Trans World Airlines Flight 800 ( TWA 800 ) is a Boeing 747-100 that exploded and crashed into the Atlantic Ocean near East Moriches, New York, on July 17, 1996, at about 8: 31 pm EDT, 12 minutes after takeoff from John F. Kennedy International Airport on an international scheduled flight passenger to Rome, with a stopover in Paris. All 230 people in it were killed in the third deadliest aviation accident in US history. Accident investigators from the National Transportation Safety Agency (NTSB) traveled to the scene, arriving the next day amid speculation that a terrorist attack was the cause of the crash. As a result, the Federal Bureau of Investigation (FBI) initiated a parallel criminal investigation. Sixteen months later, the FBI announced that there was no evidence of criminal activity and closing its active inquiry.
The four-year NTSB investigation concludes with the approval of the Aircraft Accident Report on August 23, 2000, ending the most extensive, complex and expensive air disaster investigation in US history. The report's conclusion is that the probable cause of the accident is the explosion of combustible steam fuel in the central fuel tank. Although it can not be determined with certainty, the ignition source may be shorted. Problems with aircraft cables are found, including evidence of curvature on the Fuel Quantity Indication (FQIS) system that enters the tank. FQIS on Flight 800 is known to have been damaged; The captain commented on what he called "insane" readings of the system about two minutes and thirty seconds before the plane exploded. As a result of the investigation, new requirements are developed for aircraft to prevent future fuel tank explosions.
TWA Flight 800 conspiracy theories exist, the most common being that missile strikes from terrorists or the unintentional launch of US Navy ships cause accidents and are the subject of government closure.
Video TWA Flight 800
Flight accidents
The crash aircraft, registration N93119, (Boeing 747-131) manufactured by Boeing in July 1971; had been ordered by Eastern Air Lines, but after Eastern canceled the order 747, the plane was purchased new by TWA. The aircraft has completed 16,869 flights with 93,303 hours of operation. On the day of the crash, the plane departed from Ellinikon International Airport in Athens, Greece as TWA Flight 881 and arrived at John F. Kennedy International Airport (JFK) at around 16:38. The aircraft was refueling, and there was a change of crew; The new crew consists of Captain Ralph G. Kevorkian, 57-year-old Airman Captain/Airman, Steven E. Snyder, and Flight Engineer/Airman 63 year old Richard G. Campbell (all of whom are highly experienced veterans flying with TWA), as well as engineer trainers 25-year-old flight Oliver Krick, who started the sixth leg of his initial operating experience training.
The ground maintenance crew locked a reversal of thrust power for engine # 3 (treated as a minimum equipment list item) due to technical problems with the thrust reverser sensor during the TWA 881 landing on JFK, prior to Flight 800 departure. In addition, the disconnected cable for the thrust reversing machine # 3 replaced. During aircraft refueling, the volumetric shutoff control (VSO) is believed to have been triggered before the tank is full. To continue the fuel pressure, mechanical TWA VSO overrode automatically by pulling volumetric fuses and overflow circuit breakers. The maintenance records indicate that the aircraft had a lot of maintenance maintenance associated with VSO in the weeks before the accident.
TWA 800 is scheduled to depart from JFK to Paris around 7:00 pm, but the flight is delayed until 8:02 pm. by defective ground equipment and passenger/luggage misfit. Once the owner of the checked luggage is confirmed on board, the crew is preparing for departure and the plane is pushed back from Gate 27 at TWA Flight Center. Taxis and takeoff run smoothly.
TWA 800 then receives a series of title changes and generally improves altitude tasks as it rises to its intended cruising altitude. The weather in the area was a gentle breeze with scattered clouds, and there was an evening light. The last radio transmission from an airplane occurred at 8:30 pm. when the crew received and then admitted the instructions from the Boston Center to climb up to 15,000 feet (4,600m). The last radar transponder recovered from the aircraft was recorded by the Federal Aviation Administration (FAA) radar site in Trevose, Pennsylvania at 8:31:12 pm.
Thirty-eight seconds later, the captain of the Eastwind Airlines Boeing 737 reported to the Boston ARTCC that he "had just seen an explosion out here", adding, "we just saw an explosion in front of us here... about 16,000 feet (4,900 ×, m) or something like that, it just goes down to the water. "Furthermore, many air traffic control facilities in the New York/Long Island region receive explosive reports from other pilots operating in the area. Many witnesses around the crash claimed that they saw or heard the explosion, accompanied by a large fireball or fireball over the ocean, and observed the debris, some of it burning when it fell into the water.
Various civilian, military, and police vessels reached the crash site and searched for survivors within minutes of the initial water impact, but did not find it, making TWA the 800 second deadliest plane crash in US history at the time.
