Dubai: A Boeing KC-135 Stratotanker triggered a “7700” distress signal — the universal code for an in-flight emergency — while flying over the Arabian Gulf, before its transponder signal disappeared, according to flight-tracking data.

What is the KC-135 Stratotanker?

The US KC-135 Stratotanker, which acts as a flying gas Station for US military planes, is a military aircraft powered by four turbofan engines mounted under swept wings and used mainly for aerial refuelling.

The aircraft has a cargo deck above the refuelling system, allowing it to carry both passengers and equipment, and is used to transfer fuel to other aircraft mid-air.

It has been part of US Air Force operations for more than 60 years and plays a central role in extending the range and endurance of fighter jets, bombers and surveillance aircraft.…