Although flying the friendly skies is statistically the safest way to travel, the feeling of helplessness that comes when there's any hint of danger is quite unsettling. Most frequent flyers have been on planes that encountered at least moderate turbulence, for example, and despite the fact that it's not as dangerous as, say, an engine malfunction, most people can't help but brace themselves for the worst possible outcome. Now imagine that experience times ten, with an unpredictable hijacker who's hell-bent on making a political point to the world. Such dire situations can be difficult for the crew, passengers and law enforcement to handle, as evidenced by the incidents listed below. Excluding the unforgettable 9/11 attacks, these hijackings were among the most terrifying in the history of air transportation.

1. El Al Flight 426 (1968): El Al Airlines, based in Israel, has always been a target for prospective hijackers. For that reason, it has taken thorough measures in recent decades to ensure passenger safety, and as a result, it's one of the safest airlines around. Its biggest blemish, one that changed its procedures for the better, occurred when Flight 426 was commandeered by three members of the Popular Front for the Liberation of Palestine (PFLP). Initially traveling from London to Rome, the plane was diverted to Algiers, where war had been declared on Israel a year earlier. All Non-Israeli passengers were released, leaving 12 Israeli passengers — 10 women and children were released at the end of the week — and the crew of 10. It took 40 days of negotiations to reach an agreement, and everyone — including the hijackers — were freed. A conflict between Israel and Algiers could've resulted without a resolution.
2. Dawson's Field Hijackings (1970): In a single day, four planes were simultaneously seized by the PFLP gunmen, who forced two to fly to Dawson's Field in the Jordanian desert. All 310 passengers were freed, but Jewish passengers and the flight crews consisting of 56 members were kept behind. Expecting a hostile effort to free the hostages, the PFLP blew up the empty planes, demanding the release of the body of Patrick Arguello and the detained Leila Khaled, both of whom failed in their attempt to hijack El Al Flight 219. Conditions were met, and a conflict ensued between Hashemite King Hussein of Jordan and Palestinians known as Black September.
3. Air France Flight 139 (1976): Six years after the Dawson's Field incident, two members of the PFLP and two members of German Revolutionary Cells took control of Air France Flight 139 en route from Athens to Paris and diverted it to Benghazi, Libya. After releasing a female hostage who was pretending to have a miscarriage, the 247 remaining passengers and crew of 12 were taken to Entebbe Airport in Uganda, where four more hijackers joined the effort. Demanding the release of 40 Palestinians detained in Israel and 13 in other countries, they threatened to kill hostages if they were ignored. Operation Entebbe followed, as 100 elite commandos from Israel traveled to the site and stormed the scene amid a haze of gunfire to rescue the hostages. When the smoke cleared, three passengers, an Israeli commando and 45 Ugandan soldiers were killed. One passenger who was at the hospital was later murdered. Overall, 105 passengers were saved.
4. Lufthansa Flight 181 (1977): Destined from Palma de Mallorca to Frankfurt Lufthansa with 86 passengers and five crew members aboard, Lufthansa Flight 181 was hijacked in midair by four militant Palestinians — members of the PFLP — who called themselves "Commando Martyr Halime." One invaded the cockpit with a pistol and demanded the flight to Larnaca, Cyprus , but it was diverted to Rome due to insufficient fuel. After traveling to Cyprus, Bahrain, Dubai and Aden, it settled in Mogadishu, and Operation Feuerzauber, primarily undertaken by West German counter-terrorism group GSG 9, resulted in a hostile raid of the plane and the killing of two hijackers and the injuring of the others, one of whom was mortally wounded. All 86 passengers survived.
5. Malaysia Airlines Flight 653 (1977): The hijacking of Malaysia Airlines Flight 653 remains a mystery more than three decades later. Not long after departing Penang for Kuala Lumpur, Captain G.K. Ganjoor reported an "unidentified hijacker" was aboard and later reported they were "proceeding to Singapore." Eventually all communication was lost, and the plane crashed in Kampong Ladang, Tanjong Kupang, killing all seven crew members and 93 passengers, including Malaysian Public Works Department Head Dato' Mahfuz Khalid, Malaysian Agricultural Minister Dato' Ali Haji Ahmadand, and Cuban Ambassador to Japan Mario Garcia. Some suspected that a member of the Japanese Red Army was to blame, though no evidence exists to prove it.
