A demonstrator throw a firebomb during clashes with Turkish riot police officers in Istanbul, Turkey, Friday, May 1, 2015. The government assigned 30,000 police officers backed by helicopters as workers and demonstrators determined to defy a government ban, tried to march to iconic Taksim Square, where 35 people were killed during May Day celebration in 1977. (Photo by Emrah Gurel/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

A Pakistani child, whose family was displaced by 2010 floods from a village in Pakistan's Sindh province, sits on a wooden cart outside her family's makeshift home, in a slum on the outskirts of Islamabad, on February 8, 2013. (Photo by Muhammed Muheisen/AP Photo)

Lowry Park Zoo elephants Matjeka, 23, and her 1-year-old daughter, Mavi, apply a liberal coating of “sunscreen” to themselves in a clay mud wallow at the park Tuesday, August 12, 2014, in Tampa, Fla., on the park's first observation of World Elephant Day to raise awareness of the wild African elephant crisis. “Elephants are prone to being sunburned”, said associate curator Chris Massaro. “What they need is lot of mud or clay to roll around in and cover up their skin so it will protect it from the sun”. (Photo by Cherie Diez/AP Photo/The Tampa Bay Times)

Breath of an Arctic fox by Marco Gaiotti, Italy. Marco was watching this little Arctic fox as it incessantly called another nearby. Gradually he noticed the fox’s wet breath was quickly freezing in the air after each call. It was late winter in Spitsbergen, Svalbard, and the air was -35C (-31F). Photographing Arctic foxes is often frustrating, as they are normally running around fast in search of food, but this one was very relaxed and let Marco get close enough to focus on it, with the light glowing perfectly in the background. (Photo by Marco Gaiotti/Wildlife Photographer of the Year 2021)

Russians play accordions as they walk near the building of the Federal Security Service (FSB, Soviet KGB successor) in Lubyanskaya Square to mark May Day in Moscow, Russia, Sunday, May 1, 2016. As in Soviet times, about one hundred thousand of cheerful workers paraded across Red Square despite a chilly rain, but instead of red flags with the Communist hammer and sickle, they waved the blue flags of the dominant Kremlin party and the Russian tricolor. (Photo by Alexander Zemlianichenko/AP Photo)

A Ukrainian serviceman fires a 2S7 Pion self-propelled gun during military exercises near the village of Divychky in Kiev region, Ukraine, October 21, 2016. (Photo by Valentyn Ogirenko/Reuters)

A woman jumps on a giant fried egg art installation as part of “Hecho en Casa” (Made at home) urban artwork festival in downtown Santiago, Chile, November 8, 2016. (Photo by Pablo Sanhueza/Reuters)