A U.S. Air Force F-35 Lightning II reportedly transmitted the emergency squawk code “7700” on May 10 while flying over the Sea of Oman near the Strait of Hormuz, according to reports citing Iranian state media and flight-tracking imagery. The 7700 code is the standard international signal for a general in-flight emergency, but it does not by itself reveal the cause, which can range from a technical fault to a medical issue or other urgent problem.