In this aerial view the officers' building and an auditorium stand at the former Soviet military base on January 26, 2017 in Wuensdorf, Germany. Wuensdorf, once called “The Forbidden City”, was the biggest base for the Soviet armed forces in communist East Germany from 1945 until the last Soviet troops left in the early 1990s following the end of the Cold War and the reunification of Germany. (Photo by Sean Gallup/Getty Images)

Life as tenant farmers in Kasungu, northern Malawi, can be a struggle for families trapped in poverty, who feel forced to rely on their children’s help, impacting schooling. Here: A tobacco field at a farm in Kasungu region, Malawi. Tobacco is the country’s most important export crop, with tobacco leaf from Malawi filling cigarettes found all over the world. Here: Tiyamike Phiri hopes to become a nurse because she wants to travel the country and help others. (Photo by David Levene/The Guardian)

Flowers are placed on a “comfort woman” statue during the weekly Wednesday protest in front of Japanese embassy demanding for an apology and compensation from Japanese government in Seoul, South Korea, July 22, 2015. “Comfort women” is the Japanese euphemism for women who were forced into prostitution and sexually abused at Japanese military brothels before and during World War Two. (Photo by Kim Kyung-Hoon/Reuters)

In this photo taken Tuesday, June 23, 2015, a Ukrainian serviceman from the Kiev-2 volunteer battalion fires an weapon at a frontline in the village of Krymske, east Ukraine. Few places along the front line in east Ukraine see regular fighting as bitter as the village of Krymske. For now, Krymske is in the hands of Ukrainian government forces and the volunteer battalions that fight alongside them. (Photo by Evgeniy Maloletka/AP Photo)

“Igor Sikorsky (May 25, 1889 – October 26, 1972), born Igor Ivanovich Sikorsky was a Russian American pioneer of aviation in both helicopters and fixed-wing aircraft. He designed and flew the world's first multi-engine fixed-wing aircraft, the Russky Vityaz in 1913, and the first airliner, Ilya Muromets, in 1914. After immigrating to the United States in 1919, Sikorsky founded the Sikorsky Aircraft Corporation in 1923, and developed the first of Pan American Airways' ocean-conquering flying boats in the 1930s. In 1939 Sikorsky designed and flew the Vought-Sikorsky VS-300, the first viable American helicopter, which pioneered the rotor configuration used by most helicopters today. Sikorsky would modify the design into the Sikorsky R-4, which became the world's first mass-produced helicopter in 1942”. – Wikipedia

Photo: Westland Sikorsky H-5's, used by British European Airways Helicopters, which fly between London and Birmingham. The Sikorsky H-5, (aka R-5, S-51, HO3S-1, or Horse) (R-5 until 1948; company designation VS-327) is a helicopter built by Sikorsky Aircraft Corporation, formerly used by the United States Air Force, and its predecessor, the United States Army Air Forces, as well as the United States Navy and United States Coast Guard (with the designations HO2S and HO3S). (Photo by Harrison /Topical Press Agency/Getty Images). 22nd May 1951

Indonesian residents look at the Mount Sinabung volcano as it spews volcanic ash near the Tiga Pancur village in Karo, North Sumatra on August 3, 2016. Volcanic eruptions in Indonesia in recent days have forced the closure of two airports and disrupted some flights to the holiday island of Bali, officials said August 3. Mount Sinabung, a volcano on the western island of Sumatra which has been rumbling for some time, also erupted violently on August 2, although its ash clouds did not disrupt any flights. (Photo by Y.T. Haryono/AFP Photo)

In this March 7, 1991 file photo, a U.S. Marine patrol walks across the charred oil landscape near a burning well during perimeter security patrol near Kuwait City. Twenty five years after the first U.S. Marines swept across the border into Kuwait in the 1991 Gulf War, American forces find themselves battling the extremist Islamic State group, born out of al-Qaida, in the splintered territories of Iraq and Syria. The Arab allies that joined the 1991 coalition are fighting their own conflicts both at home and abroad, as Iran vies for greater regional power following a nuclear deal with world powers. (Photo by John Gaps III/AP Photo)