Maps TWA Flight 800
Initial investigation
NTSB was notified about 8:50 pm on the day of the accident; full team go gathered in Washington, D.C. and arrived at the scene the following morning. Meanwhile, the initial witness testimony led many to believe that the cause of the accident was a bomb or a surface-to-air missile attack. NTSB does not investigate criminal activity. The Attorney General is empowered to declare an investigation to be linked to a criminal offense, and requires the NTSB to relinquish control of the investigation to the FBI. In the case of TWA 800, the FBI started a parallel criminal investigation along with the NTSB crash investigation.
Search and recovery operations
Search and recovery operations are carried out by federal, state, and local agencies, as well as government contractors. The HH-60 helicopter from New York Air National Guard saw an explosion of about eight miles away, and arrived so quickly that the debris was still raining, and the plane had to pull away. They reported their sightings to the tower at Suffolk County Airport (now Gabreski ANG Base). Remotely operated vehicles (ROVs), side-scan sonar, and laser lineage scanners are used to search and investigate areas of underwater debris. Victims and wrecks discovered by scuba divers and ROVs; then shellfish trawlers are used to restore the wreckage that is embedded in the bottom of the ocean. In one of the largest rescue operations ever undertaken, often working in extremely difficult and dangerous conditions, over 95% of the aircraft's wreckage is recovering. The search and recovery effort identified three major areas of underwater debris. The yellow zones, red zones, and green zones contain debris from the front, center, and rear of the plane, respectively. The green zone with the rear of the plane lies farthest along the flight path.
- Debris recovery and field debris
Pieces of debris were transported by boat to shore and then by truck to rent hangar space at Grumman Aircraft's former facility in Calverton, New York, for storage, inspection and reconstruction. This facility became the command center and headquarters for investigation. NTSB and FBI personnel were present to observe all transfers to maintain the evidentiary value of the plane debris. Cockpit voice recorder and flight data recorder discovered by US Navy divers 1 week after accident; they were immediately sent to the NTSB lab in Washington, D.C., to read. The remains of the victims were transported to the Suffolk County Medical Examination Office in Hauppauge, New York.
Tension in investigation
Relatives of passengers and crew of TWA 800, as well as media, gathered at Ramada Plaza JFK Hotel. Many are waiting until the remains of their family members have been found, identified, and released. The hotel is known as the "Heartbreak Hotel" because of its role in handling the families of victims of multiple plane crashes. The New York Daily News writes that for family hotels it is "an emergency sadness counseling center".
Sadness turns to anger over TWA delays in confirming passenger lists, conflicting information from agencies and officials, and distrust of priority recovery operations. Although NTSB's deputy chairman Robert Francis stated that all bodies were taken as soon as they were seen, and the debris was being restored only if the diver believes that the victim is hidden beneath it, many families suspect that the investigator is dishonest, or withhold information.
Much anger and political pressure were also directed at the Suffolk County Medical Examiner. Charles V. Wetli when the corpses were rescued back into the mortuary. Under constant pressure and large enough to identify the victim with minimal delay, the pathologist works non-stop. Since the main purpose is to identify all residuals rather than perform detailed forensic autopsies, the accuracy of the examinations varies greatly. In the end, the remaining 230 victims were found and identified, the last more than 10 months after the accident.
With unclear lines of authority, the differences in agenda and culture between the FBI and NTSB result in disputes. The FBI, from the outset assumed that criminal action had taken place, saw the NTSB as hesitant. Expressing the frustration over NTSB's reluctance to speculate about a cause, an FBI agent described the NTSB as "No opinion, nothing." Meanwhile, NTSB was asked to reject or downplay speculation about conclusions and evidence, often supplied to journalists by law enforcement officers and politicians. The International Association of Machinists and Aerospace Workers (IAMAW), a party invited to the NTSB investigation, criticized the unlawful removal by FBI agents from wrecks from the hangars in which it was stored.
Witness Interview
Despite the considerable differences between different accounts, most of the accident witnesses had seen "a beam of light" that was unanimously described as ascending, moving to the point where a large fireball appeared, with several witnesses reporting that the fireball was split in two as it down toward the water. There is a strong public interest in witness accounts and much speculation that the reported light circuit is a missile struck TWA 800, causing the plane to explode. This witness account is the main reason for the initiation and length of the FBI criminal investigation.
About 80 FBI agents conduct interviews with prospective witnesses daily. No word-to-word notes from the resulting witness interviews; On the contrary, the interviewing agents write a summary that they then propose. Witnesses are not required to review or correct the summary. Included in some witness summaries are the pictures or diagrams of what witnesses observe. Witnesses are not allowed to testify in court.
