A man stands at a passenger train damaged in a collision with a freight train in Moscow region May 20, 2014. The passenger train on its way to Moldova collided with a freight train near Moscow on Tuesday, killing at least four people and injuring 15, a spokeswoman for Russia's Emergencies Ministry said. The reason for the collision, near the town of Naro-Fominsk 55 km (34 miles) southwest of Moscow, was not immediately clear. (Photo by Grigory Dukor/Reuters)

Passengers from a passing train watch as rescue workers search a train which crashed in Karachi, Pakistan, November 3, 2016. At least 17 people have been killed and dozens more injured after two trains carrying hundreds of passengers collided in Pakistan's southern port city of Karachi, officials said. (Photo by Akhtar Soomro/Reuters)

Laura Halford of Wales jumps during her hoop routine as she competes in the rhythmic gymnastics individual all-around final event at the 2014 Commonwealth Games in Glasgow, Scotland, July 25, 2014. (Photo by Phil Noble/Reuters)

“The McDonnell Douglas KC-10 Extender is an air-to-air tanker aircraft in service with the United States Air Force derived from the civilian DC-10-30 airliner. The KC-10 was the second consecutive McDonnell Douglas transport aircraft to be selected by the US Air Force following the C-9 Nightingale. The similar KDC-10 is in service with the Royal Netherlands Air Force.”

Photo: A B-52G Stratofortress aircraft takes off with another B-52G close behind. Three cells of six B-52 and KC-10 Extender aircraft will takeoff seconds apart under combat conditions during the minimum interval takeoff exercise. The exercise is a part of an operational readiness inspection by the Strategic Air Command Inspector General Team. (Photo by USAF). 1998

“With the traditional tapping-ritual, the Oktoberfest has been opened on saturday, September 22, 2012. Despite the rather wet weather on saturday, the first weekend was te xpeted sucess: Approximately 850.000 guests from Munich, Bavaria, the rest of Germany and from all over the world came to visit the 179th Oktoberfest on the opening weekend. About one million liters of beer and about nine oxen have already been sold”. – Oktoberfest.de. (Photo by ◊CHЄЄKY◊MINX◊PHOTO◊DIARY◊)

North Koreans wave as Hughes MD-500 helicopters fly past during an aerial display on Saturday, September 24, 2016, in Wonsan, North Korea. North Korea on Saturday opened an air festival featuring sky diving, demonstrations by its air force and lots of beer to promote a newly renovated and upgraded commercial airport in the coastal city of Wonsan that it hopes will draw for foreign tourists. (Photo by Wong Maye-E/AP Photo)

A Boeing F/A-18 takes off to perform during the Farnborough International Airshow in Farnborough, Britain, 12 July 2016. The Farnborough International Air Show runs from 11-17 July. (Photo by Hannah Mckay/EPA)

A F-16 fighter jet from The Thai Royal Air Force performs during a media demonstration at the Korat Royal Thai Air Force Base, Nakhon Ratchasima province, Thailand, November 24, 2015. Thailand's military held an air show with China on Tuesday ahead of joint manoeuvres in a sign of warming ties, but Thailand said it was not distancing itself from the United States which downgraded the military relationship following a 2014 coup. (Photo by Athit Perawongmetha/Reuters)