Secondary school graduates play in a fountain as they celebrate the last day of school, traditionally called the “last bell” in central Kiev, Ukraine on May 31, 2019. (Photo by Valentyn Ogirenko/Reuters)

Firefighters and emergency personnel climb the stairs during the Melbourne Firefighter Stair Climb at the Crown Metropol Melbourne in Melbourne, Australia, 10 September 2022. The Melbourne Firefighter Stair Climb features firefighters and emergency personnel climbing 28 flights of stairs wearing 25kgs of turnout gear to raise money for mental health. (Photo by Con Chronis/EPA/EFE)

A man stands next to a barricade blocking a road during a protest calling on the government to help ease the economic effects of an harmful algal bloom that had affected their livelihoods at Chiloe island in Chile, May 6, 2016. (Photo by Pablo Sanhueza/Reuters)

Students of Kiev's Olympic College perform during a rally in front of the Parliament building in Kiev, Ukraine, 15 September 2020. Students were protesting against the reorganization of the college, at risk of being closed, and the land where it rises which could end up for sale along with the facility's stadium. (Photo by Sergey Dolzhenko/EPA/EFE)

Pedestrians are falling after a gust of wind in Munich southern Germany, Tuesday, March 31, 2015. One of the strongest storm fronts in years hit Germany on Tuesday, as Storm “Niklas” uncovered roofs, toppled scaffolding and caused severe disruption to rail services. (Photo by Sven Hoppe/AP Photo/DPA)

“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

A cat disrupts between Mexico's Tigres UANL and Real Salt Lake during a quarterfinals match as part of the Leagues Cup 2019 at Rio Tinto Stadium on July 24, 2019 in Sandy, Utah. (Photo by Jeff Swinger/USA TODAY Sports)

A worker walks through a salt pan on the eve of May Day or Labour Day on the outskirts of the southern Indian city of Chennai April 30, 2014. India is the third largest salt producing country in the world after China and U.S. with global annual production about 230 million tonnes, according to government data. (Photo by Reuters/Babu)