Within days of the collision, NTSB announced its intention to form its own witness group and interview witnesses about the accident. After the FBI raised concerns about non-governmental parties in the NTSB investigation that had access to this information and the possibility of prosecution as a result of several interviews from the same witness, the NTSB delayed and did not interview the witnesses of the accident. A Security Agency investigator then reviewed the FBI interview record and briefed the other Supervisory Board about its contents. In November 1996, the FBI agreed to allow NTSB access to a summary of witness statements in which personally identifiable information has been edited and to conduct limited number of witness interviews. In April 1998, the FBI provided the NTSB with the identity of witnesses but due to the elapsed time, the decision was made to rely on the original FBI documents and not from re-interviews.
Investigation and further analysis
The cockpit voice recorder (CVR) and flight recorder data record shows normal takeoff and climbing, with the plane in normal flight before abruptly stops at 8:31:12 pm. At 8: 29: 15 pm the captain was heard saying, "Look at the crazed fuel flow indicator there at number four... look at that?" A voice recorded on some of the last tenths of the CVR is similar to the last recorded sound from another aircraft experiencing a flight break. This, along with the sharing of junk reports and witnesses, all show the destruction of the sudden flight of TWA 800.
Possible cause of separation in plane
The researchers considered several possible causes of structural breakage: structural failure and decompression, high explosive explosive devices, such as a missile warhead that exploded well when hit by a plane, or just before a collision, a bomb exploded inside a plane, or an explosion of air fuel at center wing fuel tank.
Structural and Decompression Failures
A close examination of the wreck does not show evidence of structural errors such as fatigue, corrosion or mechanical damage that can lead to flight breaks. It is also suggested that the breakup may have been initiated by the separation of the flight at the front cargo gate like a disaster on board the Turkish Airlines Flight 981 or United Airlines Flight 811, but all the evidence indicates that the door is closed and locked in impact.. NTSB concludes that "the flight termination of the flight TWA 800 was not initiated by a pre-existing condition that resulted in structural failure and decompression."
Launch of a missile or live bomb
A review of data recorded from long-range radar radars and airport supervisory radar revealed some contacts of aircraft or objects around TWA 800 at the time of the accident. None of these contacts cut the TWA 800 position at any time. Attention is drawn to data from Islip, New York, the ARTCC facility that shows three tracks around TWA 800 that do not appear in any of the other radar data. None of these sequences cut the TWA 800 position at any time. All the radar data reviewed showed no radar consistent with missiles or other projectiles moving toward TWA 800.
The NTSB responded to allegations that the Islip radar data showed military surface target groups gathering in suspicious ways in the area around the crash, and that the 30-node radar, never identified and 3 nautical miles (5.6 km, 3.5 mi) accidents, engage in fraud, as evidenced by his failure to divert from his track and assist with search and rescue operations. The military records examined by the NTSB show no surface military ship within 15 nautical miles (28 km/17 miles) of the TWA 800 at the time of the crash. In addition, the records show that the closest area scheduled for military use, warning area W-387A/B, is 160 nautical miles (296 km; 184Ã, mi) south.
NTSB reviewed the 30-node target path to try to determine why it did not divert from its track and continue to the area where the TWAÃ,800 ruins had fallen. TWA 800 is behind the target, and with the possibility of a forward-looking perspective of the target occupants, the occupants will not be in a position to observe the outbreak of the plane or the next blast or fireball (s). In addition, it is unlikely that the occupants of the target track will be able to hear the explosion above the sound of the engine and the sound of the stomach passing through the water, even more so if the occupants are on a bridge or enclosed cabin. Further, a review of the Islip radar data for other similar summer days in 1999 showed that 30-knot trajectories consistent with normal commercial fishing, recreation, and cargo ship traffic.
- Radar data recordings
The number of explosive residual traces detected on three material samples from three separate locations from the wreckage of the discovered plane (described by the FBI as part of a material such as a canvas and two floor panes). These samples were sent to the FBI laboratory in Washington, D.C., which determined that one sample contained traces of cyclotrimethylenetrinitramine (RDX), other nitroglycerin, and the three combinations of RDX and pentaerythritol tetranitrate (PETN); These findings got a lot of media attention at the time. In addition, the backs of several broken passenger seats were observed to have unknown red/brown-shaded substances in them. According to the seat manufacturer, the location and appearance of these substances is consistent with the adhesives used in chair construction, and additional laboratory testing by NASA identifies the substance as consistent with the adhesive.
