurs so slowly that it may not be sensed before hypoxia sets in.


The term uncontrolled decompression here refers to the unplanned depressurisation of vessels that are occupied by people; for example, a pressurised aircraft cabin at high altitude, a spacecraft, or a hyperbaric chamber. For the catastrophic failure of other pressure vessels used to contain gas, liquids, or reactants under pressure, the term explosion is more commonly used, or other specialised terms such as BLEVE may apply to particular situations.

Decompression can occur due to structural failure of the pressure vessel, or failure of the compression system itself.[1][2] The speed and violence of the decompression is affected by the size of the pressure vessel, the differential pressure between the inside and outside of the vessel, and the size of the leak hole.

The US Federal Aviation Administration recognizes three distinct types of decompression events in aircraft:[1][2]

  • Explosive decompression
  • Rapid decompression
  • Gradual decompression

Explosive decompression[edit]

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.[1][3] The risk of lung trauma is very high, as is the danger from any unsecured objects that can become projectiles because of the explosive force, which may be likened to a bomb detonation.

After an explosive decompression within an aircraft, a heavy fog may immediately fill the interior as the relative humidity of cabin air rapidly changes as the air cools and condenses. Military pilots with oxygen masks have to pressure-breathe, whereby the lungs fill with air when relaxed, and effort has to be exerted to expel the air again.[4]

Rapid decompression[edit]

Rapid decompression typically takes more than 0.1 to 0.5 seconds, allowing the lungs to decompress more quickly than the cabin.[1][5] The risk of lung damage is still present, but significantly reduced compared with explosive decompression.

Gradual decompression[edit]

Slow, or gradual, decompression occurs slowly enough to go unnoticed and might only be detected by instruments.[1] This type of decompression may also come about from a failure to pressurize as an aircraft climbs to altitude. An example of this is the 2005 Helios Airways Flight 522 crash, in which the pilots failed to check the aircraft was pressurising automatically and then to react to the warnings that the aircraft was depressurising, eventually losing consciousness (along with most of the passengers and crew) from hypoxia.

Pressure vessel seals and testing[edit]

Seals in high-pressure vessels are also susceptible to explosive decompression; the O-rings or rubbergaskets used to seal pressurised pipelines tend to become saturated with high-pressure gases. If the pressure inside the vessel is suddenly released, then the gases within the rubber gasket may expand violently, causing blistering or explosion of the material. For this reason, it is common for military and industrial equipment to be subjected to an explosive decompression test before it is certified as safe for use.


Exposure to a vacuum causes the body to explode[edit]

This persistent myth is based on a failure to distinguish between two types of decompression: the first, from normal atmospheric pressure (one atmosphere) to a vacuum (zero atmospheres); the second, from an exceptionally high pressure (many atmospheres) to normal atmospheric pressure.

The first type, a pressure reduction from normal atmospheric pressure to a vacuum, is the more common. Research and experience in space exploration and high-altitude aviation have shown that while exposure to vacuum causes swelling, human skin is tough enough to withstand the drop of one atmosphere, although the resulting hypoxia will cause unconsciousness after a few seconds.[6][7] At the extreme low pressures encountered at altitudes above about 62,000 feet (19,000 m), only 0.0618 of an atmosphere short of a complete vacuum, the boiling point of water becomes less than normal body temperature; this is known as the Armstrong limit, which is the practical limit to survivable altitude without pressurization.

However, in the case of an explosive or rapid decompression from one atmosphere to zero, pulmonary barotrauma (a rupture of the lung) may occur if the air in the lungs expands faster than the person is able to exhale; if the breath is forcibly held, this can happen even with a gradual decompression.

The second type is rare since it involves a pressure drop over several atmospheres, which would require the person to have been placed in a pressure vessel. The only likely situation in which this might occur is during decompression after deep-sea diving. There is only a single, well-documented occurrence of this: the 1983 Byford Dolphin incident in the North Sea in which a violent, explosive decompression of eight atmospheres, from nine to one atmospheres, caused massive and lethal barotrauma. A similar but fictional death was shown in the James Bond film Licence to Kill, when a character's head explodes after his hyperbaric chamber is rapidly depressurized. Neither of these incidents would have been possible if the pressure drop had been only from normal atmospheric to a vacuum.

