Itavia Flight 870

On 27 June 1980, Itavia Flight 870 (IH 870, AJ 421), a McDonnell Douglas DC-9 passenger jet en route from Bologna to Palermo, Italy, crashed into the Tyrrhenian Sea between the islands of Ponza and Ustica, killing all 81 people on board. Known in Italy as the Ustica massacre ("strage di Ustica"), the disaster led to numerous investigations, legal actions and accusations, and continues to be a source of controversy, including claims of conspiracy by the Italian government and others. The Prime Minister of Italy at the time, Francesco Cossiga, attributed the crash to being accidentally shot down during a dogfight between Libyan and NATO fighter jets. A 1994 report argued the cause of the crash was a terrorist bomb, one in a years-long series of bombings in Italy. On 23 January 2013, Italy's top criminal court ruled that there was "abundantly" clear evidence that the flight was brought down by a missile, but the perpetrators are still missing.
Aircraft.
The aircraft, a McDonnell Douglas DC-9-15 flown as Aerolinee Itavia Flight 870, was manufactured in 1966 and acquired by the airline on 27 February 1972 with the serial number CN45724/22 and registration I-TIGI (formerly N902H, operated by Hawaiian Airlines).
Flight history.
On 27 June 1980 at 20:08 CEST, the plane departed with a delay of one hour and 53 minutes from Bologna Guglielmo Marconi Airport for a scheduled service to Palermo Punta Raisi Airport, Sicily. With 77 passengers aboard, Captain Domenico Gatti and First Officer Enzo Fontana were at the controls, with two flight attendants. The flight was designated IH 870 by air traffic control, while the military radar system used AJ 421.
Contact was lost shortly after the last message from the aircraft was received at 20:37, giving its position over the Tyrrhenian Sea near the island of Ustica, about southwest of Naples. At 20:59 CEST, the aircraft broke apart in mid-air and crashed.
Two Italian Air Force F-104s were scrambled at 21:00 from Grosseto Air Force Base to locate the accident area and search for any survivors, but failed to do so because of poor visibility.
Floating wreckage and bodies were later found in the area. There were no survivors among the 81 people on board.
Official investigation.
After years of investigation, no official explanation or final report has been issued by the Italian government. In 1989, the Parliamentary Commission on Terrorism, headed by Senator Giovanni Pellegrino, issued an official statement concerning the crash of Flight 870, which became known as the "Ustica Massacre" ("Strage di Ustica").
The investigation stage of the case has suggested that:
The perpetrators of the crime remain unidentified. The court, unable to proceed further, closed the case.
In July 2006, the re-assembled fragments of the DC-9 were returned to Bologna from Pratica di Mare Air Force Base near Rome.
In June 2008, Rome prosecutors reopened the investigation into the crash after former Italian President Francesco Cossiga (who was prime minister when the incident occurred) said that the aircraft had been shot down by French warplanes. On 7 July 2008, a claim for damages was served on the French President.
High treason charges against Italian Air Force officers.
The role of Italian Air Force personnel in the tragedy is unclear. Several Air Force officers have been investigated and tried for a number of alleged offences, including falsification of documents, perjury, abuse of office and aiding and abetting. Four generals were charged with high treason, on the allegations that they obstructed government investigation of the accident by withholding information about air traffic at the time of Ustica disaster.
The first ruling, on 30 April 2004, pronounced two of the generals, Corrado Melillo and Zeno Tascio, not guilty of high treason. Lesser charges against a number of other military personnel were also dropped. Other allegations could no longer be pursued after the expiration of the statute of limitations, since the disaster had occurred more than 15 years before. For this same reason, no action could be taken against the other two generals, Lamberto Bartolucci and Franco Ferri. However, the ruling did not acquit them, and they were still alleged to be guilty of treason. In 2005, an appeals court ruled that no evidence supported the charges. On 10 January 2007, the Italian Court of Cassation upheld this ruling and conclusively closed the case, fully acquitting Bartolucci and Ferri of any wrongdoing.
In June 2010, Italian President Giorgio Napolitano urged all Italian authorities to cooperate in the investigation of the incident.
In September 2011, a Palermo civil tribunal ordered the Italian government to pay 100 million euros ($137 million) in civil damages to the relatives of the victims for failing to protect the flight, concealing the truth and destroying evidence.
On 23 January 2013, the Civil Cassation Court ruled that there was "abundantly" clear evidence that the flight was brought down by a stray missile, confirming the lower court's order that the Italian government must pay compensation.
In April 2015, an appeals court in Palermo confirmed the rulings of the 2011 Palermo civil tribunal and dismissed an appeal by the state attorney.
Hypotheses on the causes.
Speculation at the time and in the years since has been fueled in part by media reports, military officials' statements and ATC/CVR recordings. Adding to the widespread conjecture was the observation of radar images showing trails of objects moving at high speeds.
