There also have been several attempts to blow up planes headed to the United States and other plots involving explosives and airliners though the years. Several of the plots involve al Qaeda in the Arabian Peninsula, the terrorist network's affiliate in Yemen.
Seven people were on board a United Airlines flight that originated in Newark, New Jersey, and, after a stop in Cleveland, was on its way to Chicago. As it passed over the Indiana town of Chesterton, residents heard a boom. At first people thought it might have been lightning that brought the plane down but evidence pointed toward a bomb planted in the back of the plane, near the lavatory. No suspect was ever named.
May 1962: Suicide by dynamite
Continental Airlines Flight 11 becomes the first U.S. commercial passenger jet to be blown up. It was taking 45 people from Chicago to Los Angeles (with a stop in Kansas City). Investigators fingered Thomas Doty, who purchased hundreds of thousands of dollars' worth of life insurance policies before he lit six sticks of dynamite while in the bathroom.
June 1985: Deadliest bombing
A total of 329 people were killed on Air India Flight 182, the deadliest commercial aviation bombing. It was traveling from Toronto to Mumbai (stops in Montreal, London and Delhi) when it disappeared south of Ireland. The bomb went off in a cargo hold while the plane was at 31,000 feet. Both Sikh and Kashmiri terrorists were blamed for the attack. Injerjit Singh Reyat, a Sikh, was the only person convicted. He pleaded guilty to a manslaughter charge but also was later convicted of perjury in another trial.
December 1988: Tragedy over Lockerbie
About 38 minutes after it took off from London, Pan Am Flight 103 was flying at 31,000 feet when a bomb hidden in a Toshiba cassette recorder inside a suitcase exploded. The 259 people on the plane and 11 people on the ground in Lockerbie, Scotland, were killed.
The United States and United Kingdom blamed Abdelbaset Ali Mohmed al Megrahi, who was once security chief for Libyan Arab Airlines, and Al Amin Khalifa Fhimah -- accusing them both of being Libyan intelligence agents. Libya eventually handed over both men to the United Nations in 1999 and later pay $2.7 billion to victims' families. Megrahi was convicted while Fhimah was acquitted. In October 2015, Scottish officials announce two unidentified Libyans were new suspects.
November 1989: Pablo's thugs blow up airliner
Drug kingpin Pablo Escobar and the Medellin drug cartel were blamed for the explosion that caused the crash of Avianca Flight 203. The Boeing 727 left Bogota, Colombia, on a flight to Cali, but a bomb in the cabin and a secondary explosion kill 107 people.
Most accounts say the intended target, presidential candidate Cesar Gaviria, changed his plans at the last minute and was not on the plane. Other reports said one of Escobar's top assassins, Dandeny Munoz-Mosquera, arranged the bombing to kill two informants. Because two Americans were killed, the U.S. prosecuted and convicted Munoz-Mosquera on murder charges after he was arrested in New York.
August 2004: Twin bombings
Two Russian airliners were destroyed by midair bombs on August 24. Eighty-nine people died in the crashes, and a few days later, Russia's security service blamed the explosions on terrorists. According to Russian news agencies, two Chechen women became the focus of suspicion. Investigators confirmed traces of hexogen were found in the wreckage. Hexogen, when mixed with nitroglycerin, forms a plastic explosive similar to C4 and had been used by Chechen rebels in attacks on Russian soil.
January 1995 : 'Project Bojinka'
Ramzi Yousef, Abdul Hakim Murad and Wali Khan Amin Shah plotted to blow up 12 U.S. airliners originating from the Philippines and elsewhere in East Asia. The planes were to explode over the Pacific Ocean in a plot called "Project Bojinka." Yousef was convicted in 1996 for the plot and for planting a test bomb on a Philippines Airlines jet bound for Tokyo on December 11, 1994.
He boarded the airliner in Manila under an assumed name, put the device under a seat and left the plane during a layover. The bomb exploded during the next leg of the flight, killing one passenger and injuring 10 others, but the plane remained intact and was able to make an emergency landing in Okinawa, Japan. Yousef was also convicted of the 1993 bombings at the World Trade Center in New York that killed six people.
December 2001: Shoe bomber
Richard Reid, a heavily traveled British citizen of Jamaican heritage, was accused of trying to light explosives in his sneakers with a match aboard American Airlines Flight 63 from Paris to Miami on December 22. Flight attendants and passengers prevented him from doing so, and the plane was diverted to Boston with a military escort. No one on the plane is hurt.
August 2006: Trans-Atlantic plot
Two weeks before the plot was to be launched, British officials arrested 24 people in a plan to bring down airliners traveling from Heathrow Airport in London to the United States. The plot involved hiding liquid explosives in soft-drink bottles, and as many as 10 flights would have been targeted, U.S. officials said. Ten men, including ringleader Abdulla Ahmed Ali and bomb chemist Assad Sarwar, were convicted. A few days before his arrest, Ali was monitored looking up flights from Heathrow to North America that would be in the air at the same time.
December 2009: Underwear bomber
Umar Farouk AbdulMutallab tried to blow up a Northwest Airlines flight carrying 290 people from Amsterdam, Netherlands, to Detroit on Christmas Day with explosives placed in his underwear. The device failed to detonate fully, instead setting off a fire at his seat.
The bomb components allegedly included Pentaerythritol (also known as PETN, a high explosive), as well as Triacetone Triperoxide (also known as TATP, a high explosive) and other ingredients. He was subdued and restrained by the passengers and flight crew after trying to detonate the bomb. The airplane landed shortly thereafter, and he was taken into custody by U.S. Customs and Border Protection officers. Authorities linked AbdulMutallab to al Qaeda in the Arabian Peninsula
October 2010: Printer toner bombs
Authorities in the United Arab Emirates and Britain found two explosive-laden packages sent from Yemen that were addressed to synagogues in Chicago. The devices, loaded with the PETN, are packed in computer printer toner cartridges and designed to be detonated by a cell phone, a U.S. source close to the investigation said.
Another U.S. official said the devices found in the packages were very sophisticated and could have exploded in flight, but it wasn't clear whether that was the intent. Al Qaeda in the Arabian Peninsula claimed responsibility.
May 2012: AQAP tries another bomb
U.S. and other intelligence agencies broke up a plot by terrorists in Yemen to slip a bomb past airport metal detectors and onto an airplane bound for the United States. The bomb was seized before it made it to an airport and posed no real threat to air travelers.
It was similar to, but more sophisticated than, the device discovered in a failed attempt to bring down a Detroit-bound airliner on Christmas Day in 2009. The bomb also appeared to be the work of al Qaeda in the Arabian Peninsula, U.S. officials say.