Bullets cause explosive decompression[edit]

Aircraft fuselages are designed with ribs to prevent tearing; the size of the hole is one of the factors that determine the speed of decompression, and a bullet hole is too small to cause rapid or explosive decompression.

A small hole will blow people out of a fuselage[edit]

The television program MythBusters examined this belief informally using a pressurised aircraft and several scale tests. The MythBusters approximations suggested that fuselage design does not allow this to happen.

Decompression injuries[edit]

The following physical injuries may be associated with decompression incidents:

Implications for aircraft design[edit]

Modern aircraft are specifically designed with longitudinal and circumferential reinforcing ribs in order to prevent localised damage from tearing the whole fuselage open during a decompression incident.[14] However, decompression events have nevertheless proved fatal for aircraft in other ways. In 1974, explosive decompression onboard Turkish Airlines Flight 981 caused the floor to collapse, severing vital flight control cables in the process. The FAA issued an Airworthiness Directive the following year requiring manufacturers of wide-body aircraft to strengthen floors so that they could withstand the effects of in-flight decompression caused by an opening of up to 20 square feet (1.9 m2) in the lower deck cargo compartment.[15] Manufacturers were able to comply with the Directive either by strengthening the floors and/or installing relief vents called "dado panels" between the passenger cabin and the cargo compartment.[16]

Cabin doors are designed to make it nearly impossible to lose pressurization through opening a cabin door in flight, either accidentally or intentionally. The plug door design ensures that when the pressure inside the cabin exceeds the pressure outside the doors are forced shut and will not open until the pressure is equalised. Cabin doors, including the emergency exits, but not all cargo doors, open inwards, or must first be pulled inwards and then rotated before they can be pushed out through the door frame because at least one dimension of the door is larger than the door frame. Pressurization apparently prevented the doors of Saudia Flight 163 from being opened on the ground after the aircraft made a successful emergency landing, resulting in the deaths of all 287 passengers and 14 crew members from fire and smoke.

Prior to 1996, approximately 6,000 large commercial transport airplanes were type certified to fly up to 45,000 feet (14,000 m), without being required to meet special conditions related to flight at high altitude.[17] In 1996, the FAA adopted Amendment 25-87, which imposed additional high-altitude cabin-pressure specifications, for new designs of aircraft types.[18] For aircraft certified to operate above 25,000 feet (FL 250; 7,600 m), it "must be designed so that occupants will not be exposed to cabin pressure altitudes in excess of 15,000 feet (4,600 m) after any probable failure condition in the pressurization system."[19] In the event of a decompression which results from "any failure condition not shown to be extremely improbable," the aircraft must be designed so that occupants will not be exposed to a cabin altitude exceeding 25,000 feet (7,600 m) for more than 2 minutes, nor exceeding an altitude of 40,000 feet (12,000 m) at any time.[19] In practice, that new FAR amendment imposes an operational ceiling of 40,000 feet on the majority of newly designed commercial aircraft.[20][21][Note 1]

In 2004, Airbus successfully petitioned the FAA to allow cabin pressure of the A380 to reach 43,000 feet (13,000 m) in the event of a decompression incident and to exceed 40,000 feet (12,000 m) for one minute. This special exemption allows the A380 to operate at a higher altitude than other newly designed civilian aircraft, which have not yet been granted a similar exemption.[20]

International standards[edit]

The Depressurization Exposure Integral (DEI) is a quantitativemodel that is used by the FAA to enforce compliance with decompression-related design directives. The model relies on the fact that the pressure that the subject is exposed to and the duration of that exposure are the two most important variables at play in a decompression event.[22]

Other national and international standards for explosive decompression testing include:

Notable decompression accidents and incidents[edit]

Decompression incidents are not uncommon on military and civilian aircraft, with approximately 40–50 rapid decompression events occurring worldwide annually.[23] In the majority of cases the problem is relatively manageable for aircrew.[8] Consequently, where passengers and the aircraft do not suffer any ill effects, the incidents tend not to be considered notable.[8] Injuries resulting from decompression incidents are rare.[8]

Decompression incidents do not occur solely in aircraft—the Byford Dolphin incident is an example of violent explosive decompression on an oil rig. A decompression event is an effect of a failure caused by another problem (such as an explosion or mid-air collision), but the decompression event may worsen the initial issue.

