On Oct. 19, 2001, 200 U.S. Army Rangers parachuted onto a dry lake bed near Kandahar, Afghanistan. After securing the drop zone and finding...

On Oct. 19, 2001, 200 U.S. Army Rangers parachuted onto a dry lake bed near Kandahar, Afghanistan. After securing the drop zone and finding a nearby Taliban compound empty, the elite soldiers boarded a number of U.S. Air Force MC-130H Combat Talon II transports and left the battlefield.

Even if Taliban forces had been nearby, they lacked radars to spot the incoming raiders or large numbers of deadly surface-to-air missiles that might’ve scuttled the American mission before it even started. Even so, the Pentagon sent stealthy B-2 bombers to hit nearby targets before the Rangers touched down.

Against a more high-tech enemy, the specialized troop-carriers and their human cargo might’ve been much more vulnerable.

By 2009, the Air Force’s commando headquarters had started looking at acquiring a stealthy transport plane to make infiltrating hostile areas a safer proposition. Dubbed “Project IX,” the proposed plane would have filled multiple “gaps and shortfalls” in existing aircraft such as the Combat Talon, according to the Air Force.

“Project IX will provide significantly better aircraft performance,” Air Force officials write in a concept document that War Is Boring obtained via the Freedom of Information Act. “The … configuration has yet to be determined and additional analysis will be required.”

Above — an MC-130H Combat Talon II. At top — Air Force commandos jump from an MC-130H. Air Force photos

While the flying branch didn’t have a specific design in mind, it did have very clear requirements for what would be a brand-new plane. The aircraft’s primary missions would be sneaking commandos into defended territory, bringing them supplies if necessary and then getting them out safely — just like the MC-130H does.

Crews would be able to do so regardless of the time of day, the temperature or the weather. The plane would even function under chemical, biological or nuclear attack.

Most importantly, the new plane would take advantage of “low-observable” technology — in other words, it would be stealthy. A radar-evading shape would be central to the design. Like the Air Force’s upcoming B-21 bomber, the project would require the utmost secrecy.

“There are lessons learned and precedents for such responsibility regarding other specialized aircraft (F-117, B-2, F-22, etc.),” the report explains. “Project IX will take full advantage of them.”

A graphic in the report features nondescript black silhouettes to depict the Project IX planes in their larger context. No other art is present in the declassified portions of the document.

The need to hide from hostile radar has become critical, as countries including Russia and China keep cooking up new, longer-range surface-to-air missiles to go along with the sensors. Potential enemies such as Iran and North Korea are equally keen to upgrade their air defenses.

Moscow claims its new S-500 missiles will be able to hit targets nearly 400 miles away at speeds exceeding 2,000 miles per hour. By the end of 2016, Tehran is hoping to finally take delivery of older, but still dangerous, S-300 missiles.

Besides being able to slip past these defenses, the stealthy transport would be able to fly at least 1,000 miles on a single tank of gas — a very conservative requirement. The Combat Talon can go more than twice this distance.

The report explains that the original goal was a 2,000-mile round trip, plus an additional 15 minutes of fuel to cover multiple passes over the target area. Mid-air refueling would help extend the plane’s range.

The new design needed to take off and land in 1,500 feet or less. A standard C-130H requires more than twice that distance to get airborne with a full load of cargo and fuel.

The new commando transport would have to be just as good on impromptu dirt airstrips as it was on well-maintained, concrete runways. Of more than 10,000 airfields around the world in a 2007 National Geospatial Intelligence Agency database, fewer than 1,500 were paved, according to the document.

Not surprisingly, the aircraft would get top-of-the-line communications equipment, powerful radars and video cameras and other special gear. The proposed crew of three — pilot, co-pilot and loadmaster — might grow in order to fly spy missions.

However, despite the stealthy design, the Air Force conceded that a Project IX plane might not be able to pass undetected into heavily defended zones every time. So, on top of its special shape, the plane would boast a suite of electronic countermeasures to spot and jam enemy radars and radios.

“Regardless of altitude and the … technologies incorporated into Project IX, visual and electronic detection of the aircraft may still be possible,” the document notes. “Vulnerabilities to threats are expected.” As with the older MC-130H, crews could still use terrain-following radar to fly as low as 200 feet off the ground in certain situations.

We don’t know how far the Air Force got with the stealth transport. Four years later, the flying branch took a look at, but never pursued, radical upgrades to the MC-130H as part of a follow-on program called Project 10.

The service planned to get the first of the Project IX aircraft sometime between 2019 and 2010. But we have yet to see the plane out in public. It might exist. It might not.