6. TWA Flight 847 (1985): Six members of Hezbollah and Islamic Jihad were responsible for the infamous two-week ordeal involving TWA Flight 847. En route from Athens to Rome, the plane was overtaken just after takeoff and diverted to Beirut, where 19 passengers were released, and Algiers, where 20 passengers were released. The plane returned to Beirut, and the hijackers proceeded to single out United States Navy Seabee diver Robert Stethem, beat him, fatally shoot him and dump his body onto the ramp. Seven American passengers with Jewish-sounding names were removed from the plane and held hostage elsewhere in Beirut. The plane traveled back to Algiers, released 65 passengers, and returned to Beirut. The hijackers made several demands, including the release of the "Kuwait 17" involved in the 1983 bombing of the U.S. embassy in Kuwait and international condemnation of the U.S. and Israel. Eventually, the 40 remaining hostages were released and nobody else was harmed.
7. EgyptAir Flight 648 (1985): Remembered as one of the world's bloodiest and scariest plane hijackings, the events aboard EgyptAir Flight 648 will forever serve as a reminder of how not to deal with terrorists. After three Palestinian members of the Abu Nidal Organization took control of the plane destined from Athens to Cairo, an Egyptian Security Service member opened fire, killing one of the hijackers. In return, he was shot dozens of times and killed. As a result of the exchange of bullets, the fuselage of the plane was punctured, and the pilot was forced to descend so that everyone on board could breathe. Low on fuel, the plane landed in Malta against the wishes of Maltese authorities, and a stand-off commenced. Eleven passengers and two injured flight attendants were released, but Maltese Prime Minister Karmenu Mifsud Bonnici's hard-line approach resulted in the execution of two American passengers. Egyptian commandos later stormed the plane, causing a chaotic, fiery scene — from either the explosives from the commandos or grenades from the terrorists — in which 56 of the 88 remaining passengers were killed. Sixty of the 92 passengers initially on board were killed.
8. Pan Am Flight 73 (1986): While preparing to depart for Frankfurt from Karachi, Pakistan, four members of the Abu Nidal Organization, dressed as Karachi airport security guards, hijacked Pan Am Flight 73. The crew immediately escaped through an overhead hatch in the cockpit, grounding the plane. In response, an Indian-American passenger was executed after demands that the crew return to the plane weren't met. Later, as the plane sat in darkness without power and Pakistani authorities prepared to storm in, a grenade was tossed and random shooting began. In the end, 20 passengers will killed, but many escaped due in part to the heroics of 22-year-old flight purser Neerja Bhanot, who helped them off the plane and shielded three children from bullets.
9. Iraqi Airways Flight 163 (1986): Air safety was a major concern in the Middle East in the mid-1980s, as deadly hijackings were becoming more common — see the previous three paragraphs. Iraqi Airways Flight 163, traveling from Baghdad to Amman with 91 passengers and 15 crew members, was taken by four men affiliated with Hezbollah. Security personnel immediately attempted to neutralize them, but they responded by detonating grenades in the passenger cabin and cockpit, causing the plane to crash near Arar, Saudi Arabia. Sixty passengers and three crew members died.
10. Ethiopian Airlines Flight 961 (1996): Captured on camera by a South African honeymooner on a beach in the Comoros Islands, the video of the descent and crash of Ethiopian Airlines Flight 961 stunned the world. It was hijacked by three nervous and disorganized Ethiopians who were seeking political asylum in Australia. Knowing he didn't have enough fuel to make such a trip, Captain Leul Abate traveled toward the Comoros Islands, hoping to find an available runway. When both engines failed, he was unable to locate Prince Said Ibrahim International Airport and was forced to ditch in shallow waters. Numerous residents and tourists swam to the aid of the passengers. Even still, the ordeal was costly, as 122 of the 172 passengers and crew members died.