See also[edit]



  1. ^ abcde"AC 61-107A - Operations of aircraft at altitudes above 25,000 feet msl and/or mach numbers (MMO) greater than .75"(PDF). Federal Aviation Administration. 2007-07-15. Retrieved 2008-07-29. 
  2. ^ abDehart, R. L.; J. R. Davis (2002). Fundamentals Of Aerospace Medicine: Translating Research Into Clinical Applications, 3rd Rev Ed. United States: Lippincott Williams And Wilkins. p. 720. ISBN 978-0-7817-2898-0. 
  3. ^Flight Standards Service, United States; Federal Aviation Agency, United States (1980). Flight Training Handbook. U.S. Dept. of Transportation, Federal Aviation Administration, Flight Standards Service. p. 250. Retrieved 2007-07-28. 
  4. ^Robert V. Brulle (2008-09-11). "Engineering the Space Age: A Rocket Scientist Remembers"(PDF). AU Press. Archived from the original(PDF) on 2011-09-28. Retrieved 2010-12-01. 
  5. ^Kenneth Gabriel Williams (1959). The New Frontier: Man's Survival in the Sky. Thomas. Retrieved 2008-07-28. 
  6. ^"Advisory Circular 61-107"(PDF). FAA. pp. table 1.1. 
  7. ^"Flight Surgeon's Guide". United States Air Force. Archived from the original on 2007-03-16. 
  8. ^ abcdefMartin B. Hocking; Diana Hocking (2005). Air Quality in Airplane Cabins and Similar Enclosed Spaces. Springer Science & Business. ISBN 3-540-25019-0. Retrieved 2008-09-01. 
  9. ^ abBason R, Yacavone DW (May 1992). "Loss of cabin pressurization in U.S. Naval aircraft: 1969-90". Aviat Space Environ Med. 63 (5): 341–5. PMID 1599378. 
  10. ^Brooks CJ (March 1987). "Loss of cabin pressure in Canadian Forces transport aircraft, 1963-1984". Aviat Space Environ Med. 58 (3): 268–75. PMID 3579812. 
  11. ^Mark Wolff (2006-01-06). "Cabin Decompression and Hypoxia". Retrieved 2008-09-01. 
  12. ^Robinson, RR; Dervay, JP; Conkin, J. "An Evidenced-Based Approach for Estimating Decompression Sickness Risk in Aircraft Operations"(PDF). NASA STI Report Series. NASA/TM—1999–209374. Archived from the original(PDF) on 2008-10-30. Retrieved 2008-09-01. 
  13. ^Powell, MR (2002). "Decompression limits in commercial aircraft cabins with forced descent". Undersea Hyperb. Med. Supplement (abstract). Retrieved 2008-09-01. 
  14. ^George Bibel (2007). Beyond the Black Box. JHU Press. pp. 141–142. ISBN 0-8018-8631-7. Retrieved 2008-09-01. 
  15. ^"FAA HISTORICAL CHRONOLOGY, 1926-1996"(PDF). Federal Aviation Authority. 2005-02-18. Archived from the original(PDF) on 2008-06-24. Retrieved 2008-09-01. 
  16. ^US 6273365 
  17. ^"Final Policy FAR Part 25 Sec. 25.841 07/05/1996|Attachment 4". 
  18. ^"Section 25.841: Airworthiness Standards: Transport Category Airplanes". Federal Aviation Administration. 1996-05-07. Retrieved 2008-10-02. 
  19. ^ ab"FARs, 14 CFR, Part 25, Section 841". 
  20. ^ ab"Exemption No. 8695". Renton, Washington: Federal Aviation Authority. 2006-03-24. Retrieved 2008-10-02. 
