<http://news.scotsman.com/international.cfm?id=1786222005> http://news.scotsman.com/international.cfm?id=1786222005 Mon 15 Aug 2005 Air crash victims 'frozen solid' say salvage workers BRIAN WILLIAMS AND PHILIP PANGALOS BODIES recovered from a Cypriot airliner which crashed over Greece were found "frozen solid", it emerged today. Rescue workers told of the grim scene as they sifted through the wreckage of the Boeing 737. They have also recovered the plane's two black box flight recorders, including the one that records pilot conversations. It also emerged today that the pilots of the doomed Helios Airways may have become incapacitated "in seconds" following a sudden decompression of the cabin. It is thought all 115 passengers, including 48 children, and six crew were dead before the plane hit the ground. Passengers reportedly sent texts to family and friends shortly before the crash which said the temperature was below freezing and they were short of oxygen. Relatives of some victims were today on their way from Cyprus to the crash site near Athens to start the grim task of trying to identify loved ones. The plane was on a flight from Larnaca in Cyprus to Prague, with a stop in Athens. An airline spokeswoman and Greek authorities ruled out hijacking or terrorism links to the crash. Greek Defence Ministry officials said 90 minutes elapsed between the alert being raised at 10.30 am and the plane crashing at 12.03pm. Greek government spokesman Theodore Roussopoulos said F-16 pilots sent to investigate reported that with the pilots out of action there may have been a last-gasp effort by others on the plane to bring it back under control. "The situation was characterised renegade, meaning the aircraft was not under the control of the pilots," he said. "At a later stage, the F-16s saw two individuals in the cockpit seemingly trying to regain control. "The F-16s also saw oxygen masks down. The aircraft was making right-hand turns to show it had lost radio contact. "A passenger on the doomed plane said in a text to his cousin in Athens: 'The pilot has turned blue. Cousin farewell, we're freezing'." Greece's Defence Ministry said it suspected the plane's oxygen supply or pressurisation system may have malfunctioned, which could have led to death within seconds for all on board. A defence ministry source later said most bodies recovered from the plane were "frozen solid". Loss of cabin pressure was identified as the probable cause of two similar but smaller-scale air crashes in recent years. Golfer Payne Stewart and five others were killed when their Learjet aircraft crashed in the United States in 1999 after flying on autopilot for more than four hours without radio contact. In 2000 a plane crashed in Australia after flying for more than an hour from 25,000 feet up with no sign of life on board. Both the Foreign Office and Helios Airways said they did not believe any Britons had been on the flight. Helios' commercial manager Vicky Xitas, speaking from Larnaca, said: "All our aircraft are checked very, very thoroughly according to international standards. Following the accident, we are doing no more or no less that we normally do in the way of checks and maintenance. "The captain of the plane was German, in his 50s and very experienced. The co-pilot was aged around 45 and also very experienced." Cabin pressurization <http://en.wikipedia.org/wiki/Cabin_pressurization#Pressurized_Flight> http://en.wikipedia.org/wiki/Cabin_pressurization#Pressurized_Flight When a <http://en.wikipedia.org/wiki/Aircraft> aircraft reaches high altitudes, it becomes necessary for the <http://en.wikipedia.org/wiki/Cabin> cabin to be <http://en.wikipedia.org/wiki/Pressure> pressurised. This is because, as the plane gains <http://en.wikipedia.org/wiki/Altitude> altitude, the <http://en.wikipedia.org/wiki/Atmospheric_pressure> atmospheric pressure decreases, and the amount of <http://en.wikipedia.org/wiki/Oxygen> oxygen becomes insufficient for humans to breathe properly. The maximum operational height of a plane includes considerations for cabin pressure. Contents * <http://en.wikipedia.org/wiki/Cabin_pressurization#Unpressurized_Flight> 1 Unpressurized Flight * <http://en.wikipedia.org/wiki/Cabin_pressurization#Pressurized_Flight> 2 Pressurized Flight * <http://en.wikipedia.org/wiki/Cabin_pressurization#Rapid_Loss_of_Pressurizat ion_.28Rapid_Decompression.29> 3 Rapid Loss of Pressurization (Rapid Decompression) * <http://en.wikipedia.org/wiki/Cabin_pressurization#Effects_of_Cabin_Pressuri zation_on_an_Aircraft_Fuselage> 4 Effects of Cabin Pressurization on an Aircraft Fuselage * <http://en.wikipedia.org/wiki/Cabin_pressurization#Effects_of_Cabin_Pressuri zation_on_the_Human_Body> 5 Effects of Cabin Pressurization on the Human Body * <http://en.wikipedia.org/wiki/Cabin_pressurization#Noted_incidents> 6 Noted incidents * <http://en.wikipedia.org/wiki/Cabin_pressurization#See_also> 7 See also * <http://en.wikipedia.org/wiki/Cabin_pressurization#References> 8 References Unpressurized Flight A lack of sufficient oxygen will bring on <http://en.wikipedia.org/wiki/Hypoxia> hypoxia by reducing the <http://en.wikipedia.org/wiki/Alveolar> alveolar oxygen tension. In some individuals, symptoms may begin as low as 1500 <http://en.wikipedia.org/wiki/Metre> metre (5000 <http://en.wikipedia.org/wiki/Feet> feet) above <http://en.wikipedia.org/wiki/Sea_level> MSL, although most passengers can tolerate altitudes of 8,000 feet without ill effect. Passengers may also develop fatigue or <http://en.wikipedia.org/wiki/Headaches> headache as the plane flies higher. As the operational altitude increases, reactions become sluggish and unconsciousness will eventually result. Sustained flight operations above 10,000 feet are generally not possible without pressurisation. Pressurized Flight Aircraft which routinely fly above 10,000 feet are generally pressurized by an <http://en.wikipedia.org/wiki/Environmental_Control_System> Environmental Control System (ECS) using air provided by <http://en.wikipedia.org/wiki/Compressor> compressors or <http://en.wikipedia.org/wiki/Bleed_air> bleed air. These systems maintain air pressure equivalent to 8000 ft or less, even during flight at altitudes above 43,000 ft. As the airplane climbs or descends, some passengers will experience discomfort as trapped gasses within their bodies respond to the changing cabin pressure. The most common problems occur with gas trapped in the <http://en.wikipedia.org/wiki/Gastrointestinal_tract> gastrointestinal tract, the <http://en.wikipedia.org/wiki/Middle_ear> middle ear and the paranasal sinuses. It is always an emergency if a pressurised aircraft suffers a pressurisation failure above 10,000 feet. If this occurs the pilot must immediately place the plane in an <http://en.wikipedia.org/w/index.php?title=Emergency_descent&action=edit> emergency descent and activate emergency <http://en.wikipedia.org/wiki/Oxygen> oxygen for all. Rapid Loss of Pressurization (Rapid Decompression) One consequence of cabin pressurization is that the pressure inside the airplane may be 10 <http://en.wikipedia.org/wiki/Psi> psi, while the pressure outside is barely above 2 psi. A harmless pinhole under these pressure differences will generate a high-pitched squeal as the air leaks out at <http://en.wikipedia.org/wiki/Supersonic> supersonic speeds. A hole only five feet across will depressurize a jetliner in a fraction of a second. Rapid decompression of commercial aircraft is extremely rare, but dangerous. People directly next to a hole may be sucked out or injured by flying debris. Floors and internal panels may deform. Hypoxia will result in loss of conciousness in seconds without emergency oxygen, and the air temperature will plummet due to expansion, potentially resulting in <http://en.wikipedia.org/wiki/Frostbite> frostbite. * Contrary to Hollywood myth, people just a few feet from the hole are more at risk from hypoxia than from being sucked out. * Contrary to Hollywood myth, a bullet hole in a window, or even the loss of an entire passenger window, will not cause rapid decompression. This was demonstrated on <http://en.wikipedia.org/wiki/Mythbusters> Mythbusters. Effects of Cabin Pressurization on an Aircraft Fuselage As the airplane is pressurized and depressurized, the metal skin of the airplane expands and contracts, resulting in <http://en.wikipedia.org/wiki/Metal_fatigue> metal fatigue. Modern aircraft are designed to resist this compression cycle, however some early jetliners (see <http://en.wikipedia.org/wiki/De_Havilland_Comet> De Havilland Comet) had fatal accidents due to underdesign for fatigue. Effects of Cabin Pressurization on the Human Body * <http://en.wikipedia.org/wiki/Ear> Ear and <http://en.wikipedia.org/wiki/Paranasal_sinus> paranasal sinuses - One needs to adjust to the pressurized cabin air from the beginning. 1 in 3 passengers suffer ear discomfort, pain and temporary hearing loss on takeoff or landing, called "aerotitus" by the <http://en.wikipedia.org/w/index.php?title=House_Ear_Institute&action=edit> House Ear Institute in <http://en.wikipedia.org/wiki/Los_Angeles> Los Angeles. Rapid changes in air pressure cause the air pocket inside the ear to expand during takeoff and contract during descent, stretching the <http://en.wikipedia.org/wiki/Eardrum> eardrum. To equalize pressure, air must enter or escape through the <http://en.wikipedia.org/wiki/Eustachian_tube> Eustachian tube. "If a passenger has serious congestion, they risk ear drum damage", says <http://en.wikipedia.org/w/index.php?title=Sigfrid_Soli&action=edit> Sigfrid Soli, <http://en.wikipedia.org/wiki/Ph.D.> Ph.D., head of the HCSD Department at the <http://en.wikipedia.org/wiki/HSI> HSI(?). * <http://en.wikipedia.org/wiki/Tooth> Tooth - Anyone with intestinal gas or gas trapped in an infected tooth may also experience Barodontalgia, a toothache provoked by exposure to changing atmospheric pressure. Noted incidents * Golfer <http://en.wikipedia.org/wiki/Payne_Stewart> Payne Stewart died in an <http://en.wikipedia.org/wiki/Aircraft> aircraft <http://en.wikipedia.org/wiki/Accident> accident as a result of loss of cabin pressure. * A <http://en.wikipedia.org/wiki/Cypriot> Cypriot commercial jet crashed in Greece on <http://en.wikipedia.org/wiki/August_13> August 13, 2005, killing all 121 people on board. It is currently believed that the plane depressurized and the pilots fell unconscious. See also * <http://en.wikipedia.org/wiki/Atmosphere_%28unit%29> Atmosphere (unit) * <http://en.wikipedia.org/wiki/Bleed_air> Bleed air * <http://en.wikipedia.org/wiki/Explosive_decompression> Explosive decompression * <http://en.wikipedia.org/wiki/Gas_compressor> Gas compressor * <http://en.wikipedia.org/wiki/Rarefaction> Rarefaction * <http://en.wikipedia.org/wiki/Spacesuit> Spacesuit References Portions from the <http://www.vnh.org/FSManual/01/07RapidDecompress.html> United States Naval Flight Surgeon's Manual <http://www.cnn.com/2005/WORLD/europe/08/14/greece.crash/index.html> CNN: 121 Dead in Greek Air Crash Environmental Control System The Environmental Control System of an <http://en.wikipedia.org/wiki/Airplane> airplane provides air supply, thermal control and pressurization for the passengers and crew. <http://en.wikipedia.org/wiki/Avionics> Avionics cooling, smoke detection, and <http://en.wikipedia.org/w/index.php?title=Fire_suppression&action=edit> fire suppression are also commonly considered part of the Environmental Control System. Contents * <http://en.wikipedia.org/wiki/Environmental_Control_System#Overview> 1 Overview * <http://en.wikipedia.org/wiki/Environmental_Control_System#Air_supply> 2 Air supply * <http://en.wikipedia.org/wiki/Environmental_Control_System#Air_conditioning_ pack> 3 Air conditioning pack * <http://en.wikipedia.org/wiki/Environmental_Control_System#Ram_Air_System> 4 Ram Air System * <http://en.wikipedia.org/wiki/Environmental_Control_System#Air_Distribution> 5 Air Distribution * <http://en.wikipedia.org/wiki/Environmental_Control_System#Pressurization> 6 Pressurization * <http://en.wikipedia.org/wiki/Environmental_Control_System#Myths> 7 Myths * <http://en.wikipedia.org/wiki/Environmental_Control_System#References> 8 References * <http://en.wikipedia.org/wiki/Environmental_Control_System#External_links> 9 External links Overview The systems described below is specific to current production <http://en.wikipedia.org/wiki/Boeing_Commercial_Airplanes> Boeing <http://en.wikipedia.org/wiki/Airliner> airliners, although the details are essentially identical for passenger jets from <http://en.wikipedia.org/wiki/Airbus> Airbus and other companies. Air supply On most <http://en.wikipedia.org/wiki/Jetliners> jetliners, air is supplied to the ECS by being "bled" off each the <http://en.wikipedia.org/wiki/Compressor> compressor of each <http://en.wikipedia.org/wiki/Jet_engine> jet engine upstream of the <http://en.wikipedia.org/wiki/Combustor> combustor. The <http://en.wikipedia.org/wiki/Temperature> temperature and <http://en.wikipedia.org/wiki/Pressure> pressure of this " <http://en.wikipedia.org/wiki/Bleed_air> bleed air" varies widely depending upon the thrust setting of the engine. A "Pressure Regulating Shutoff Valve" (PRSOV) restricts the flow as necessary to maintain the desired pressure for downstream systems. This flow restriction results in efficiency losses. To reduce the amount of restriction required, and thereby increase efficiency, air is commonly drawn from two bleed ports (3 on the Boeing <http://en.wikipedia.org/wiki/Boeing_777> 777). When the engine is at low thrust, the air is drawn from the "High Pressure Bleed Port." As thrust is increased, the pressure from this port rises until "crossover," where the "High Pressure Shutoff Valve" (HPSOV) closes and air is thereafter drawn from