The design of the Model XA-8 single-seat lightweight helicopter was undertaken in 1951 with the sponsorship of both the Army Transportation Corps and the USAF. The Army specification to which American Helicopter had responded in 1950 had called for a light, collapsible machine which could be used as both a light observation craft and as an air-droppable rescue vehicle for downed aircrew. American Helicopter was awarded a development contract in June 1951, and the first of an eventual five XH-26s flew for the first time almost exactly one year later.
The XH-26 was designed from the beginning to be both collapsible and air-droppable and its construction and diminutive size reflected both requirements. Only twelve feet long and just six feet tall, the helicopter could be transported in a five foot by five foot by fourteen foot container and could be unpacked and assembled by two men in less than thirty minutes. The machine's fuselage was built primarily of aluminum and fiberglas and featured an extensively glazed, pyramid-shaped cockpit. The XH-26 was powered by two pulse-jet engines, one fixed to the tip of each main rotor blade, and could burn virtually any type of fuel.
The Army and Air Force jointly evaluated the five XH-26 prototypes from 1952 to 1954. The machines were found to be robust in construction and relatively simple to operate, but neither service procured the type in quantity.
S.Harding "U.S.Army Aircraft since 1947", 1990
American Helicopter H-26
|<!font size=3>Technical data for American Helicopter H-26
engine: 2 x American Helicopter XPJ49-AH-3 pulse-jets, rated at 16.2kg,
main rotor diameter: 8.23m,
fuselage length: 3.73m,
take-off weight: 320kg,
empty weight: 135kg,
max speed: 130km/h,
cruising speed: 110km/h,
service ceiling: 2280m,
|Mpeirwe David, e-mail, 01.02.2017||reply|
technology is a good thing. I would love to own this small helicopter for personal use if it was in my means.
|Gerald L. Wiles, e-mail, 14.07.2016||reply|
Whoops! I goofed. My earlier answer to Marc de Poinlenc was mixed up, being more about Aeromarine's Navy smokescreen generator than the pj for AHC.
The "Siamese" pj we made for AHC was a single power plant but utilized 2 separated tailpipes and one blended com-bustion chamber; there was no gate valve in the system. The c-cs were about 6 in. diameter but were joined into a figure "8", making them about 12 in. wide. The exhaust pipes were about 3.5 in. dia. and 15 in. long. A single, 11 in. wide X 3.5 in. high bank of reeds was incorporated, vaguely similar to those in the Argus pj that powered WWII's V-1. However, our reeds were I piece, ea., and were left flat rather than being curved as in the V-1.
|Gerald L. Wiles, e-mail, 14.07.2016||reply|
To Marc de Piolenc, I'm answering your question after a delay of 3 years! Sorry.
Aeromarine's pj for American Helicopter was composed of 2 blended sections. Its combustion chambers and tailpipes were separate. A gate valve was placed between the c. chambers,just downstream of the reed valves,and their exhaust outlets were merged into a single, larger discharge. With the gate being closed, one of the sections was started normally then the gate was opened. hot gasses from the operating section then blasted into the idle section, inducing air and fuel to flow into it. The heat ignited the fresh charge, starting a flow through the second tailpipe. Almost instantly, the 2 sections became synchronized and they continued operating as a single pj.
|Marc de Piolenc, e-mail, 21.08.2013||reply|
This is a question for Gerald Wiles: what do you mean by "Siamese" pulsejet? Could you elaborate or perhaps give a link?
|Gerald L. Wiles, e-mail, 23.05.2013||reply|
In 1951-52, Aeromarine Co. (originators of the Dyna-Jet,) created a Siamese p-j for powering the AHC XA-6. I helped in its being tested and shipped to AHC. They enclosed it in a dedicated housing that improved performance but we were never credited.
|Thomas, e-mail, 15.11.2011||reply|
What I'd like to know, is what counteracted the torque of the rotor? I dont see anything on the tail. Would the pilot just hold the rudder slightly faced in a certain direction?
|Mike, e-mail, 26.03.2012||reply|
My comment is in response to the question that Thomas made. I'm not sure of you'd received an answer yet but there is no torque to counter act against as yhe locomotion to drive the rotor is generated at the blade tips and not through a conventional gearbox mounted to tge air frame. The rudder / air foil in the rear allows the aircraft to yaw from both the down wash of the rotor and the force of the air moving around the aircraft while in forward flight (relative wind). Well, I hope that my two cents worth makes at least a little sense to you. I've always loved these weird type of flying contraptions too. Best Regards
|Romain, e-mail, 29.05.2009||reply|
Hi, does anybody have some details about this project. I would be very happy to know more about this. If you can provide information, please contact me.
|kiran, e-mail, 20.04.2009||reply|
will u send me model sketch of your project let me know something about your project please
|emmy samuel, e-mail, 03.05.2007||reply|
i must say it is the world most tiniest invention, for personal and hobby use. it a good work keep it up, cheer the world tiniest vtol ever built.
|Dr. Layth.A.W.Ayoub, e-mail, 12.02.2007||reply|
Nice ultralight project,easy to built,easy to drive ,easy to transfer,with no moving parts engine, but with high noise.I encourage developing it for personal local use with changing pulse jet to ramjet so its pulsed noise may be reduced when it becomes continious. Thank you for this picture.I like to keep contact with you .I remain
Do you have any comments ?
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