Further examination of the structure of aircraft, seats, and other interior components did not find the damage normally associated with high-energy explosions from bombs or warhead missiles ("severe pitting, crater, petalling, or hot gas washing"). These include pieces that track the number of explosives found. Of the 5 percent of the airframe that has not recovered, there is not a large lost area large enough to cover any damage that may be caused by a bomb or missile explosion. None of the remains of the victim showed evidence of injuries that might be caused by high-energy explosives.
The NTSB considers the possibility that the explosive residue is due to contamination of the use of aircraft in 1991 transporting troops during the Gulf War or its use in explosive detection training of dog training about a month before the accident. Tests conducted by the FAA Technical Center show that residues of the type of explosives found in the debris will disappear completely after two days of submersion in seawater (most of the restored ruins are soaked longer than two days). The NTSB concluded that it was "very likely" that explosive residues were detected transferred from military vessels or land vehicles, or clothing and boots from military personnel, to debris during or after recovery operations and none when the aircraft crashed into the water.
Although unable to determine the exact source of trace amounts of explosive residue found in the ruins, the lack of other corroborative evidence associated with high-energy explosions led NTSB to conclude that "the termination of a TWA flight in an 800 flight was not initiated by a bomb or missile attack."
The fuel explosion in the center wing fuel tank
To evaluate the structural disconnection order of the aircraft, NTSB formed the Sequencing Group, which examined individual pieces of recoverable structures, two-dimensional reconstructions or plane layout sections, and various three-dimensional reconstructions of parts of the aircraft. In addition, the locations of scrap pieces during recovery and differences in fire effects on pieces that are normally adjacent to each other are evaluated. The Sequencing Group concluded that the first event in the break order was a fracture in the center of the aircraft wing, caused by an "overpressure event" in the central wing fuel tank (CWT). The overpressure event is defined as a rapid increase in pressure resulting in failure of the CWT structure.
Since there is no evidence that an explosive device is detonated in this (or other) area of ​​an aircraft, this overpressure event can only be caused by a fuel/air explosion in the CWT. There are 50 US gallons (190 Â ° L) of fuel in the CWT TWA 800; the test creates a flight condition indicating a combination of liquid fuel and fuel/air vapor being flammable. The main reason for the combustible fuel/air vapor in the CWT of 747 is the large amount of heat generated and transferred to the CWT by an AC packet located just below the tank; with the CWT temperature elevated to a sufficient level, a single ignition source can cause an explosion.
Computer modeling and scale modeling tests are used to predict and show how explosions will develop in 747 CWT. During this time, quenching is identified as a problem, where the explosion will extinguish itself as it passes through the complex structure of the CWT. Because research data on quenching is limited, a complete understanding of quenching behavior is not possible, and quenching problems remain unsolved.
To better determine whether the fuel/air vapor explosion at CWT would produce sufficient pressure to break the fuel tank and lead to the destruction of the aircraft, the tests were conducted in July and August 1997, using a retired Air France 747 at Bruntingthorpe Airfield, England. These tests simulate a fuel/air blast at the CWT by lighting a propane/air mixture; this resulted in the failure of the tank structure due to overpressure. While the NTSB acknowledged that the test conditions at Bruntingthorpe were not entirely comparable to the existing conditions at TWA 800 at the time of the crash, previous fuel explosions at CWT from commercial aircraft such as Avianca Flight 203 and Philippine Airlines Flight 143 confirmed that the CWT explosion could break up fuel tanks and causing the destruction of aircraft.
In the end, based on "the series of plane crash accidents, the characteristics of the damage to the wreck, scientific tests and research on fuel, fuel tank explosions, and conditions in CWT at the time of the accident and witness information analysis," NTSB concluded that "Termination of TWA 800 flight within the flight was initiated by a fuel/air blast at CWT. "
In-flight breakup sequence and unbalanced flight
Recovery sites from debris from the sea (red, yellow, and green zones) clearly show that: (1) the red area pieces (from the front of the center of the wing and the body ring directly ahead) are the earliest pieces to separate from airplane; (2) the front fuselage departs simultaneously with or immediately after pieces of the red area, landing relatively intact in the yellow zone; (3) pieces of green area (wings and the back of the fuselage) remain intact for the period after the separation of the front fuselage, and affect the water in the green zone.
Damage caused by fires and sediment of soot in the wreckage was found indicating that several areas of fire were on the plane as the plane continued to fly on a paralyzed flight after the missing plane was lost. After about 34 seconds (based on information from witness documents), the outside of the right and left wing fails. Shortly thereafter, the left wing was separated from what was left of the main fuselage, which resulted in the further development of balls fed with fuel as scraps of junk fell into the ocean.