  21. ^Steve Happenny (2006-03-24). "PS-ANM-03-112-16". Federal Aviation Authority. Retrieved 2009-09-23. 
  22. ^"Amendment 25-87". Federal Aviation Authority. Retrieved 2008-09-01. 
  23. ^"Rapid Decompression In Air Transport Aircraft"(PDF). Aviation Medical Society of Australia and New Zealand. 2000-11-13. Archived from the original(PDF) on 2010-05-25. Retrieved 2008-09-01. 
  24. ^Neil Schlager (1994). When technology fails: Significant technological disasters, accidents, and failures of the twentieth century. Gale Research. ISBN 0-8103-8908-8. Retrieved 2008-07-28. 
  25. ^Shayler, David (2000). Disasters and Accidents in Manned Spaceflight. Springer. p. 38. ISBN 1852332255. 
  26. ^"Two MSC Employees Commended For Rescue in Chamber Emergency"(PDF), Space News Roundup, Public Affairs Office of the National Aeronautics and Space AdministrationManned Spacecraft Center, 6 (6), p. 3, January 6, 1967, retrieved July 7, 2012 
  27. ^Ivanovich, Grujica S. (2008). Salyut - The First Space Station: Triumph and Tragedy. Springer. pp. 305–306. ISBN 0387739734. 
  28. ^"Aircraft accident report: American Airlines, Inc. McDonnell Douglas DC-10-10, N103AA. Near Windsor, Ontario, Canada. June 12, 1972"(PDF). National Transportation Safety Board. 1973-02-28. Retrieved 2009-03-22. 
  29. ^"explosive decompression". Retrieved 2017-08-08. 
  30. ^"FAA historical chronology, 1926-1996"(PDF). Federal Aviation Administration. 2005-02-18. Archived from the original(PDF) on 2008-06-24. Retrieved 2008-07-29. 
  31. ^Brnes Warnock McCormick; M. P. Papadakis; Joseph J. Asselta (2003). Aircraft Accident Reconstruction and Litigation. Lawyers & Judges Publishing Company. ISBN 1-930056-61-3. Retrieved 2008-09-05. 
  32. ^Alexander Dallin (1985). Black Box. University of California Press. ISBN 0-520-05515-2. Retrieved 2008-09-06. 
  33. ^United States Court of Appeals for the Second Circuit Nos. 907, 1057 August Term, 1994 (Argued: April 5, 1995 Decided: July 12, 1995, Docket Nos. 94-7208, 94-7218
  34. ^"Aging airplane safety". Federal Aviation Administration. 2002-12-02. Retrieved 2008-07-29. 
  35. ^"Human factors in aircraft maintenance and inspection"(PDF). Civil Aviation Authority. 2005-12-01. Archived from the original(PDF) on 2008-10-30. Retrieved 2008-07-29. 
  36. ^"Fatal Events Since 1970 for Transportes Aéreos Regionais (TAM)". Retrieved 2010-03-05. 
  37. ^"Columbia Crew Survival Investigation Report"(PDF). 2008. pp. 2–90.  
  38. ^"Aircraft Accident Report - Helios Airways Flight HCY522 Boeing 737-31S at Grammatike, Hellas on 14 August 2005"(PDF). Hellenic Republic Ministry Of Transport & Communications: Air Accident Investigation & Aviation Safety Board. Nov 2006. Retrieved 2009-07-14. 
  39. ^
NASA astronaut candidates being monitored for signs of hypoxia during training in an altitude chamber.

