MI-28N helicopter of aerobatic team Berkuts fly during an air show marking 75th anniversary of 6th air force army of Russia in St. Petersburg, Russia, Sunday, June 4, 2017. (Photo by Igor Russak/NurPhoto via Getty Images)
MI-28N helicopter of aerobatic team Berkuts fly during an air show marking 75th anniversary of 6th air force army of Russia in St. Petersburg, Russia, Sunday, June 4, 2017. (Photo by Igor Russak/NurPhoto via Getty Images)