Only the FAA radar facility in North Truro, Massachusetts, uses special processing software from the 84th Air Force Radar Air Squadron of the United States Air Force, capable of estimating TWA 800 altitude after power loss due to CWT explosion. Because of the limitations of accuracy, this radar data can not be used to determine whether the plane rises after the nose is separated. Instead, the NTSB conducted a series of computer simulations to examine the flight path from the main body of the fuselage. Hundreds of simulations were run using a variety of time combinations that allowed a separate TWA 800 nose (exact time unknown), different models of paralyzed aircraft behavior (aerodynamic nature of the plane without a nose only predicted), and longitudinal radar data (radar tracks recorded from east/west position of TWA 800 from different sites). This simulation shows that after the loss of the front plane, the rest of the plane continues to be on a paralyzed flight, then climbs upward as it rolls to the left (north), rising to a maximum height between 15,537 and 16,678 feet (4,736 and 5,083 meters). ) of the last recorded height, 13,760 feet (4,190 m).
Analysis of reported witness observations
At the start of an FBI investigation, due to the possibility that international terrorists might be involved, assistance was requested from the Central Intelligence Agency (CIA). CIA analysts, relying on sound propagation analysis, concluded that the witnesses could not describe a missile approaching the plane intact, but noticed a trail of burning fuel coming from the plane after the initial explosion. This conclusion is reached after calculating how long to sound the initial explosion to reach the witness, and use it to relate the witness's observation to the order of the accident. In all cases, the witnesses could not describe a missile approaching the plane intact, because the plane had exploded before their observations began.
When the investigation took place, the NTSB decided to set up a witness group to more fully handle the reports of witnesses. From November 1996 to April 1997, the group reviewed summaries of witness reports borrowed from the FBI (with personal information edited), and conducted interviews with crew members from New York Air National Guard HH-60 helicopters and C-130 aircraft, as well as aircraft US Navy P-3 flying around TWA 800 at the time of the accident.
In February 1998, the FBI, after closing its active investigation, agreed to fully release a summary of the witnesses to the NTSB. With access to these documents no longer controlled by the FBI, NTSB formed a second group of witnesses to review the documents. Due to the amount of time elapsed (about 21 months) before the NTSB received information about the identity of the witnesses, the group of witnesses chose not to reinterview the witnesses, but instead relied on the original summary of the FBI witness statements written by FBI agents as the best available evidence of observation which were initially reported by witnesses. Although two and a half years have passed since the accident, the witness group conducted an interview with captain Eastwind Airlines Flight 507, who was the first to report a TWA 800 blast, because of his viewpoint and experience as an airline pilot..
The NTSB's review of witness documents released determined that they contained 736 witnesses, which 258 were characterized as witnesses of "light streaks" ("an object moving in the sky... various described as light dots, fireworks, flares, fallen stars, or similar. ") The NTSB Witness Group concluded that the successive light reported by witnesses may be the actual plane during its flight stages before the fireball flourished, noting that most of the 258 Consecutive light accounts were generally consistent with the flight tracks calculated from the crash aircraft after the CWT explosion.
Thirty-eight witnesses describe a beam of light rising vertically, or almost so, and this report "seems inconsistent with the flight path of an aircraft crash." In addition, 18 witnesses reported seeing a beam of light coming from the surface, or the horizon, which did not "look consistent with the flight path calculated plane and other known aspects of the crash sequence." Regarding these different reports, the NTSB notes that based on their experience in previous investigations, "witness statements are often inconsistent with known facts or with reports of other witnesses of the same event." Interviews conducted by the FBI focus on the possibility of missile attacks; suggested interview questions given to FBI agents such as "Where does the sun relate to planes and missile launch points?" and "How long did the missiles fly?" can have a biased resource response in some cases. NTSB concludes that given the large number of witnesses in this case, they "do not expect all documented witness observations to be consistent with each other" and "not seeing witness accounts seem anomalous as persuasive evidence that some witnesses may have observed a missile."
After a missile visibility test was conducted in April 2000, at Eglin Air Force Base, Fort Walton Beach, Florida, the NTSB decided that if witnesses had observed the missile strike they would see:
- the light from the burning missile motor rises very rapidly and sharply for about 8 seconds;
- light disappears up to 7 seconds;
- on missiles striking the plane and turning on CWT, another light, moving much more slowly and more laterally than the first, for about 30 seconds;
- This light descends while simultaneously evolving into a fireball falling towards the ocean. None of the witness documents describes such a scenario.