the "Low Pressure Bleed Port." To maintain the desired bleed air temperature, the air is passed through a <http://en.wikipedia.org/wiki/Heat_exchanger> heat exchanger called a "precooler." Air from the <http://en.wikipedia.org/wiki/Jet_engine> jet engine fan is blown across the precooler, which is located in the engine <http://en.wikipedia.org/wiki/Strut> strut. A "Fan Air Modulating Valve" (FAMV) varies the cooling airflow, and thereby controls the final air temperature of the bleed air. On the new Boeing <http://en.wikipedia.org/wiki/Boeing_787> 787, the bleed air will instead be provided by electrically-driven compressors, thereby eliminating the inefficiencies caused by bleed port system. Air conditioning pack The air conditioning package, or "A/C pack" is usually an <http://en.wikipedia.org/wiki/Air_cycle_machine> air cycle machine (ACM) cooling device. Some aircraft, including early <http://en.wikipedia.org/wiki/Boeing_707> 707 <http://en.wikipedia.org/wiki/Jetliners> jetliners, used <http://en.wikipedia.org/w/index.php?title=Vapor_Cycle&action=edit> Vapor Cycle cooling devices like those used in your home <http://en.wikipedia.org/wiki/Air_Conditioner> Air Conditioner. An ACM uses no <http://en.wikipedia.org/wiki/Freon> Freon: the air itself is the <http://en.wikipedia.org/wiki/Refrigerant> refrigerant. The ACM is preferred over vapor cycle devices because of reduced weight and maintenance requirements. On most <http://en.wikipedia.org/wiki/Jetliners> jetliners, the A/C packs are located in the "Wing to Body Fairing" between the two wings beneath the <http://en.wikipedia.org/wiki/Fuselage> fuselage. On most jetliners with tail-mounted engines (Boeing <http://en.wikipedia.org/wiki/Boeing_727> 727, <http://en.wikipedia.org/wiki/Douglas_Aircraft> Douglas Aircraft <http://en.wikipedia.org/wiki/Douglas_DC-9> DC-9, etc) the A/C Packs are located in the tail, although the A/C Packs on the <http://en.wikipedia.org/wiki/McDonnell_Douglas> McDonnell Douglas <http://en.wikipedia.org/wiki/McDonnell_Douglas_DC-10> DC-10 are awkwardly located in the front of the airplane beneath the <http://en.wikipedia.org/wiki/Flight_deck> flight deck. Nearly all jetliners have two packs, except for the Boeing <http://en.wikipedia.org/wiki/Boeing_747> 747, which has three. The quantity of bleed air flowing to the A/C Pack is regulated by the "Flow Control Valve" (FCV). One FCV is installed for each pack. A normally closed "isolation valve" prevents air from the left bleed system from reaching the right pack, although this valve may be opened in the event of loss of one bleed system. Downstream of the FCV, the bleed air enters the primary "Ram Air Heat Exchanger", where it is cooled by ambient air. The cold air then enters the ACM compressor, where it is re-pressurized, which reheats the air. A pass through the secondary "Ram Air Heat Exchanger" cools the air while maintaining the high pressure. When this cool, high-pressure air is expanded through the ACM turbine, the expanding air can be chilled to subfreezing temperatures. The temperature of the Pack Outlet Air is controled by the adjusting flow through the "Ram Air System" (below), and modulating a "Temperature Control Valve" (TCM) which bypasses a portion of the hot bleed air around the ACM and mixes it with the cold air downstream of the ACM turbine. Just like a <http://en.wikipedia.org/wiki/Jet_engine> jet engine, the compressor and turbine are on a single shaft. The energy extracted from the air in the turbine is used to power the compressor - the system has no motor. Ram Air System The "Ram Air Inlet" is a small scoop, generally located on the "Wing to Body Fairing." Nearly all <http://en.wikipedia.org/wiki/Jetliners> jetliners use a modulating door on the ram air inlet to control the amount of cooling airflow through the primary and secondary ram air heat exchangers. To increase ram air recovery, nearly all jetliners use modulating vanes on the ram air exhaust. A "Ram Air Fan" within the ram system provides ram air flow across the heat exchangers when the airplane is on the ground. Nearly all modern airplanes use a fan on a common shaft with the ACM, powered by the ACM turbine. Air Distribution The A/C Pack exhaust air is ducted into the pressurized <http://en.wikipedia.org/wiki/Fuselage> fuselage, where it is mixed with filtered air from the recirculation fans, and fed into the "mix manifold". On nearly all modern <http://en.wikipedia.org/wiki/Jetliners> jetliners, the airflow is approximately 50% "outside air" and 50% "filtered air." Modern jetliners use "High Efficiency Particulate Arresting" <http://en.wikipedia.org/w/index.php?title=HEPA_filters&action=edit> HEPA filters, which trap >99% of all <http://en.wikipedia.org/wiki/Bacteria> bacteria and clustered <http://en.wikipedia.org/wiki/Viruses> viruses. Air from the "mix manifold" is directed to overhead distribution nozzles in the various "zones" of the airplane. Temperature in each zone may be adjusted by adding small amounts of "Trim Air", which is low-pressure, high temperature air tapped off the A/C Pack upstream of the TCV. Pressurization Airflow into the fuselage is approximately constant, and pressure is maintained by varying the opening of the "Out Flow Valve" (OFV). Most modern jetliners have a single OFV located near the bottom aft end of the fuselage, although some larger airplanes like the 747 and 777 have two. In the event the OFV should fail closed, at least two Positive Pressure Relief Valves (PPRV) and at least one Negative Pressure Relief Valve (NPRV) are provided to protect the fuselage from over- and under- pressurization. Airplane cabin pressure is commonly pressurized to a "cabin altitude" of 8000 feet or less. That means that the pressure is 10.9 <http://en.wikipedia.org/wiki/Psia> psia (75 kPa), which is the ambient pressure at 8000 feet (2,400 m). Note that a lower cabin altitude is a higher pressure. The cabin pressure is controlled by a "Cabin Pressure Schedule," which associates each airplane altitude with a cabin altitude. Since jetliners do not always fly at their maximum rated altitude, the cabin altitude is also generally lower than the maximum permitted. For example, domestic flights rarely exceed a 5500 ft cabin altitude. The new Airbus <http://en.wikipedia.org/wiki/Airbus_A380> A380 and <http://en.wikipedia.org/wiki/Boeing_787> 787 jetliners will have lower maximum cabin altitudes. Myths * Do crews turn off one A/C Pack during flight to save fuel? · When one A/C Pack fails or is turned off, the other pack increases flow to ~185% of normal. This is required for safety reasons to maintain cabin pressurization. This may actually increase fuel consumption because the bleed flow is taken asymmetically from the engines. * Is there a switch for the crew to provide less air to the cabin unless the passengers complain? · One of the oldest 747s has a feature to turn off one of the