Paramedics carry an injured woman out from a subway station after a rush-hour subway train derailment, to be transported by a medical helicopter in Moscow, Russia, on Tuesday, July 15, 2014. A rush-hour subway train derailed in Moscow Tuesday, killing 20 people and injuring at least 150, emergency officials said. Several cars left the track in the tunnel after a power surge triggered an alarm, which caused the train to stop abruptly. (Photo by Ivan Sekretarev/AP Photo)

Russian servicemen look on as a Mi-24 helicopter fly overhead during the Open Water competition for pontoon bridge units, as part of the International Army Games 2018, outside Murom, Russia August 3, 2018. (Photo by Maxim Shemetov/Reuters)

The Peugeot of Sebastien Loeb of France is seen turned over next to a helicopter during the eighth stage in the Dakar Rally 2016 near Belen, Argentina, January 11, 2016. (Photo by Andre Lavadinho/Reuters/World-ASO)

A helicopter from the Venezuela's Army takes part in a military parade to celebrate the 207th anniversary of Venezuela's independence in Caracas, Venezuela July 5, 2018. (Photo by Marco Bello/Reuters)

A shot of Pu'uo crater, the main source of lava from Kilauea, taken from a helicopter in Kilaura, Hawaii. (Photo by Kirk Aeder/Barcroft Media)

An activist of the anti-G8 forum “Block G8” shows his middle finger to a police helicopter passing overhead June 07, 2007 at Bollhagen, near Heiligendamm, Germany. (Photo by Carsten Koall/Getty Images)

A handout photo made available by the Indian Air Force (IAF) showing an IAF helicopters during the rescue operation in flood affected areas of Dhanyaghari of Khanakul in West Bengal, India, 02 August 2021. According to the IAF, helicopters of Indian Air Force rescued 31 people from rooftops and brought them to safety to Arambaug. The helicopters also dropped emergency food supplies in the affected areas after the torrential rain in the state has thrown life out of gear and created flood like situation in many districts. (Photo by Indian Air Force/Handout via EPA/EFE)

Russian Mi-28N from the Berkuty (Golden Eagles) helicopter display team fly in formation during the “Aviadarts” military aviation competition at the Dubrovichi range near Ryazan, Russia, August 2, 2015. The aircraft started dipping down due to back propeller failure and crashed, killing one of two pilots, according to a Reuters photographer and official representatives of the competition. The aviation contest is part of the International Army Games, which are held in Russia from the 1st till the 15th of August with participants from 17 countries, according to organizers. (Photo by Maxim Shemetov/Reuters)