Key Point: The X-4 Bantam’s most valuable contribution to American aviation was to prove that semi-tailless aircraft designs were not ideal.

The X-4 Bantam had an odd tail. Rather than using traditional horizontal stabilizers, it had only the single vertical stabilizer. In the late 1940s, when the X-4 was being thought up, aerospace engineers were having difficulty getting airframes past the transonic speed range, which is up to and past the Mach 0.9 to Mach 1 range. Northrop thought they had a solution.

One of the proposed solutions was to eliminate the horizontal tail stabilizer all together, as it was believed the plane’s sharply swept wings would have been able to provide the necessary control surfaces for maneuverability in the air.

This type of design had been tried before, with limited success. The British-designed de Havilland DH 108 Swallow had a very similar design. Both the Swallow and the X-4 Bantam drew heavily on the Messerschmitt Me 163 Komet built by Nazi Germany near the end of World War II, though the Komet was a rocket, rather than jet-powered.

The X-4 was incredibly small. It had sufficient space for just the pilot, two compact jet engines, and amazingly only had a sufficient amount of onboard fuel for 45 minutes of flight time. The Bantam was designed to split open through the fuselage’s center to make servicing the little jet easier.

Despite the ease with which servicing was done, the first X-4 was considered so unreliable, that one of the Bantam project leaders called the plane a lemon. The second X-4, built to replace the first X-4 was more satisfactory. Its predecessor would never fly again and was instead was used to supply spare parts to the second X-4.

Unfortunately for the X-4 program, the semi-tailless design that was supposed to solve transonic stability issues was a rather poor solution. Near Mach 0.88, the X-4 became quite unstable, with an unpredictable pitch tendency that was compared to “driving on a washboard road.”

In addition, the Bantam was slightly unstable on all three flight axis, pitch, roll, and yaw with a preference for moving slightly along all three of these axises. The unstable little plane’s unfortunate flight characteristics couldn’t be improved, dooming the project. It would never fly after 1953.

Conclusion

By far the X-4 Bantam’s most valuable contribution to American aviation was to prove that semi-tailless aircraft designs were not ideal—indeed not feasible—in the transonic speed range with the 1950s-era technology. It wasn’t until the 1970s and 1980s that semi- or completely tailless designs were again looked at thanks to modern fly-by-wire flight control systems that rely on computer assistance to remain stable during flight.

Caleb Larson is a Defense Writer with The National Interest. He holds a Master of Public Policy and covers U.S. and Russian security, European defense issues, and German politics and culture. This article first appeared earlier this month and is reprinted here due to reader interest.

Image: Wikimedia Commons

Leave a Reply

Your email address will not be published. Required fields are marked *

You May Also Like

Why the U.S. Navy Never Built A Nuclear-Powered Surface Fleet

Here’s What You Need To Remember: At the end of the Cold War in the early 1990s, the advantage of nuclear-powered surface ships lessened. During American unipolarity, there was not a clear reason for having expensive nuclear-powered surface ships when oil would…

Could the U.S. Navy Defeat China? Russia Thinks So.

Key Point: Sivkov’s scenario is hopeful for Americans, but based on a lot of assumptions. If U.S. and Chinese aircraft carriers were to clash, the U.S. Navy would win. And who makes that prediction? A Russian military expert. Konstantin Sivkov, a…

The U.S. Navy’s “UFO” Encounters: What Do We Know?

Key point: What they saw was likely a drone or weapons test. Either way, part of the program is still declassified.  By now you’ve probably read the New York Times article a few years back detailing a UFO research program run by…

We Now Have Details On The USS Jimmy Carter Spy Submarine’s Secret Mission

Key point: We could easily have to wait another decade or more for there to be any real confirmation… On Jan. 20, 2013, the Seawolf-class attack submarine USS Jimmy Carter left her home port in Bangor, Washington. Less than two…