A Boeing KC-135 Stratotanker, a key US Air Force aerial refuelling aircraft often called a “flying gas station,” triggered concern after issuing a “7700” transponder code—signalling a general in-flight emergency—while flying over the Persian Gulf near Iranian airspace, according to Flightradar24 data.
The aircraft reportedly took off from Al Dhafra Air Base in the United Arab Emirates and was operating in support of ongoing US military activity in the Middle East before the emergency signal was detected.
Tracking data showed the plane flying in a circular pattern before beginning its descent, with its signal getting lost over Qatar. The exact cause of the emergency remains unclear.
There has been no official statement from the US military so far, and there is no indication at this stage of hostile action or external interference.
Iranian media outlet Fars News Agency also reported the incident, citing public flight tracking data, but did not attribute responsibility.
Emergency signal over sensitive airspace
The KC-135’s 7700 squawk code typically indicates an onboard emergency ranging from technical failure to medical or operational issues.
🔴 یک فروند هواپیمای سوخترسان KC-135R نیروی هوایی ایالات متحده آمریکا که از پایگاه هوایی الظفره امارات برخاسته بود، در حین پرواز بر فراز خلیج فارس، کد اضطراری ۷۷۰۰ را مخابره کرد.
— خبرگزاری فارس (@FarsNews_Agency) May 5, 2026
🔹ارسال این کد به معنای وجود یک وضعیت اضطراری و فوری است که نیاز به فرود دارد. pic.twitter.com/o3HBB660hs
The aircraft’s route over a sensitive region has drawn attention given ongoing geopolitical tensions involving Iran and US forces in the area.
What does the KC-135 do?
The KC-135 Stratotanker is a long-serving US Air Force refuelling aircraft that enables fighter jets, bombers, and reconnaissance planes to remain airborne for extended missions.
It can also transport cargo and personnel and is used in medical evacuation operations, making it a critical support asset in US military operations worldwide.