Željava Air Base, situated on the border between Croatia and Bosnia and Herzegovina under Plješevica Mountain, near the city of Bihać, Bosnia, was the largest underground airport and military air base in the former Yugoslavia, and one of the largest in Europe. (Photo by Thomas Windisch/Exclusivepix Media)

A passenger plane, with a full Harvest moon seen behind, makes its final landing approach towards Heathrow Airport in London, Britain, October 5, 2017. (Photo by Toby Melville/Reuters)

Saudi female firearm trainer, Mona Al Khurais, teaches a Saudi boy on safe usage of weapons at the Top-Gun shooting range in Riyadh, Saudi Arabia, October 28, 2021. (Photo by Ahmed Yosri/Reuters)

Armed Syrian Turkmen villagers are seen near the northern Syrian village of Yamadi, near the Turkish-Syrian border, Syria, November 24, 2015. Turkey shot down a Russian warplane near the Syrian border on Tuesday saying it had repeatedly violated its air space, one of the most serious publicly acknowledged clashes between a NATO member country and Russia for half a century. (Photo by Reuters/Stringer)

Udomsak Ratanotayo, left, and Suttinan Boonsomkiat wear storm trooper costumes while donating blood at the Thai Red Cross in Bangkok, Thailand on Monday, April 28, 2014. Thai Star Wars fans will donate blood and give toys at an orphanage as part of a promotional campaign. (Photo by Sakchai Lalit/AP Photo)

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

People look at a tanker after it fell into a caved-in area on a road in Xi'an, Shaanxi province, July 27, 2013. No casualty was reported in the accident, according to local media. (Photo by Reuters/Stringer)

A handout image provided by the New Zealand Defence Force shows aid supplies being unloaded by Fijian soldiers from an Royal New Zealand Airforce C-130 Hercules plane in Suva, Fiji, 23 February 2016. Tool kits, generators, ration packs, water containers and chainsaws make up part of the New Zealand relief following Tropical Cyclone Winston. The death toll from the cyclone that hit Fiji over the weekend climbed to 29, local media reported ON 23 February. Cyclone Winston, the most powerful storm in Fiji's history, battered the country's main island of Viti Levu and other smaller surrounding islands on Saturday, the Fiji Broadcasting Corporation reported. (Photo by Sam Shepherd/EPA/NZ Defence Force)