Iran has fitted one of its old, American-made RH-53D helicopters—nose number “704”—with an inflight-refueling probe, allowing the heavy, long-range copter to extend its flying distance even farther by drawing gas from an airborne tanker.

The retrofit—apparent in recent state media photos—is the latest evidence of Tehran’s desperate yet resourceful efforts to maintain and even improve its bizarre, geriatric aerial arsenal, which is largely composed of pre-Islamic Revolution U.S. hardware from the 1970s plus Russian gear that Iran seized from Iraq.

But the addition of a refueling probe also raises a fascinating question. For at the moment, Iran has not admitted to possessing a tanker plane that can fly slow enough to refuel the RH-53D. Does the appearance of a probe-equipped helicopter indicate that Tehran is working on a new fleet of aerial tankers? […]