three packs. No recently produced jetliner has this feature. Jetliners are designed to operate with all packs operating at all times. * The bleed air comes from the engines - is there fuel vapor or jet exhaust in the cabin air? · The air is "bled" from the engine upstream of the combustor. Air cannot flow backwards though the engine except during a compressor stall (essentially a jet engine backfire), thus the bleed air should be free of these contaminants from the airplane's own engines. · The bleed air has the same composition as the outside air, thus, when the airplane is on the ground, you are breathing the same air, and the same outdoor contaminants, as the ground crew on the runway. · On rare occasions, jet engine bearing seals can leak grease into the bleed air, but this generally results in a prompt engine maintainance as the failed seal will reduce the engine life. * Is the air in first class better? · Boeing and Airbus jetliners supply constant flow per unit length of the cabin. The seats in first class are spaced farther apart, resulting in more air per seat, but the nozzles provide the same amount of air at all locations. · Since all the air in the main cabin comes from the same manifold, first class receives 50% outside air and 50% filtered recirculated air just like the rest of the cabin. * Is the air in the flight deck better? · Most jetliners supply 100% outside air to the flight deck. This is because the flight deck has the highest concentration of avionics and the most glass per unit volume, making the flight deck very hard to keep cool on hot days. By providing 100% outside air to the flight deck, the air supply temperature can be near freezing if required, much cooler than if the air was mixed with recirculated air. A drawback is that the air in the flight deck is much drier on these airplanes. · Some jetliners provide 50% recirculated air to the flight deck, to increase pilot comfort by raising the humidity. * Are the cargo compartments pressurized? · The cargo compartment is pressurized to the same level as the cabin, although the temperature is generally colder. References American Society of Heating, Ventilation, and Air conditioning Engineers, ASHRAE Handbook - Applications(1999) <http://en.wikipedia.org/w/index.php?title=Special:Booksources&isbn=18834137 10> ISBN 1883413710 External links * <http://www.airbus.com/media/healthy_cabin.asp> Airbus ECS link * <http://www.boeing.com/commercial/cabinair/> Boeing ECS link * <http://www.hamiltonsundstrand.com/hsc/details/0,,CLI1_DIV22_ETI3026,00.html > Hamilton-Sundstrand ECS link * <http://www.honeywellaerospace.com/prod_byfamily_ess_iecs.htm> Honeywell (formerly Allied-Signal) ECS link Loss of <http://en.wikipedia.org/wiki/United_Airlines_Flight_232> United Airlines Flight 232, <http://en.wikipedia.org/wiki/Japan_Airlines_Flight_123> Japan Airlines Flight 123, and <http://en.wikipedia.org/wiki/China_Airlines_Flight_611> China Airlines Flight 611 Air safety >From Wikipedia, the free encyclopedia. Contents * <http://en.wikipedia.org/wiki/Air_safety#Navigation_aids> 1 Navigation aids * <http://en.wikipedia.org/wiki/Air_safety#Air_safety_topics> 2 Air safety topics * <http://en.wikipedia.org/wiki/Air_safety#Dangers> 2.1 Dangers * <http://en.wikipedia.org/wiki/Air_safety#Lightning> 2.1.1 Lightning * <http://en.wikipedia.org/wiki/Air_safety#Engine_failure> 2.1.2 Engine failure * <http://en.wikipedia.org/wiki/Air_safety#Metal_fatigue> 2.1.3 Metal fatigue * <http://en.wikipedia.org/wiki/Air_safety#Delamination> 2.1.4 Delamination * <http://en.wikipedia.org/wiki/Air_safety#Stalling> 2.1.5 Stalling * <http://en.wikipedia.org/wiki/Air_safety#Fire> 2.1.6 Fire * <http://en.wikipedia.org/wiki/Air_safety#Bird_Strike> 2.1.7 Bird Strike * <http://en.wikipedia.org/wiki/Air_safety#Volcanic_ash> 2.1.8 Volcanic ash * <http://en.wikipedia.org/wiki/Air_safety#Human_factors> 2.1.9 Human factors * <http://en.wikipedia.org/wiki/Air_safety#Accidents_and_incidents> 2.2 Accidents and incidents * <http://en.wikipedia.org/wiki/Air_safety#Investigators> 2.3 Investigators * <http://en.wikipedia.org/wiki/Air_safety#Regulation> 2.4 Regulation * <http://en.wikipedia.org/wiki/Air_safety#See_also> 3 See also * <http://en.wikipedia.org/wiki/Air_safety#External_links> 4 External links ] Navigation aids One of the first <http://en.wikipedia.org/wiki/Air_navigation#Navigation_Aids> navigation aids to be introduced was the introduction of airfield lighting to assist pilots to make landings in poor weather or after dark, introduced in the USA in the late 1920s. The concept of approach lightning was developed from this in the <http://en.wikipedia.org/wiki/1930s> 1930s, indicating to the pilot the angle of descent to the airfield, which later became adopted internationally through the standards of the <http://en.wikipedia.org/wiki/International_Civil_Aviation_Organization> International Civil Aviation Organization (ICAO). With the spread of <http://en.wikipedia.org/wiki/Radio> radio technology, several experimental radio based navigation aids were developed from the late 20s onwards. These were most successfully used in conjunction with instruments in the cockpit in the form of <http://en.wikipedia.org/wiki/Instrument_Landing_System> Instrument Landing Systems (ILS), first used by a scheduled flight to make a landing in a snowstorm at <http://en.wikipedia.org/wiki/Pittsburgh> Pittsburgh in <http://en.wikipedia.org/wiki/1938> 1938. A form of ILS was adopted by the ICAO for international use in <http://en.wikipedia.org/wiki/1949> 1949. Following the development of <http://en.wikipedia.org/wiki/Radar> radar in <http://en.wikipedia.org/wiki/World_War_II> World War II, it was deployed as a landing aid for civil aviation in the form of <http://en.wikipedia.org/w/index.php?title=Ground_Control_Approach&action=ed it> Ground Control Approach (GCA) systems, joined in <http://en.wikipedia.org/wiki/1948> 1948 by <http://en.wikipedia.org/wiki/Distance_Measuring_Equipment> Distance Measuring Equipment (DME), and in the <http://en.wikipedia.org/wiki/1950s> 1950s by airport surveillance radar as an aid to <http://en.wikipedia.org/wiki/Air_traffic_control> air traffic control. All of the ground-based navigation aids are rapidly being displaced by satellite-based aids like <http://en.wikipedia.org/wiki/Global_Positioning_System> GPS, which make it possible for aircrews to know their position with great precision anywhere in the world. With the arrival of <http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System> Wide Area Augmentation System (WAAS), GPS navigation has become accurate enough for vertical (altitude) as well as horizontal use, and is being used increasingly for instrument approaches as well as en-route navigation. However, since the GPS constellation is a single-point of failure that can be switched off by the U.S. military in time of crisis, ground-based navigation