Due to their unique point of view or the level of accuracy and detail provided in their accounts, five witness accounts aroused special interest: Eastwind Airlines Flight 507 pilot, crew member in HH-60 helicopter, light-streak witness ride US Airways Flight 217, ground witness at Beach Lane Bridge in Westhampton Beach, New York, and witness on board near Great Gun Beach. Supporters of missile attack scenarios confirmed that some of these witnesses observed a missile; The analysis showed that the observations were inconsistent with missile strikes on TWA 800, but consistent with these witnesses who had observed part of the fire-fire and the sequence of breaks after the CWT explosion.
NTSB concludes that "the witness's observation of a beam of light is not related to the missile and that a beam of light reported by most witnesses is the burning of fuel from a plane crash in a paralyzed flight during several parts of the post-explosion." The NTSB further concludes that "the observation of witnesses against one or more fireballs is a wreck of a plane that falls into the sea".
Possible ignition source from middle wing fuel tank
In an effort to determine what ignites the flammable fuel vapor in the CWT and causes an explosion, the NTSB evaluates many potential ignition sources. All but one is highly unlikely to be a source of ignition.
Missile fragment or small burst charge
Although the NTSB has reached the conclusion that missile strikes do not cause structural failure of the aircraft, it is likely that the missiles could explode close enough to the TWA 800 for missile fragments to have entered the CWT and ignited the fuel/air. steam, but far enough not to leave the characteristic damage from a missile attack, is considered. Computer simulations using missile performance data simulate missiles being blown up in such a location that fragments of warheads can penetrate CWT. Based on this simulation, the NTSB concludes that it is "highly unlikely" that the warhead is detonated at such a location where a fragment can penetrate the CWT, but no other fragments affect the structure of the plane around it leaving a distinctive sign of impact.
Similarly, the investigation considers the possibility that a small explosive charge placed on the CWT could be a source of ignition. Testing by the NTSB and the British Defense Evaluation and Research Agency shows that when metals of the same type and thickness of the CWT are penetrated by small loads, there is petalling from the surface where the load is placed, pitting on adjacent surfaces, and hot gas washing damage seen in the area surrounding. Since no recoverable CWT scrap shows the characteristic of this damage, and no missing area of ​​debris is large enough to cover all expected damage, the investigation concluded that this scenario is "highly unlikely."
Other potential sources
NTSB also investigates whether the fuel/air mixture in CWT can be ignited by lightning strikes, meteor strikes, automatic ignition or ignition of hot surfaces, flames migrating to CWT from other fuel tanks through ventilation systems, uncompressed machines failure, air conditioning packages under CWT, damaged Jettison/override CWT pumps, CWT scavengers that do not work, or static electricity. After analysis, the investigation determined that these potential sources were "highly unlikely" as sources of ignition.
System of fuel quantity indication
Since the combustible fuel/air mix will always be in the fuel tank, Boeing's designers have tried to eliminate all possible sources of ignition in the 747 tank. To do so, all devices are protected from steam intrusion, and the voltage and current used by Fuel Quantity Indication System (FQIS) is kept low. In the case of the 747-100 series, the only cable located within the CWT is associated with FQIS.
In order for FQIS to be an aviation source for Flight 800, a higher than normal transfer voltage to FQIS will need to occur, as well as some mechanisms in which excess energy is released by the FQIS cable into the CWT. While the NTSB determines that factors suggesting the possibility of short-circuit events, they add that "both release mechanisms and ignition sites within the CWT can be determined from available evidence." Nonetheless, the NTSB concludes that "the ignition energy for CWT explosions is likely to enter CWT via FQIS cable".
Although FQIS itself is designed to prevent hazards by minimizing voltages and currents, the inner tube of the FQIS Flight 800 compensator shows similar damage to the compensator tube identified as a source of ignition for a spike fire tank that destroyed 747 near Madrid in 1976. It is not considered a proof of ignition source. Proof of the arc is found in a wire bundle which includes a FQIS cable that connects to the center wing tank. Arcing signs are also seen on two cables sharing the cable raceway with FQIS cable at station 955.
The captain's cockpit voice recorder channel shows two "breaks" of the background power harmonics in the second before the recording ends (with the separation of the nose). This may be a sign of an arc on the cockpit cable adjacent to the FQIS cable. The captain commented on the "crazy" readout of the engine fuel flow gauge number 4 about 2 1/2 minutes before the CVR recording ended. Finally, the Central Wing Tank fuel quantity recovered and showed 640 pounds instead of the 300 pounds that had been loaded into the tank. Experiments show that the use of power to the cable leading to a fuel quantity meter may cause the digital display to change several hundred pounds before the circuit breaker journey. Thus the measuring anomaly can be caused by the short FQIS cable. NTSB concludes that the most probable source of sufficient voltage to cause ignition is short of the damaged cable, or inside the electrical components of the FQIS. Because not all components and cables are restored, it is impossible to determine the required voltage source.
