XH-26 Jet Jeep

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The XH-26 Jet Jeep (known as the XA-8 by its manufacturer) was an experimental helicopter developed in 1951 by the American Helicopter Division of the Fairchild Engine and Airplane Corporation to meet a U.S. Army and USAF request for a collapsible and air-droppable observation helicopter.

Design and development

The design of the original Model XA-8 single-seat lightweight helicopter began in 1951 under the sponsorship of the U.S. Army Transportation Corps and the USAF. The Army's specification in 1950 had called for a light-weight, one-man unarmed helicopter that had to be collapsible, capable of aerial delivery to troops in rugged terrain, and assembled quickly with simple tools. The helicopter was to be used for both light observation and as an air-droppable rescue vehicle for downed aircrew. After a review of all proposals American Helicopter was awarded the development contract in June 1951, based on its XA-8 design proposal. The first of five prototype XH-26s flew in January 1952.

The XH-26 was constructed of aluminum, except for the aft fuselage which was laminated fiberglass, and possessed a well-glazed, pyramidal-shaped cockpit. When collapsed, its five foot by five foot by fourteen foot container fit on a trailer which could be towed by a military Jeep. If stripped for air drop the Jet Jeep weighed less than 300 pounds, and it could be assembled by two men in just 20 minutes. The XH-26 did not use any gears, or an internal engine like other helicopters. Rather, the Jet Jeep was powered by two 6.75-inch pulsejets mounted on the end of each rotor blade tip as tipjets. Designed by American Helicopter, each pulsejet weighed just 16 pounds yet produced 35 pounds of thrust, and were started with an internal compressed air system. Since the engines did not have to be warmed up, the XH-26 could take off in just 30 seconds. The pulsejets produced no torque, and the tiny, belt-driven tail rotor was used only to improve directional control.

American Helicopter chose the name "Jet Jeep" because the XH-26 could be used like a Jeep, but in the air. It could be transported by a Jeep, and even used the same fuel.

Both the Army and USAF evaluated the five prototype Jet Jeeps. They proved to be rugged and durable vehicles with a top speed of 80 mph and a ceiling of 7,000 feet. Unfortunately, the pulsejets produced an unacceptable amount of noise and the Army found the aircraft unsuitable. Finally, cost considerations forced the cancellation of the program. The replacement of the pulsjets with ramjets was suggested but never undertaken.

urvivors

*XH-26 s/n 50-1840 is on display at the United States Army Aviation Museum located in Ozark, Alabama
*XH-26 s/n 50-1841 has just completed an extensive restoration and is on display in the Modern Flight Gallery at National Museum of the United States Air Force in Dayton, Ohio

Operators

;USA
* United States Air Force
* United States Army

pecifications (XH-26)

aerospecs
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met or eng?= eng

crew=1
capacity=
length m=3.73
length ft=12
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rot number= 1
rot dia m= 8.23
rot dia ft= 27
rot dia in= 0
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height m=1.88
height ft=6
height in=2
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volume m3=
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aspect ratio=
empty weight kg=135
empty weight lb=298
gross weight kg=320
gross weight lb=705
lift kg=
lift lb=

eng1 number=2
eng1 type=American Helicopter XPJ49-AH-3 pulsjet
eng1 kw=
eng1 hp=
eng1 kn= 0.2
eng1 lbf= 35
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max speed kmh=135
max speed mph=84
max speed mach=
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range km=
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endurance h=
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ceiling m=2134
ceiling ft=7000
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ee also

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similar aircraft=
* Hiller YH-32 Hornet
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References

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