In what may initially seem counterintuitive, the US military has supported the development of a helicopter that does not have an engine. One can even visit the army Aviation Museum in Fort Rucker in Alabama to see this design by an American Helicopter Company called the Jet Jeep.
The Jet Jeep was considered for many decades as a light surveillance solution needed by the military. The U.S. military was looking for a light surveillance flight, and that meant enough to carry one or two people at most. That’s pretty much the problem manufacturers of jet backpacks trying to solve these days. But that was back in the 1950s, and helicopters and planes were largely the way flying worked.
So the US Air Force took on this task and made a lighter version of the helicopter, the XH-26, by skipping the larger engine. Instead, he placed two pulsed jets AJ7.5-1 at the end of each of his rotors and also managed to avoid the transmission system, which further reduced its weight, according to the U.S. military’s website.
The prototype resulting from this experiment weighed less than 300 pounds (136 kg), was foldable and could be placed in a storage container that could then be towed by a jeep. They just needed two people to put it back together, and that could be done in less than 20 minutes, according to Website of the National Museum of the United States Air Force.
Reactive impulses also offered an added advantage. One can miss tail rotor system which is used in helicopters to provide anti-torque capability. However, when the military began testing the prototype, design flaws came to the fore. The reactive impulses were extremely strong and gave the position of the location of the plane at night.
If one of the impulse jets breaks down, the plane will simply crash and this is where another big problem has been revealed. Due to its small footprint, the XH-26’s fuel tank was located just below the pilot’s seat and in no way protected the pilot from serious injury.
Although the likelihood of surveillance with the plane is not in question, the military reportedly tested the plane for two people a few years later. He built a total of five prototypes to test the concept over and over again, but eventually postponed the project and Jet Jeeps became part of the Army and Air Force Museums.