Conclusion
The NTSB investigation ended with the adoption of the final report on August 23, 2000. In it the Council determined that the probable cause of the TWA 800 accident was:
[An] explosion of the central wing fuel tank (CWT), which results from ignition of a combustible fuel/air mixture inside the tank. The source of ignition energy for explosion can not be determined with certainty, but, from the source evaluated by the investigation, the most likely is a short circuit outside the CWT that allows excess voltage to enter through the fuel cable associated with the fuel. quantity indication system.
In addition to possible causes, NTSB finds the following factors for the cause of the accident:
- The concept of design and certification that fuel tank explosions can be prevented only by blocking all sources of ignition.
- Boeing 747 certification with a heat source located under the CWT without means to reduce the heat transferred to the CWT or to make the fuel tank vapor is not flammable.
During its investigation, and in its final report, the NTSB issued fifteen safety recommendations, mostly including fuel tanks and cable related issues. Among the recommendations is that significant consideration should be given to the development of modifications such as inerting nitrogen systems for the design of new aircraft and, where applicable, for existing aircraft.
Controversy
NTSB's conclusions about the causes of the TWA 800 disaster take four years and one month to be published. The FBI's earliest investigations and interviews, which were later used by the NTSB, were conducted under the assumption of a missile attack, a fact recorded in the NTSB final report. Six months into the investigation, NTSB chairman, Jim Hall, was quoted as saying, "All three theories - bombs, missiles, or mechanical failures - remain." Speculation is driven in part by the initial, visual and eyewitness descriptions of a catastrophe that shows a sudden explosion and a trail of fire moving towards the top.
On July 17, 2013, the 17th anniversary of the tragedy, the Epix premium TV channel aired the documentary TWA Flight 800 , which alleges that the accident investigation was a cover. The film highlights extensive eyewitness interviews, with many people interviewed who directly object to the publicly portrayed versions of their own event description. It also highlighted interviews with investigators involved in preliminary investigations, six of whom petitioned to reopen the investigation. Their petition is based on eyewitness accounts, radar evidence demonstrating missile probability and claims of evidence interference. They called it the "TWA 800 Project". Former investigator NTSB Henry Hughes has been quoted that he believes a bomb or missile caused the accident.
To consider a petition, the NTSB gathers a team of investigators who were not previously involved with the original investigation. On July 2, 2014, the NTSB said it would not reconsider its findings that the accident was caused by an explosion of fuel tanks. In their press release stated: "After a thorough review of all information provided by the petitioners, NTSB rejected the request entirely because the evidence and analysis presented did not show original findings incorrect."
Aftermath
Many internet users respond to the incident; Web traffic results set the record for internet activity at the time. CNN traffic increased fourfold to 3.9 million visits per day. After the tragedy, the website The New York Times saw an increase in traffic to 1.5 million clicks per day, 50% higher than previous rates. In 1996, several US government websites were updated daily, but the United States Navy crash website was constantly updated and had detailed information on the rescue of the crash site.
The ruins were permanently stored at the NTSB facility in Ashburn, Loudoun County, Virginia built specifically for the purpose. Reconstructed aircraft are used to train accident investigators.
On July 18, 2008, the Transportation Secretary visited the facility and announced a final rule designed to prevent accidents caused by fuel tank explosions. The rule would require airlines to pump inert gases into the tank, and would include a central wing tank on all new passengers and cargo planes, and passenger aircraft built in most of the 1990s, but not old cargo planes. The NTSB first recommended such a rule only five months after the incident and 33 years after similar recommendations were issued by the Council of Civil Aviation Security Council on December 17, 1963, nine days after the Pan Am 214 Flight crash.
The Accident TWA Flight 800, and the previous ValuJet 592 Flight in 1996, prompted Congress to pass the Aviation Family Disaster Relief Act of 1996 as part of a federal aviation allocation bill. Among other things, the Act provides NTSB, rather than the specific airlines involved, the responsibility to coordinate services to families of victims of fatal plane crashes in the United States. In addition, he limits lawyers and others to contact family members within 30 days of an accident.