Terrorist bomb.
After the series of bombings that hit Italy in the 1970s, a terrorist act was the first explanation to be proposed. As the flight was delayed in Bologna by almost three hours, a bomb's timer may have been set to actually cause an explosion at the Palermo airport, or on a further flight of the same plane. The technical commission supporting a 1990 judicial enquiry reported that an explosion in the rear toilet, and not a missile strike, was the only conclusion supported by the wreckage analysis.
In 1994, Frank Taylor, an independent accident investigator, found evidence of a bomb explosion in the rear lavatory. A large section of the aircraft's fuselage around the lavatory was never recovered (presumably having disintegrated in the explosion). A test explosion in a DC-9 lavatory showed the resulting deformation in the surrounding structure to be almost identical to that of the incident aircraft.
Missile strike during military operation.
Major sources in the Italian media have alleged that the aircraft was shot down during a dogfight involving Libyan, United States, French and Italian Air Force fighters in an assassination attempt by NATO members on an important Libyan politician, perhaps even Libyan leader Muammar al-Gaddafi, who was flying in the same airspace that evening. This version was supported in 1999 by investigative magistrate Rosario Priore, who said in his concluding report that his investigation had been deliberately obstructed by the Italian military and members of the secret service, in compliance with NATO requests.
According to the Italian media, documents from the archives of the Libyan secret service passed on to Human Rights Watch after the fall of Tripoli show that Flight 870 and a Libyan MiG were attacked by two French jets.
On 18 July 1980, 21 days after the Aerolinee Itavia Flight 870 incident, the wreckage of a Libyan MiG-23, along with its dead pilot, was found in the Sila Mountains in Castelsilano, Calabria, southern Italy, according to official reports.
Conspiracy theories.
Several conspiracy theories explaining the disaster persist. For example, the vessel that carried out the search for debris on the ocean floor was French, but only US officials had access to the aircraft parts they found. 
Several radar reports were erased and several Italian generals were indicted 20 years later for obstruction of justice. The difficulty the investigators and the victims' relatives had in receiving complete, reliable information on the Ustica disaster has been popularly described as "un muro di gomma" (literally, a rubber wall), because investigations just seemed to "bounce back".
Memorial.
On 27 June 2007, the Museum for the Memory of Ustica was opened in Bologna. The museum is in possession of parts of the plane, which are assembled and on display, including almost all of the external fuselage. The museum also has objects belonging to those on board that were found in the sea near the plane. 
Christian Boltanski was commissioned to produce a site-specific installation.
The installation consists of:
Each loudspeaker describes a simple thought/worry (e.g. "when I arrive I will go to the beach")
All the objects found are contained in a wooden box covered with a black plastic skin.
A small book with the photos of all objects and various information is available to visitors upon request.
Dramatization.
The accident was featured in the 13th season of the Canadian documentary series "Mayday" in an episode entitled "Massacre over the Mediterranean". The film discusses the three separate technical investigations that occurred and the extent of public pressure for the investigation to be completed. The film judged that the third and final technical investigation, which concluded that the wreckage ruled out a missile and pointed to an explosion in or near the rear lavatory was the most likely.
The dramatization included comments critical of the Italian judiciary's failure to officially release the third technical investigation to the public, or to consider its conclusion that missiles were not responsible. Interviewee David Learmount of Flight International expressed a number of personal opinions:
Frank Taylor, a British investigator involved in the third technical inquest, was interviewed for the dramatization:
"We discovered quite clearly that somebody had planted a bomb there, but nobody on the legal side, it would appear, believed us and therefore, so far as we are aware, there has been no proper search for who did it, why they did it, or anything else. As an engineer and an investigator I cannot see why anybody would want to consider anything other than the truth".
However, the findings from Frank Taylor's report have been heavily criticised by either the investigative magistrate Rosario Priore and several members of the Italian press. In particular it was criticised as failing to explain how there was no damage to the recovered lavatory and the toilet, as they were found practically intact, as well as with no evidence of any of the damage or residues that otherwise a bomb would have caused, as certified by tests performed during the 1994 investigation by the Defence Research Energy laboratory in England.
In addition the "Massacre over the Mediterranean" dramatization has raised negative comments in Italy from a wider part of the public, the press and the "Associazione dei Parenti della Vittime della strage di Ustica" (Ustica disaster Victim's relatives Association) for the superficiality of the analysis and the conclusions and the inaccuracies portrayed in the program, as well as David Learmount's highly derogatory remarks towards Italy and its judicial system.
A 1991 Italian film by Marco Risi, "The Rubber Wall", tells the story of a journalist in search of answers to the many questions left open by the accident. The film theorises on a few possible scenarios, including the possibility that the DC-9 was mistakenly shot down during an aerial engagement between NATO and Libyan jet fighters.