Incendiary balloon

SMS Vulcano at Pula in 1879, this ship, acting as a balloon carrier, launched the first naval aviation attack in 1849 against Venice

In 1792, Joseph-Michel Montgolfier proposed using balloons to drop bombs on British forces and ships in Toulon.[1]

In 1807, Denmark attempted to construct a hand-propelled dirigible that would bomb British ships blockading Copenhagen from the air.[2]

In 1846 a British board rejected as impractical a bombing design by Samuel Alfred Warner.[3] Attempts by Henry Tracey Coxwell to interest the British government a few years later were rejected as well.[3]

In 1847, John Wise proposed the use of balloon bombs in the Mexican–American War.[1]

The first aggressive use of balloons in warfare took place in 1849 during the First Italian War of Independence.[4][5] Austrian imperial forces besieging Venice attempted to float some 200 paper hot air balloons, each carrying a 24-to-30-pound (11 to 14 kg) bomb that was to be dropped from the balloon with a time fuse over the besieged city. The balloons were launched mainly from land; however, some were also launched from the side-wheel steamer SMS Vulcano that acted as a balloon carrier. The Austrians used smaller pilot balloons to determine the correct fuse settings. At least one bomb fell in the city; however, due to the wind changing after launch, most of the balloons missed their target, and some drifted back over Austrian lines and the launching ship Vulcano.[2][3][6]

During World War II, the British Operation Outward launched some 99,142 balloons at Germany, 53,543 of which were carrying incendiaries, the other 45,599 carrying trailing wires to damage high voltage lines.[7]

In 1944–1945, during World War II, Japan launched some 9,300 Fu-Go balloon bombs at North America. The 10-meter (33 ft) diameter balloons were inflated with hydrogen and typically carried one 15 kilograms (33 lb) bomb, or one 12 kilograms (26 lb) bomb along with four 5 kilograms (11 lb) bombs.[8] The Fu-Go utilized the 220 miles per hour (350 km/h) winter jet stream to cross 5,000 miles (8,000 km) of the Pacific Ocean in approximately three days. To control altitude, the balloon used a barometric sensor that would release ballast sand-bags when the balloon went below 30,000 feet (9,100 m). When the sensor registered an altitude of above 38,000 feet (12,000 m), hydrogen was vented from the balloon. The whole mechanism was activated 52 minutes after launch to allow the balloon to reach initial altitude. The final sandbag stations were fitted with incendiary bombs which were released by the same mechanism, and after the last release the balloon activated a self-destruct mechanism and released an additional bomb.[9]

The balloons were launched in the winter to take advantage of the more favorable winter jet stream. However this limited their damage potential as wildfires were less likely to catch in winter.[10][11] The Fu-Go balloons inflicted relatively little damage, except for one fatal incident in which a woman and five children were killed near Bly, Oregon after they approached a balloon that had landed at the subsequently named Mitchell Recreation Area.[6][12] The deaths of six civilians were the only fatalities caused by fire balloons on American soil during World War II.[13]

Following World War II, the United States developed the E77 balloon bomb based on the Fu-Go balloon. This balloon was intended to disperse an anti-crop agent, but it was not used operationally.[14][15] The 1954–1955 WS-124A Flying Cloud program tested high-altitude balloons for the delivery of weapons of mass destruction, but they were found infeasible because of their inaccuracy.[16]

Helium balloons bearing flammable materials launched from Bureij in the Gaza Strip

Since the beginning of the 2018 Gaza border protests, Palestinians have been launching incendiary kites at Israel as a form of agro-terrorism. Since the beginning of May 2018,[17] helium-filled incendiary balloons have been used alongside the kites.[18][19][20] Gazan balloons are devised from helium-filled party balloons or condoms that are strung together, with flaming rags, other incendiary devices, or explosives strung below.[21][22] The prevailing wind blowing in from the Mediterranean Sea, propels the balloons inland from Gaza into Israel.[23][24]

According to a report in Ynet, as of 10 July 2018, incendiary kites and balloons started 678 fires in Israel, burning 910 hectares (2,260 acres) of woodland, 610 hectares (1,500 acres) of agricultural crops, as well as open fields.[25] Some balloons landed in the Eshkol Regional Council[26] and the Sdot Negev Regional Council, and no one was injured.[27] One balloon cluster reached Beersheba, some 40 kilometres (25 mi) from the Gaza strip.[28][29]