aids are still required for backup. Air safety topics Dangers Lightning While aircraft are able to withstand normal lightning strikes, the dangers of more powerful <http://en.wikipedia.org/wiki/Lightning#Positive_lightning> positive lightning were not understood until the destruction of a glider in <http://en.wikipedia.org/wiki/1999> 1999 <http://www.dft.gov.uk/stellent/groups/dft_avsafety/documents/page/dft_avsaf ety_500699.hcsp> [1]. It has since been suggested that it may have been positive lightning that caused the crash of <http://en.wikipedia.org/wiki/Pan_American_World_Airways> Pan Am <http://en.wikipedia.org/wiki/Pan_Am_Flight_214> Flight 214 in <http://en.wikipedia.org/wiki/1963> 1963. At the present time <http://en.wikipedia.org/wiki/Aircraft> aircraft are not designed to withstand such strikes, since their existence was unknown at the time standards were set. Engine failure Although aircraft are now designed to fly even after the <http://en.wikipedia.org/wiki/Flameout> failure of one or more <http://en.wikipedia.org/wiki/Aircraft_engine> aircraft engines, the failure of the second engine on one side for example is obviously serious or even more when it's all of them, as illustrated by the <http://en.wikipedia.org/wiki/1970> 1970 <http://en.wikipedia.org/wiki/Dominicana_DC-9_air_disaster> Dominicana DC-9 air disaster, when <http://en.wikipedia.org/wiki/Fuel> fuel contamination caused the failure of both engines. To have an emergency <http://en.wikipedia.org/wiki/Landing> landing place is then very important. Metal fatigue can also have similar consequences (see below). A very unusual class of "engine failure" occurred in <http://en.wikipedia.org/wiki/1979> 1979 when a complete engine detached from <http://en.wikipedia.org/wiki/American_Airlines_Flight_191> American Airlines Flight 191, causing damage to the aircraft from which the pilots were unable to recover. Metal fatigue <http://en.wikipedia.org/wiki/Fatigue_%28material%29> Metal fatigue has occasionally caused failure either of the engine (for example in the <http://en.wikipedia.org/wiki/1989> 1989 <http://en.wikipedia.org/wiki/Kegworth_Air_Disaster> Kegworth Air Disaster), or even of the aircraft body, for example of the <http://en.wikipedia.org/wiki/De_Havilland_Comet> De Havilland Comets in <http://en.wikipedia.org/wiki/1953> 1953 and <http://en.wikipedia.org/wiki/1954> 1954. Now that the subject is better understood, rigorous inspection and <http://en.wikipedia.org/wiki/Nondestructive_testing> nondestructive testing procedures are in place to attempt to identify potential problems. Delamination <http://en.wikipedia.org/wiki/Composite_material> Composite materials consist of layers of fibers embedded in a resin matrix. In some cases, especially when subjected to cyclic stress, the fibers may tear off the matrix, the layers of the material then separate from each other - a process called <http://en.wikipedia.org/wiki/Delamination> delamination, and form a <http://en.wikipedia.org/wiki/Mica> mica-like structure which then falls apart. As the failure insidiously develops inside the material, nothing much is shown on the surface; instrument methods (often <http://en.wikipedia.org/wiki/Ultrasound> ultrasound-based) have to be used. On <http://en.wikipedia.org/wiki/November_12> November 12, <http://en.wikipedia.org/wiki/2001> 2001, <http://en.wikipedia.org/wiki/American_Airlines_Flight_587> American Airlines Flight 587 crashed shortly after a takeoff, killing all 260 persons aboard and 5 more on the ground. Both the engines of the <http://en.wikipedia.org/wiki/Airbus_A300-600> Airbus A300-600, the <http://en.wikipedia.org/wiki/Rudder> rudder and the tail fin separated from the plane before impact. Numerous more modern aircrafts developed related problems, but most were discovered before they caused a catastrophic failure. Delamination risk is as old as composite material. Even in <http://en.wikipedia.org/wiki/1940s> 1940s, several <http://en.wikipedia.org/wiki/Yak-9> Yak-9s experienced delamination of <http://en.wikipedia.org/wiki/Plywood> plywood in their construction. Stalling <http://en.wikipedia.org/wiki/Stall> Stalling an aircraft (increasing the angle of attack to a point at which the wings fail to produce enough <http://en.wikipedia.org/wiki/Lift_%28force%29> lift) is a potential danger, but is normally recoverable. Certain devices have been developed to warn the pilot as stall approaches. These include stall warning horns (now standard on virtually all powered aircraft) <http://en.wikipedia.org/wiki/Stick_shaker> stick shakers and voice warnings. The best known stall-related airline accident was the <http://en.wikipedia.org/wiki/Staines_air_disaster> Staines air disaster in <http://en.wikipedia.org/wiki/1972> 1972. Fire Safety regulations control aircraft materials and the requirements for automated fire safety systems. Usually these requirements take the form of required tests. The tests measure flammability and the toxicity of smoke. When the tests fail, they fail on a prototype in an engineering laboratory, rather than in an aircraft. Occasionally these measures have failed. Fire on board the aircraft, especially the toxic <http://en.wikipedia.org/wiki/Smoke> smoke generated, have been the cause of several incidents. An electrical fire on <http://en.wikipedia.org/wiki/Air_Canada_Flight_797> Air Canada Flight 797 in <http://en.wikipedia.org/wiki/1983> 1983 caused the deaths of 23 of the 46 passengers, resulting in the introduction of floor level lighting to assist people to evacuate a smoke filled aircraft. Two years later a fire on the runway caused the loss of 53 lives, 48 from the effects of smoke, in the <http://en.wikipedia.org/wiki/1985> 1985 <http://en.wikipedia.org/wiki/Manchester_air_disaster> Manchester air disaster. This incident raised serious concerns over the standard aircraft emergency evacuation time of ninety seconds, and calls for the introduction of <http://en.wikipedia.org/wiki/Smoke_hood> smoke hoods or <http://en.wikipedia.org/w/index.php?title=Misting_system&action=edit> misting systems although both were rejected. It did result in the introduction of revised overwing emergency exit doors on certain new aircraft, and a small increase in the spacing between seats next to the emergency exit. Bird Strike <http://en.wikipedia.org/wiki/Bird_strike> Bird strike is an aviation term for when there is a collision between a bird and an aircraft. It is a common threat to aircraft safety and has caused a number of fatal accidents. In <http://en.wikipedia.org/wiki/1988> 1988 an <http://en.wikipedia.org/wiki/Ethiopian_Airlines> Ethiopian Airlines <http://en.wikipedia.org/wiki/Boeing_737> Boeing 737 sucked pigeons into both engines during take-off and then crashed in an attempt to return to the <http://en.wikipedia.org/wiki/Bahir_Dar> Bahir Dar airport; of the 104 people aboard, 35 died and 21 were injured. In another