US military plane declares sudden 'mid-flight emergency' over UK

US military plane declares sudden 'mid-flight emergency' over UK A United States Hercules military plane has been tracked heading westwards across the Atlantic before it suddenly turned around after apparently declaring an emergency and returned to Cardiff A US military plane has turned around after appearing to declare an emergency and returned to Cardiff Airport. The USAF C-130H Hercules was tracked heading westwards across the Atlantic before it suddenly turned around for unknown reasons and landed at 1.15pm. It is understood that the plane transmitted a 7700 code, indicating there is a general emergency, but at this stage it is unclear the reason. The Lockheed C-130 Hercules is a four-engine turboprop military transport plane made in the United States by Lockheed Martin. Designed to carry troops, cargo and casualties for medical evacuation, the aircraft is able to take off and land on rough unprepared runways. When a pilot enters the four-digit emergency code 7700 into their transponder, it immediately alerts air traffic control that the aircraft is in distress and requires priority handling. The exact nature of the incident is unclear as it acts as a "catch-all" for any emergency situation that isn't a hijacking (7500) or radio failure (7600). It comes after a US military aircraft declared an emergency while flying from Israel to a British airbase. The Boeing KC-135 Stratotanker, which departed Ben Gurion Airport on March 29 bound for RAF Mildenhall in Suffolk, is believed to have experienced a hydraulic issue, according to an aircraft-tracking account on X. The crew transmitted a Squawk 7700 code off the coast of Norfolk, where flight data indicate the tanker performed several loops. The aircraft appears to have been burning off excess fuel prior to landing. The crew reportedly requested a diversion to London Heathrow Airport because of its longer runway, before the aircraft landed safely at Mildenhall. Cardiff Airport is a regular stopover hub for the United States military due to several operational advantages. It has a refuelling contract with the US department of defence, it has a long runway which is capable of handling heavy military transporters and it is a relatively quiet airport.