The US Department of Defense (DoD) says its fighter aircraft shot down an unidentified high-altitude object off the northern coast of Alaska.

The incident occurred on 10 February around 13:45 Eastern Standard Time. A two-ship flight of Lockheed Martin F-22 stealth fighters were dispatched by US Northern Command (NORTHCOM) from Elmendorf AFB in Anchorage, Alaska.

F-22s over Alaska

Source: US Air Force

US Air Force F-22 stealth fighters from Elmendorf AFB, Alaska responded to the airspace incursion near Prudhoe Bay

One of the F-22s dispatched the unknown object with a single Raytheon AIM-9X Sidewinder air-to-air missile at an altitude of roughly 40,000ft. The Pentagon says the operation was carried out at the order of US President Joe Biden.

“At this point we don’t know the origin of the object,” says DoD press secretary Brigadier General Pat Ryder.

The Pentagon says it is not yet able to determine what the object was, although Ryder adds there is no indication it was a crewed aircraft. The order to shoot it down was based on an assessment from NORTHCOM that the object posed a potential hazard to commercial aviation.

Ryder says the joint USA-Canada North American Aerospace Defense Command (NORAD) had been tracking the object since 9 February. The downed object is reported to have crashed on sea ice near Prudhoe Bay, Alaska.

The Pentagon says it has multiple aircraft in the area responding, including a Lockheed HC-130 search and rescue transport, Sikorsky HH-60 combat search and rescue helicopter, and a Boeing CH-47 Chinook heavy lift helicopter.

The Federal Aviation Administration (FAA) issued a hazard alert over its Notice to Air Missions (NOTAM) system on 10 February for the airspace around Deadhorse, Alaska, which is now closed.

“The [FAA] classifies the airspace defined in this NOTAM as [national] defence airspace”, the message reads. The agency adds deadly force may be used against any aircraft in the area not complying with airspace restrictions.

Data from flight tracking service FlightRadar24 shows a single HC-130J Combat King repeatedly circling an area some 31nm (55km) off shore from Prudhoe Bay around the time the Pentagon says the unknown object was downed.

“We have no further details about the object at this time including any description of its capabilities, purpose or origin,” says Ryder.

The latest incident comes one week after a large balloon craft belonging to China passed over the USA, including Alaska, without permission from Washington. The Pentagon claims it was a surveillance platform and shot down the airship off the coast of South Carolina.

Alaska C130 flight path

Source: Screenshot from FlightRadar24

A US HC-130J circled an area off Prudhoe Bay, Alaska for several hours following the downing of an unidentified object in the area

Defence officials and the Biden Administration have received bi-partisan criticism in Congress for allowing that balloon to overfly US airspace, including sensitive military sites, for several days.

The DoD maintains the balloon in that case did not pose a physical or intelligence threat, and the USA stands to benefit from being able to recover the dirigible’s surveillance package from the shallower waters off South Carolina.

Ryder on 10 February said the DoD cannot yet confirm whether or not the object shot down in Alaska was also a balloon-type aircraft, but notes there are some initially obvious differences from the previous craft.

“The [Alaska] object was about the size of a small car, so not similar in size or shape to the high altitude surveillance balloon that was taken down off the coast of South Carolina,” he notes.

NORTHCOM says the balloon shot down near South Carolina was approximately 60m (200ft) tall with a payload the size of an Embraer ERJ regional jet.

When questioned if political criticism led to a more immediate use of force in the 10 February incident, Ryder says the deciding factor was the hazard the unknown object posed to commercial aviation.

“We’re going to judge each of these objects on its own merits,” he notes. “We sent up aircraft to assess what it was and the decision was made that it posed a reasonable threat to civilian air traffic.”

By contrast, the surveillance balloon maintained an altitude above the ceiling for commercial air traffic during its transit of North America, the DoD says. It was between 60,000ft and 65,000ft when NORTHCOM ultimately brought it down with an air-to-air missile.

The incidents represent the first-ever combat kills for the F-22 air superiority platform, which despite being designed in the 1990s remains one of the most formidable fighter aircraft in the world.