incident in <http://en.wikipedia.org/wiki/1995> 1995, a <http://en.wikipedia.org/w/index.php?title=Dassault_Falcon_20&action=edit> Dassault Falcon 20 crashed at a <http://en.wikipedia.org/wiki/Paris> Paris airport during an emergency landing attempt after sucking <http://en.wikipedia.org/wiki/Lapwing> lapwings into its rear engine, which caused an engine failure and a fire in the airplane fuselage; all 10 people on-board were killed. <http://www.icao.int/icao/en/jr/5308_ar1.htm> [2] Modern jet engines have certain limited capability of surviving an ingestion of a bird. Small fast planes, like eg. military jet fighters, are in higher risk than big heavy multi-engine ones. The highest risk of the bird strike is during the takeoff and landing, in low altitudes, which is in the vicinity of the <http://en.wikipedia.org/wiki/Airport> airports. Some airports use active countermeasures, ranging from a man with a shotgun through recorded sounds of predators to employing <http://en.wikipedia.org/wiki/Falconer> falconers. There are also exotic solutions, like eg. planting poisonous grass along the runways that is not palatable to birds, nor to insect that attracts insectivorous birds. Passive countermeasures involve sensible land-use management, avoiding conditions attracting flocks of birds to the area (eg. landfills). Volcanic ash Plumes of <http://en.wikipedia.org/wiki/Volcanic_ash> volcanic ash in the vicinity of active volcanoes present a risk especially for night flights. It is hard and abrasive and can quickly cause significant wear on the propellers and turbocompressor blades, and scratch the cabin windows, impairing visibility. It contaminates fuel and water systems, can jam gears, and can cause a <http://en.wikipedia.org/wiki/Flameout> flameout of the <http://en.wikipedia.org/wiki/Jet_engine> engines. Its particles have low melting point, so they melt in the combustion chamber and the glass mass then sticks on the turbine blades, fuel nozzles, and the combustors, which can lead to a total engine failure. It can get inside the cabin and contaminate everything there, and can damage the airplane electronics. <http://volcanoes.usgs.gov/Hazards/Effects/Ash+Aircraft.html> [3] There are many instances of damage to a jet aircraft in an ash encounter. In one of them in <http://en.wikipedia.org/wiki/1982> 1982, a British Airways <http://en.wikipedia.org/wiki/Boeing_747> Boeing 747 flew through an ash cloud, lost all four engines, and descended from 36,000 feet to only 12,000 feet before the <http://en.wikipedia.org/wiki/Flight_crew> flight crew managed to restart the engines. With the growing density of air traffic, encounters like this are becoming commonplace. In 1991 the aviation industry decided to set up <http://en.wikipedia.org/w/index.php?title=Volcanic_Ash_Advisory_Center&acti on=edit> Volcanic Ash Advisory Centers (VAACs), one for each of 9 regions of the world, acting as liaisons between <http://en.wikipedia.org/wiki/Meteorologist> meteorologists, <http://en.wikipedia.org/wiki/Volcanologist> volcanologists, and the aviation industry. <http://pubs.usgs.gov/fs/fs030-97/> [4] Human factors <http://en.wikipedia.org/wiki/Human_factors> Human factors including pilot <http://en.wikipedia.org/wiki/Error> error are another potential danger, and currently the most common factor of aviation crashes. Much progress in applying human factors to improving aviation safety was made around the time of <http://en.wikipedia.org/wiki/World_War_II> World War II by people such as <http://en.wikipedia.org/wiki/Paul_Fitts> Paul Fitts and <http://en.wikipedia.org/wiki/Alphonse_Chapanis> Alphonse Chapanis. However, there has been progress in safety throughout the history of aviation, such as the development of the pilot's <http://en.wikipedia.org/wiki/Checklist> checklist in <http://en.wikipedia.org/wiki/1937> 1937. <http://www.ama500.jccbi.gov/afss/History/checklst.htm> [5] The ability of the flight crew to continually maintain <http://en.wikipedia.org/wiki/Situation_awareness> situation awareness is a critical human factor in air safety. Failure of the pilots to properly monitor the flight instruments resulted in the crash of <http://en.wikipedia.org/wiki/Eastern_Airlines_Flight_401> Eastern Airlines Flight 401 in <http://en.wikipedia.org/wiki/1972> 1972, and error during take-off and landing can have catastrophic consequences, for example cause the crash of <http://en.wikipedia.org/wiki/Prinair_Flight_191> Prinair Flight 191 on landing (also in 1972), and the <http://en.wikipedia.org/wiki/1958> 1958 <http://en.wikipedia.org/wiki/Munich_air_disaster> Munich air disaster on take-off during a <http://en.wikipedia.org/wiki/Blizzard> blizzard. As in this latter case, other factors such as the <http://en.wikipedia.org/wiki/Weather> weather often contribute to pilot error incidents. The <http://en.wikipedia.org/wiki/Collision> collision of aircraft can take place in the air ( <http://en.wikipedia.org/wiki/1978> 1978 <http://en.wikipedia.org/wiki/PSA_Flight_182> PSA Flight 182) and on the ground ( <http://en.wikipedia.org/wiki/1977> 1977 <http://en.wikipedia.org/wiki/Tenerife_disaster> Tenerife disaster), both of which involved pilot error. Very rarely, flight crew members are arrested or subject to disciplinary action for being intoxicated on the job. In 1990, three <http://en.wikipedia.org/wiki/Northwest_Airlines> Northwest Airlines crew members were sentenced to jail time for flying from <http://en.wikipedia.org/wiki/Fargo%2C_North_Dakota> Fargo, North Dakota to <http://en.wikipedia.org/wiki/Minneapolis-St._Paul_International_Airport> Minneapolis-St. Paul International Airport while drunk. In 2001, Northwest fired a pilot who failed a breathalyzer test after flying from <http://en.wikipedia.org/wiki/San_Antonio%2C_Texas> San Antonio, Texas to Minneapolis-St.Paul. In <http://en.wikipedia.org/wiki/July> July 2002, two America West pilots were arrested just before they were scheduled to fly from <http://en.wikipedia.org/wiki/Miami%2C_Florida> Miami, Florida to <http://en.wikipedia.org/wiki/Phoenix%2C_Arizona> Phoenix, Arizona because they had been drinking alcohol before the flight. The pilots have been fired from America West and the FAA revoked their pilot's licenses. <http://en.wikipedia.org/wiki/As_of_2005> As of 2005 they await trial in a <http://en.wikipedia.org/wiki/Florida> Florida court <http://sptimes.com/2005/02/01/State/Court_blocks_doctors_.shtml> [6]. The incident created a public relations problem and America West has become the object of many jokes about drunk pilots. While these drunk-flying incidents did not result in crashes, they underscore the role that poor human choices can play in air accidents. Human factors incidents are not limited to errors by the pilots. The failure to correctly close a cargo door on <http://en.wikipedia.org/wiki/Turkish_Airlines_Flight_981> Turkish Airlines Flight 981 in <http://en.wikipedia.org/wiki/1974> 1974 resulted in the loss of the aircraft - however the design of the cargo door latch was also a major factor in the incident. Controlled flight into terrain (CFIT) is a class of accident in which a perfectly good aircraft is flown, under control, into terrain. CFIT accidents typically are a result of pilot error or of navigational system error. Some pilots, convinced that advanced electronic navigation systems such as <http://en.wikipedia.org/wiki/GPS> GPS and <http://en.wikipedia.org/wiki/INS> INS coupled with <http://en.wikipedia.org/w/index.php?title=Flight_Management_System&action=e dit> Flight Management System computers are partially responsible for these accidents, have called CFIT accidents "computerized flight into terrain". Failure to protect <http://en.wikipedia.org/wiki/Instrument_Landing_System> Instrument Landing System <http://en.wikipedia.org/wiki/Critical_areas> critical areas can also cause controlled flight into terrain. Crew awareness and monitoring of navigational systems can prevent or eliminate CFIT accidents. <http://en.wikipedia.org/wiki/Crew_resource_management> Crew resource management is a modern method now widely used to improve the human factors of air safety. The <http://en.wikipedia.org/wiki/Aviation_Safety_Reporting_System> Aviation Safety Reporting System, or ASRS is another. <http://en.wikipedia.org/wiki/Terrorism> Terrorism can also be pointed out as a human factor, since some airplanes that have crashed did so after being hijacked, such was the case of the four jet-liners that crashed as part of the <http://en.wikipedia.org/wiki/September_11%2C_2001_attacks> September 11, 2001 attacks. Accidents and incidents * <http://en.wikipedia.org/wiki/Accidents_and_incidents_in_aviation> Accidents and incidents in aviation * <http://en.wikipedia.org/wiki/Flight_data_recorder> Flight data recorder, includes Cockpit voice recorder Investigators * <http://en.wikipedia.org/wiki/Air_Accidents_Investigation_Branch> Air Accidents Investigation Branch (UK) * <http://en.wikipedia.org/wiki/National_Transportation_Safety_Board> National Transportation Safety Board (USA) * <http://en.wikipedia.org/wiki/Transportation_Safety_Board> Transportation Safety Board (Canada) * <http://en.wikipedia.org/wiki/Bundesstelle_f%C3%BCr_Flugunfalluntersuchung> Bundesstelle für Flugunfalluntersuchung (Germany) * <http://en.wikipedia.org/wiki/Bureau_d%27Enqu%C3%AAtes_et_d%27Analyses_pour_ la_s%C3%A9curit%C3%A9_de_l%27Aviation_Civile> Bureau d'Enquêtes et d'Analyses pour la sécurité de l'Aviation Civile (France) * <http://en.wikipedia.org/w/index.php?title=Australian_Transport_Safety_Burea u&action=edit> Australian Transport Safety Bureau (Australia) Regulation * <http://en.wikipedia.org/wiki/Federal_Aviation_Administration> Federal Aviation Administration * <http://en.wikipedia.org/wiki/Federal_Aviation_Regulations> Federal Aviation Regulations * <http://en.wikipedia.org/wiki/United_Kingdom_Civil_Aviation_Authority> United Kingdom Civil Aviation Authority See also * <http://en.wikipedia.org/wiki/Aircraft_hijacking> Aircraft hijacking * <http://en.wikipedia.org/wiki/Airport_security> Airport security * <http://en.wikipedia.org/wiki/Aircraft> Aircraft * <http://en.wikipedia.org/wiki/Aviation> Aviation * <http://en.wikipedia.org/wiki/Aerospace_engineering> Aerospace engineering * <http://en.wikipedia.org/wiki/Flight_data_recorder> Flight data recorder Related topics * <http://en.wikipedia.org/wiki/Road_safety> Road safety External links * <http://aviation-safety.net/> http://aviation-safety.net/ * <http://www.crashdatabase.com/> http://www.crashdatabase.com/ * <http://www.flightsafety.org/> http://www.flightsafety.org/ * <http://www.gao.gov/atext/d0433.txt> Aviation Safety: Advancements Being Pursued to Improve Airliner Cabin Occupant Safety and Health, 2003 * <http://www.thirtythousandfeet.com/regulato.htm> International regulatory & government agencies * <http://airlinesafety.com/> Airline Safety.com * <http://asrs.arc.nasa.gov/report_sets_nf.htm> Aviation Safety Reporting System (ASRS) run by NASA * <http://www.aero.ca/e_adolescence.html> The Adolescence of Aviation Psychology * <http://www.skygod.com/quotes/safety.html> Aviation Safety Quotations Turkish Airlines Flight 981 <http://en.wikipedia.org/wiki/Turkish_Airlines> Turkish Airlines Flight 981 was a flight that flew on a <http://en.wikipedia.org/wiki/Ankara> Ankara- <http://en.wikipedia.org/wiki/Charles_de_Gaulle_International_Airport> Charles de Gaulle International Airport (near <http://en.wikipedia.org/wiki/Paris> Paris) - <http://en.wikipedia.org/wiki/London_Heathrow_Airport> London Heathrow Airport ( <http://en.wikipedia.org/wiki/London> London) route. The aircraft, a <http://en.wikipedia.org/wiki/DC-10> DC-10 was leased from <http://en.wikipedia.org/wiki/American_Airlines> American Airlines in <http://en.wikipedia.org/wiki/1973> 1973. On <http://en.wikipedia.org/wiki/March_3> March 3, <http://en.wikipedia.org/wiki/1974> 1974 the flight (registration number TC-JAV, named "Ankara") was involved in the Ermenonville air disaster a high speed crash into the forest at <http://en.wikipedia.org/wiki/Ermenonville> Ermenonville, <http://en.wikipedia.org/wiki/France> France, only a few minutes after take-off on the Paris-London leg. A defective latch on the cargo door caused it to open in flight, resulting in an <http://en.wikipedia.org/wiki/Explosive_decompression> explosive decompression. The decompression caused the cabin floor near the door to fail, sucking six passengers out of the plane and severing the control cables leading to the tail surfaces. With elevator control lost, the plane lost horizontal stability and dived into the ground at 430 knots. The plane left a trail over a kilometer long through the forest, and few pieces larger than a meter were left. All 346 people aboard were killed in the accident. A large number of these were English rugby fans who had transferred to the plane after their own flight had been canceled due to a <http://en.wikipedia.org/wiki/Strike_action> strike in London. It was the worst air <http://en.wikipedia.org/wiki/Disaster> disaster of all time until the <http://en.wikipedia.org/wiki/Tenerife_disaster> Tenerife Disaster of 1977, and the worst single-airplane disaster before the crash of the <http://en.wikipedia.org/wiki/Japan_Airlines_Flight_123> Japan Airlines Flight 123 of <http://en.wikipedia.org/wiki/1985> 1985. The hatch of the DC-10 is an interesting study in <http://en.wikipedia.org/wiki/Human_factors> human factors, <http://en.wikipedia.org/wiki/Interface_design> interface design and <http://en.wikipedia.org/w/index.php?title=Engineering_responsibility&action =edit> engineering responsibility. The control cables for the rear control surfaces of the DC-10 are routed around the hatch, so a failure of the hatch could lead to the disruption of the controls. To make matters