VG-BT05 Awakening of Twin Blades

Japanese Name:

Release Date:

January 14th, 2012 (JP)
February 22nd, 2013 (EN)

Awakening of Twin Blades is the 5th Booster Set released in the Japanese/Korean format, and the 7th released in the English format.


  • There are a total of 80 different cards (RRR x8, RR x12, R x20, C x40) + SP cards x12 (Parallel).
  • Includes further support for the Royal Paladin, Shadow Paladin, Kagero, Oracle Think Tank, Nova Grappler, Dimension Police, Dark Irregulars, and Pale Moonclans.
  • Introduces the "Neo Nectar" and "Murakumo" clans.
  • The Japanese version introduces the Cross Ride units.
  • The English version introduces the "Sentinel" keyword.
  • The package illustration features Aichi Sendou, Toshiki Kai and Ren Suzugamori, with Majesty Lord Blaster behind them.
  • The booster's slogan is "Fight and believe in your own strength".


伊藤彰/Azusa/Daisuke Izuka/Eel/funbolt/Hirokorin/koji/Kou Takano/Morechand/NINNIN/Ryo-ta.H/toi8/ToMo/touge666/uni/ZB/安達洋介/雨宮慶太/伊咲ウタ/石田バル/イトウヨウイチ/叶之明/木下勇樹/米谷尚展/茶壱/齋藤タヶオ/齋藤直葵/沙村 広明/山宗/スズキゴロウ/タイキ/高田明美/タカヤマトシアキ/竹浪秀行/田所哲平/たにめそ/千葉サドル/てるみぃ/萩谷薫/パトリシア/前河悠一/前田ヒロユキ/雅/増田幹生/松島一夫/碧風羽/三好載克/村枝賢一/村瀬倫太郎/村山竜大/瞑丸イヌチヨ/山崎太郎/山﨑奈苗/結城遼也/由利真珠郎/余湖裕輝/竜徹/鷲尾直広


カードファイト!! ヴァンガード ブースター第5弾 CM

Japanese Version

뱅가드 쌍검각성0611

Korean version


English version

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Card List

Card No.NameGradeClanTriggerRarity
BT05/001Covert Demonic Dragon, Mandala Lord3MurakumoRRR+SP
BT05/002Majesty Lord Blaster3Royal PaladinRRR+SP
BT05/003Star Call Trumpeter2Royal PaladinRRR+SP
BT05/004Phantom Blaster Overlord3Shadow PaladinRRR+SP
BT05/005Dragonic Overlord the End3KageroRRR+SP
BT05/006Miracle Beauty3Dimension PoliceRRR+SP
BT05/007King of Diptera, Beelzebub3Dark IrregularsRRR+SP
BT05/008Mistress Hurricane3Pale MoonRRR+SP
BT05/009Maiden of Trailing Rose3Neo NectarRR+SP
BT05/010Glass Beads Dragon2Neo NectarRR
BT05/011Maiden of Blossom Rain1Neo NectarRR
BT05/012Stealth Fiend, Midnight Crow2MurakumoRR+SP
BT05/013Stealth Beast, Leaves Mirage1MurakumoRR
BT05/014Knight of Loyalty, Bedivere2Royal PaladinRR
BT05/015Knight of Friendship, Kay1Royal PaladinRR
BT05/016Wingal Brave0Royal PaladinRR+SP
BT05/017Moonlight Witch, Vaha2Shadow PaladinRR
BT05/018Knight of Nullity, Masquerade2Shadow PaladinRR+SP
BT05/019Evil-eye Princess, Euryale3Oracle Think TankRR
BT05/020Street Bouncer2Nova GrapplerRR
BT05/021Frontline Valkyrie, Laurel3Neo NectarR
BT05/022Knight of Harvest, Gene3Neo NectarR
BT05/023Avatar of the Plains, Behemoth3Neo NectarR
BT05/024Iris Knight2Neo NectarR
BT05/025Hey Yo Pineapple2Neo NectarR
BT05/026Shield Seed Squire0Neo NectarR
BT05/027Stealth Fiend, Kurama Lord3MurakumoR
BT05/028Stealth Dragon, Voidgelga3MurakumoR
BT05/029Stealth Beast, Bloody Mist2MurakumoR
BT05/030Caped Stealth Rogue, Shanaou2MurakumoR
BT05/031Stealth Dragon, Cursed Breath2MurakumoR
BT05/032Stealth Dragon, Turbulent Edge1MurakumoR
BT05/033Stealth Beast, Million Rat1MurakumoR
BT05/034Stealth Beast, Evil Ferret0MurakumoR
BT05/035Knight of Purgatory, Skull Face3Shadow Paladin