A U.S. Air Force U-2 spy plane prepares to land as South Korea and the United States conduct the Max Thunder joint military exercise at the Osan U.S. Air Base in Pyeongtaek, South Korea, Wednesday, May 16, 2018. North Korea on Wednesday canceled a high-level meeting with South Korea and threatened to scrap a historic summit next month between President Donald Trump and North Korean leader Kim Jong Un over military exercises between Seoul and Washington that Pyongyang has long claimed are invasion rehearsals. (Photo by Kwon Joon-woo/Yonhap via AP Photo)





A U.S. Navy F/A-18 launches from the USS Carl Vinson in this undated handout picture released November 1, 2014. U.S.-led air strikes hit Islamic State positions around Kobani earlier in the day in an apparent effort to pave the way for the heavily-armed Kurdish contingent to enter. (Photo by US Navy/Handout via Reuters)





A Kamov Ka-52 Alligator helicopter takes part in a dynamic exposition at the International Military Technical Forum “Army 2018” in Patriot Park in Alabino, Moscow region, Russia, 21 August 2018. About 1,200 Russian defense companies and weapon manufacturers take part in the event, displaying an estimated 26,000 pieces of weaponry and military equipment, ranging from helicopters and fighter jets to tanks and small arms, the organizers said. (Photo by Sergei Ilnitsky/EPA/EFE)





Two 1 Squadron Hawker Siddeley Harrier GR1s during a field deployment exercise codenamed Snowy Owl, UK, 1972. (Photo by Air Historical Branch/RAF/PA Wire)





Damaged jet fighter of type Eurofighter is transported on the platform of a truck on German highway number nine near Plech, southern Germany, on May 28, 2015. The jet fighter has been transported to a factory in Manching, southern Germany, after beeing damaged during a collision with a civil airplane in June 2014. (Photo by Daniel Karmann/AFP Photo/DPA)





The Air Force Air Demonstration Squadron Thunderbirds Delta flies over the Golden Gate Bridge. The Thunderbirds were returning from the California Capital City Air Show to Nellis Air Force Base. (Photo by U.S. Air Force by Staff Sgt. Ashley Corkins)





A U.S. Air Force F-22 Raptor takes off from a South Korean air base in Gwangju, South Korea, Monday, December 4, 2017. The United States and South Korea have started their biggest-ever joint air force exercise with hundreds of aircrafts including two dozen stealth jets. (Photo by Yonhap via AP Photo)





A F15 is refuelled by a U.S Air Force KC-135 during a European Tanker Symposium from RAF Mildenhall, Britain May 17, 2018. (Photo by Darren Staples/Reuters)





U.S. Air Force Major Paul “Loco” Lopez performs in an F-22 Raptor during the AirPower Over Hampton Roads JBLE Air and Space Expo at Joint Base Langley-Eustis, Virginia, U.S. May 18, 2018. Picture taken May 18, 2018. (Photo by Staff Sgt. Areca T. Bell/Reuters/U.S. Air Force)





A U.S. Air Force F-16 fighter approaches a KC-135 aerial refueling aircraft during the U.S. led Saber Strike exercise in the air over Estonia June 6, 2018. (Photo by Ints Kalnins/Reuters)





German Air Force Eurofighter Typhoon takes-off during the air policing scramble in Amari air base, Estonia, March 2, 2017. (Photo by Ints Kalnins/Reuters)





Three U.S. Air Force F-15E Strike Eagles, from Mountain Home Air Force Base, Idaho, fire flares over the Utah Test and Training Range, west of Salt Lake CIty in Utah, U.S., July 3, 2018. (Photo by Airman 1st Class Codie Trimble/Reuters/U.S. Air Force)





Two Czech Gripen fighter planes demonstrate a flight interception of a Belgian air force transport plane over the Czech Republic, as part of NATO drills on September 12, 2018. (Photo by Francois Lenoir/Reuters)





An F-16 aircraft of the Turkish Stars aerobatic team of the Turkish Air Force performs during Teknofest airshow over the city's new airport under construction in Istanbul, Turkey September 20, 2018. (Photo by Osman Orsal/Reuters)





A United States Marines V-22 Osprey helicopter carrying members of the press following President Donald Trump is seen as Trump traveled from New Jersey to Manhattan in New York City, New York, U.S., September 23, 2018. (Photo by Mike Segar/Reuters)





An Airbus helicopter NH90 TTH (Tactical Transport Helicopter) of German army Bundeswehr takes part in an exercise during a media day in Bergen, Germany September 26, 2018. (Photo by Fabian Bimmer/Reuters)





In this August 22, 2017, file photo provided by the U.S. Navy, a C-2A Greyhound assigned to the Providers of Fleet Logistics Support Squadron (VRC) 30, prepares to land on the flight deck aboard the aircraft carrier USS Theodore Roosevelt (CVN 71). The U.S. Navy has located a transport aircraft deep on the Pacific Ocean floor where it crashed in November, killing three sailors on board. The C-2A Greyhound aircraft, which was traveling to the aircraft carrier USS Ronald Reagan when it crashed the day before Thanksgiving in the Philippine Sea, rests at a depth of about 18,500 feet (5,640 meters), the Japan-based 7th Fleet said in a statement Saturday, Jan. 6, 2018. (Photo by Mass Communication Specialist 3rd Class Alex Corona/U.S. Navy via AP Photo)





An F-22 departs Langley Air Force Base, Va., Tuesday morning, September 11, 2018, as Hurricane Florence approaches the Eastern Seaboard. Officials from Joint Base Langley-Eustis in Hampton said the base's F-22 Raptors and T-38 Talon training jets, as a precaution, were headed for Rickenbacker Air National Guard Base in central Ohio. (Photo by Jonathon Gruenke/The Daily Press via AP Photo)





A Sukhoi Su-35S fighter jet of the Russian Eastern Military District performs a test flight over the Ajax Bay by Russky Island in Vladivostok, Russia on September 5, 2018 ahead of the 2018 Eastern Economic Forum to be held on September 11-13, 2018. (Photo by Yuri Smityuk/TASS)





A US Air Force F-22 Raptor stealth jet flies over a South Korean air base in Gwangju on December 4, 2017 The US and South Korea on December 4 kicked off their largest ever joint air exercise, an operation North Korea has labelled an “all- out provocation”, days after Pyongyang fired its most powerful intercontinental ballistic missile. (Photo by AFP Photo/Yonhap)