worse, Douglas chose a new latch design to close it. If the hatch were to fail for any reason, there was a very high probability the plane would be lost. This possibility was first discovered in 1969, and actually occurred in 1970 in a ground test. Nevertheless nothing was done to change the design, as any such changes would be made out-of-pocket by the fuselage main-contractor, <http://en.wikipedia.org/wiki/Convair> Convair. The first hatch related accident ( <http://en.wikipedia.org/wiki/American_Airlines_Flight_96> American Airlines Flight 96) occurred in June 1972 on a flight from <http://en.wikipedia.org/wiki/Detroit> Detroit to <http://en.wikipedia.org/wiki/Toronto> Toronto, when the hatch was closed improperly by ground crew unfamiliar with the new latch design. The hatch blew off at 12,000ft, destroying the rudder control completely and damaging the elevator controls, but quick thinking on the part of the pilot and the help of a general aviation pilot in the cabin allowed the plane to land with no injuries. The <http://en.wikipedia.org/wiki/NTSB> NTSB made several recommendations in the wake of this first accident, but the <http://en.wikipedia.org/wiki/Federal_Aviation_Administration> FAA didn't order any of them made, instead Convair agreed to carry them out voluntarily. However, these modifications were never actually carried out. Ship 29, the one that crashed at Ermenonville, had been certified by three inspectors at Convair's <http://en.wikipedia.org/wiki/Long_Beach> Long Beach plant as having been modified, but nothing had actually been done (Indeed, a manufacturing error meant that the door latch on Ship 29 was even flimsier than on other unmodified DC-10s). All of this came out in the post-crash investigation, leading to a number of changes in the FAA's reporting chain. Similar accidents Outward opening cargo doors are inherently non-fail safe. While an inward opening door (a <http://en.wikipedia.org/w/index.php?title=Plug_door&action=edit> plug door) which is unlatched will not open due to the pressure differential, an outward opening, non-plug type door needs to be locked shut to prevent unwanted opening. This makes it particularly important that the locking mechanisms be secured. Other aircraft types than the DC-10 have experienced catastrophic failures of a door: The <http://en.wikipedia.org/wiki/Boeing_747> Boeing 747 has experienced a number of such incidents - the most noteworthy of which occurred aboard <http://en.wikipedia.org/wiki/United_Airlines> United Airlines flight 811 on 24th <http://en.wikipedia.org/wiki/February> February, <http://en.wikipedia.org/wiki/1989> 1989, when the cargo door failed, and caused a section of the fuselage to fail, resulting in the deaths of 9 passengers who were expelled from the aircraft. See also * <http://en.wikipedia.org/wiki/Lists_of_accidents_and_incidents_on_commercial _airliners> Lists of accidents and incidents on commercial airliners Articles in category "In-flight airliner structural failures" There are 9 articles in this category. A * <http://en.wikipedia.org/wiki/Aloha_Flight_243> Aloha Flight 243 * <http://en.wikipedia.org/wiki/American_Airlines_Flight_191> American Airlines Flight 191 * <http://en.wikipedia.org/wiki/American_Airlines_Flight_587> American Airlines Flight 587 C * <http://en.wikipedia.org/wiki/China_Airlines_Flight_358> China Airlines Flight 358 * <http://en.wikipedia.org/wiki/China_Airlines_Flight_611> China Airlines Flight 611 D * <http://en.wikipedia.org/wiki/De_Havilland_Comet> De Havilland Comet J * <http://en.wikipedia.org/wiki/Japan_Airlines_Flight_123> Japan Airlines Flight 123 T * <http://en.wikipedia.org/wiki/Turkish_Airlines_Flight_981> Turkish Airlines Flight 981 U * <http://en.wikipedia.org/wiki/United_Airlines_Flight_811> United Airlines Flight 811 Bruce Tefft <[EMAIL PROTECTED]> wrote: -----Original Message----- From: Sent: Monday, August 15, 2005 2:29 PM To: [EMAIL PROTECTED] Subject: More questions that need to be answered. So - OK which is it? "BODIES recovered from a Cypriot airliner which crashed over Greece were found "frozen solid", it emerged today. " OK It also emerged today that the pilots of the doomed Helios Airways may have become incapacitated "in seconds" following a sudden decompression of the cabin. OK It is thought all 115 passengers, including 48 children, and six crew were dead before the plane hit the ground. OK Passengers reportedly sent texts to family and friends shortly before the crash which said the temperature was below freezing and they were short of oxygen. NOT OK - I thought they were dead within seconds. It takes longer than seconds to send a text message. Greek government spokesman Theodore Roussopoulos said F-16 pilots sent to investigate reported that with the pilots out of action there may have been a last-gasp effort by others on the plane to bring it back under control. "The situation was characterised renegade, meaning the aircraft was not under the control of the pilots," he said. "At a later stage, the F-16s saw two individuals in the cockpit seemingly trying to regain control. NOT OK - I thought they were dead within seconds. I thought everyone was dead beore the plane hit the group. Who was trying to regain control? Why weren't they frozen? Why weren't they dead. The plane had been flying as renegade for quite some time. "The F-16s also saw oxygen masks down. The aircraft was making right-hand turns to show it had lost radio contact. NOT OK - I thought they were dead within seconds. Who is making the right hand turns? "A passenger on the doomed plane said in a text to his cousin in Athens: 'The pilot has turned blue. Cousin farewell, we're freezing'." NOT OK - I thought they were dead within seconds. It takes longer than seconds to send a text message. Greece's Defence Ministry said it suspected the plane's oxygen supply or pressurisation system may have malfunctioned, which could have led to death within seconds for all on board. A defence ministry source later said most bodies recovered from the plane were "frozen solid". NOT OK - who was trying to fly the plane. [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> <font face=arial size=-1><a href="http://us.ard.yahoo.com/SIG=12h24tmms/M=362329.6886306.7839369.3040540/D=groups/S=1705323667:TM/Y=YAHOO/EXP=1124152879/A=2894321/R=0/SIG=11dvsfulr/*http://youthnoise.com/page.php?page_id=1992 ">Fair play? Video games influencing politics. Click and talk back!</a>.</font> --------------------------------------------------------------------~-> -------------------------- Want to discuss this topic? Head on over to our discussion list, [EMAIL PROTECTED] -------------------------- Brooks Isoldi, editor [EMAIL PROTECTED] http://www.intellnet.org Post message: [email protected] Subscribe: [EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] *** FAIR USE NOTICE. 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