Two weeks into the war involving Iran, the United States has lost another aircraft. The crash has pushed the total number of American aircraft losses in the conflict to four.

On Thursday (March 12), the United States Central Command announced that a military refuelling aircraft, the KC-135 Stratotanker, crashed in western Iraq during an ongoing operation against Iran.

The US military said the incident was not caused by enemy fire or friendly fire. However, an Iran-backed Iraqi militant group has claimed responsibility for shooting down the aircraft.

What Is the KC-135 Stratotanker?

The KC-135 Stratotanker is a long-serving aerial refuelling aircraft developed by Boeing during the 1950s and early 1960s.

For decades, it has been one of the most important aircraft in the US military’s refuelling fleet. The aircraft allows fighter jets and bombers to stay in the air longer by refuelling them mid-flight. This capability helps aircraft complete long-distance missions without needing to land.

According to available data, the US Air Force operated 376 KC-135 aircraft in 2025. Of these, 151 were on active duty, 163 served with the Air National Guard, and 62 were part of the Air Force Reserve.

The aircraft is also used to support multiple branches of the US military. It provides aerial refuelling for the US Air Force, Navy, Marine Corps, and aircraft belonging to allied nations.

Besides refuelling missions, the aircraft can transport cargo. Depending on fuel capacity, it can carry as much as 83,000 pounds of cargo. The KC-135 can also be used for aeromedical evacuations, transporting injured patients who are able to move with assistance. In 1998, the aircraft cost about $39.6 million, according to the US Navy. Adjusted for inflation today, that amount is roughly $79.6 million.

Details of the Crash

The crash occurred on Thursday (March 12) when an American KC-135 participating in Operation Epic Fury against Iran went down in western Iraq. The last recorded crash of a KC-135 happened in 2013. In that incident, the aircraft was on a refuelling mission over Afghanistan and crashed shortly after taking off from Manas airport in Kyrgyzstan.

In the latest incident, the US military said the crash was not caused by hostile or friendly fire. “The incident occurred in friendly airspace during Operation Epic Fury, and rescue efforts are ongoing,” the Central Command said in a statement. Officials added that another aircraft involved in the mission — also a KC-135 — landed safely without any problems.

The military also said further information would be released as the investigation continues. According to the statement, authorities asked for patience while details are collected “to provide clarity for the families of service members.”

Militant Group Claims Responsibility

Despite the US military’s claim that the crash was not caused by an attack, an Iraqi militant alliance linked to Iran has said it was responsible. The group, known as the Islamic Resistance in Iraq, said it had shot down the aircraft.

In a statement, the group said it targeted the plane “in defence of our country’s sovereignty and airspace”. The claim has not been independently confirmed.

Rising Tensions With Iran

The crash happened as tensions continued to escalate between Washington and Tehran. Iran’s security chief, Ali Larijani, recently warned that Iran would make the United States “sorry” for launching the war against the country.

The conflict began on February 28 after US-Israel strikes targeted Iranian sites.

Crew and Possible Casualties

It is still unclear whether anyone was killed or injured in the crash. A US official told the Associated Press that five people were on board the aircraft at the time.

Normally, a KC-135 operates with a three-member crew consisting of a pilot, co-pilot, and boom operator. However, additional personnel may sometimes be present during missions.

US Aircraft Losses in the Iran War

The KC-135 crash marks the fourth US aircraft lost since the war began on February 28. Earlier in the conflict, three F-15E Strike Eagle aircraft were accidentally shot down in a friendly fire incident by air defences in Kuwait.

All crew members from those fighter jets managed to eject safely and survived.

US Troop Casualties So Far

Apart from aircraft losses, the United States has also suffered troop casualties. So far, seven American service members have died in the conflict. The Pentagon also reported that around 140 troops have been injured, including eight who are in serious condition.

Six of the deaths occurred when an Iranian drone struck an operations centre at a civilian port in Kuwait. The soldiers were members of the Army Reserve and were responsible for logistics operations that supplied troops with food and equipment. The seventh soldier died after being wounded in an attack on Prince Sultan Air Base on March 1.

Earlier, US President Donald Trump and Defence Secretary Pete Hegseth warned that more American casualties could occur before the war ends.