During the investigation, the NTSB and the FBI clashed with each other many times. The agency needs a detailed protocol explaining which agency leads when it was initially unclear whether an event was an accident or a crime. 49 Federal Code of Regulation 831.5 set forth in 1996 (as it happens now) that the NTSB flight accident investigation has priority over all other federal investigations. After an investigation of 800 TWA flights, the NTSB recognizes the need for better clarity. NTSB searched and secured the language to clarify the problem in 49 USC 1131 (a) (2) (B), which was amended in 2000 to read:
In 2005, the NTSB and the FBI signed a Memorandum of Understanding (MOU) stating that, "immediately after the transport accident, the NTSB is the principal investigative agency alleged and will take control of the crash site." The FBI may still conduct a criminal investigation, but the NTSB investigation has priority. When the priority of investigation remains with the NTSB, the FBI should coordinate its investigative activities with responsible NTSB investigators. This authority includes interviewing witnesses. The MOU states that: "[t] the procedure is intended... to ensure that neither the NTSB nor the FBI investigation activities need to complicate or interfere with the investigation of other institutions.The new legal language and MOU have improved coordination between the NTSB and the FBI since the 800 TWA flight crash. FBI and NTSB personnel conduct joint exercises. They can call each other's laboratories and other assets. The NTSB and FBI have appointed liaison to ensure that information flows between agencies, and to coordinate on-site operations.
Heidi Snow, fiancé of the TWA800 victims Michel Breistroff, founded the AirCraft Air Emotional Support (ACCESS) nonprofit group with the families of Pan Am Flight 103 victims.
International Warning
The TWA Flight 800 International Memorial is dedicated in a 2-acre (8,100 m 2 ) package adjacent to the main pavilion at Smith Point County Park in Shirley, New York, on July 14, 2004. The warning is located in 40.734509 Â ° N 72.860372 Â ° W / 40.734509; -72.860372 . The funds for the memorial were raised by the TWA Flight 800 Family Association. David Busch of Busch Associates in Bay Shore, New York designed the memorial. The memorials include landscaped lands, flags from 13 victim countries, and a warped black Granite granite memorial with names engraved on one side and illustrations on the other side of the waves that release 230 seagulls. In July 2006, an abstract design of a 10-foot-tall (3.0 m) lighthouse in black granite designed by Harry Edward Seaman, who had lost his cousin in the accident, was added. The lighthouse was on a tomb that housed many of the victims' personal belongings. The 567 Air Force Band of Northeast plays dedication, setting the Brahms "Blessed are They" while all the names of the victims are read out.
Passenger and crew
There are 230 people on board TWA 800 including 18 crews and 20 unmanned employees, most of whom are crews intended to close Paris-Rome flights.
Of the 230 people in it are people from the United States, Mexico, France, Denmark, Belgium, Algeria, Israel, Portugal, Germany, Italy, Norway, Sweden and England.
Dead passengers include:
- Michel Breistroff, French hockey player
- Marcel Dadi, French guitarist
- David Hogan, American composer
- Jed Johnson, Andy Warhol's twelve-year-old partner, interior designer and film director in 1977 Andy Warhol's Bad
- Pam Lychner, advocate for the rights of American crime victims and former TWA flight attendant
- Rico Puhlmann, German fashion photographer
In addition, 16 students and 5 adult companions from the Montoursville Area High School France club participated.
See also
- Philippine Airlines Flight 143 - A similar incident involving 737, suffered a fuel tank explosion on the ground, possibly caused by a faulty cable
- Pan Am Flight 214 - A plane that experienced an explosion of fuel tank in the air, after being hit by lightning
- Night Fall (novel) - 2004 New York Times Best Seller that tells about the couple who witnessed and recorded the accident TWA Flight 800
- Louis Freeh - Director of the FBI from 1993 - 2001 who assisted in the investigation of the accident
Note
References
External links
- National Transportation Safety Board
- NTSB Aircraft Crash Report
- NTSB Aircraft Crash Report Appendix A-C
- NTSB Aircraft Crash Report Appendix D-G
- TWA 800 (Archive) Board Meeting
- Report by John Barry Smith (Archive), posted on the NTSB website
- CIA analysis of witness observations
- TWA Flight 800: United States Navy (Archive)
- Trans World Airlines Flight 800: The Federal Bureau of Investigation of the New York Field Office (Archive)
- Boeing Statement Following First Day of NTSB's Flight 800 Sunshine Meeting - Boeing
- Learn from Tragedy: Explosion and Flight 800
- CNN Portal: TWA Flight 800
- "Passenger List: Flight TWA 800". The Washington Post .
- TWA Flight 800 Victims: Who are They?
- "After Crash" - Houston Press
- N93119 was filmed in 1991, 5 years before the accident (courtesy Ryan Bomar)
- The documentary "TWA Flight 800" 7/16/13 NYTimes reviewing the trailer link
- TWA Flight 800 on IMDb (the movie mentioned in the link above ^)
Source of the article : Wikipedia
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