Back Hoppicopter Strap-On

Hoppycopter Strap-On

This company was formed in December 1945 to develop the idea of an ultra-light individual helicopter conceived by Horace Pentecost, who had designed an aircraft of this type and held full rights in it.

The earliest prototype was a portable helicopter, which was attached to the flier's back by straps and harness, and which had no landing gear.

The second model on the same general lines was also fitted with a motor-cycle saddle acting as the pilot's seat, and a tubular tripod assembly with three wheels as landing gear. It was this version which was developed further. The British Ministry of Supply, incidentally, showed interest in aircraft of this kind and two Hoppicopter models were sent to the United Kingdom, for testing.

A new type of helicopter, powered by small pulse-jet engines at the blade tips, was also developed by Horace Pentecost, who had mean-while become President of the Capital Helicopter Corporation, founded in 1954, on leaving the Hoppicopter concern and retaining his rights in his inventions.

Hoppicopter "Strap-On"

This ultra-light individual helicopter had two co-axial contra-rotating two-bladed rotors powered by a small two-stroke horizon-tally opposed engine developing about 20 h.p.

The body consisted of a tubular metal frame curved to fit over the pilot's shoulders and attached to the body by harness of the type employed in parachutes; the pilot's legs were used for landing.

Some twenty hops were made with the use of safety cables attached to the pilot, but this strap-on helicopter ended its career at the Smithsonian Institution in Washington.


Technical data for Hoppicopter Strap-On

Engine: 20hp, rotor diameter: 3.66m, weight fully loaded: 90kg

manuel rosa, e-mail, 28.07.2013reply

Its funny how Horace was building the coaxial rotor way back then and sikorsky is just now catching up with Horace by buildint the X2 and saying this is going to be the Helicopter of the future.

Judith Ferguson, e-mail, 28.12.2021 manuel rosa

Horace Pentecost was my father.


Judith Ferguson, e-mail, 28.12.2021 manuel rosa

Horace Pentecost was my father.


gilbert, e-mail, 13.08.2010reply

Several years ago I started a Yahoo group for back-pack helicopters (still active at yahoo UK&Ireland)in the hope to get a working design like the Hoppicopter.
For decades (30+ years !!) I'm trying to find usefull info on the Pentacost Hoppicopter but up to now nothing has turned up.Some people claim to have the original plans or exclusive info but they all vanish when asking for something concrete.
I think a back-pack helicopter is feasable nowadays and perhaps the Hoppicopter can serve as a base for a new design.

Mr. Weiss,don't count on ANY gov. when it comes to give credit to those who deserve it !!
Your uncle surely isn't the only one who's been forgatten after partriotic service.
I surely would like to see a picture of your uncle's machine but I understand that you obviously won't be eager to do this.

Kindest regards

william, e-mail, 11.11.2010reply

where could i find a strap on hoppicopter?that is in good working order would love to try it out and fly around where i live at is there anyway you could help me out of finding one thank you hope to hear from you soon take good care

Brad, e-mail, 09.05.2011reply

Wow, this is very similar to The Explorer back pack gyro copter we developed a few years ago. We are currently preforming flight tests. Our ready to fly unit only weighs 121 lbs with 5 gallons of fuel. google Bradley Aircraft for more information.

Dominique SAVARIAU, e-mail, 10.06.2011reply

I have the original "sciences et vie" french magazine 1945 that describes the hoppicopter; It is as well as you guys my dreamsince 35years to build one and since then I collectinformation and watch carefully technics improvements ; I do think, now a days, that time and technology are ready for a safe back pack machine.... Nevertheless there are a lot of political and security issues in that invention; Gvts do not want to loose control!; On one side freedom and equivalent amount of control on the other side.... not sure as well it would be cost effective; Anyway I like it and still work on it;

Marc de Piolenc, e-mail, 13.05.2014reply

The earliest successful helicopter - the Bréguet - was coaxial, and the Kamov design bureau in Russia actually put several coaxials into production, but there are significant engineering problems and drawbacks with them - particularly clearance between the two sets of blades. Rigid rotor systems and composite blades have finally made them come into their own, as in the Sikorsky X-2.

santhanu krishnan, e-mail, 02.03.2012reply

i have the same idea of building the same type,but my challenge is to find an engine which can produce 40bhp and weight 40kilos. i am still searching for basic designs are ok , i need a sponser ,is thatany one ready to help me? contact me in my mobile 8695128511.

Sam Carr Polk, Esq., e-mail, 29.11.2013reply

My friend Lomis Slaughter, Jr. worked at Boeing during WWII. He told me that at a company party during the War one of the aeronautical engineers who was a cartoonist drew a cartoon of another who was a helicopter freak - as a mosquito, hanging under rotors with an engine on his back! But the latter took it seriously, and invented the Hoppicopter and sold it to the Army. Could that have been Horace Pentecost?

Judith Ferguson, e-mail, 28.12.2021 Sam Carr Polk, Esq.

I love this story. Horace Pentecost was my father.


peter Weiss, e-mail, 19.04.2010reply

In the mid 1930's my uncle built and used a similar strap on flying machine for survey work in China before the outbreak of WW2. He used a main rotor for lift along with a torque stabilizing rotor. The main rotor was perpendicular to his back and he positioned himself for lift like a runner leaving a starting gait and balanced the weight like a "fireman's carry". The machine is made of aluminum and cast iron and weighed 72 1 /2 pounds when fueled. We are in possession of this machine, the original plans, photographs and films of it's operation and all the engineering specs. We are currently seeking patent infringement awards. We are not seeking publicity and choose to remain as anonymous as possible . It bothers my family that my uncle, HM Weiss, received no acknowledgement from our government for his patriotic sacrifices and his remarkable engineering skills.

MIchael J., e-mail, 30.03.2010reply

I was given access to the unit at Pima. It's weight is 110 Lbs. I am building a modern update of the unit based around the basic control system. It's been a 7 year hunt for info but it was worth it. Contact me for more info.

Michael J. XI Aviation

William May, e-mail, 15.01.2010reply

The Hoppicopter doesn't weigh 200 lbs. That is the weight with a soldier AND the Hoppicopter. That is, the unit is designed to operate at a weight of 200 lbs. total. I have looked at the unit that is in the Pima Air Museum, and I estimate it probably weighs about 30-40 lbs. max. It is really tiny when you see it up close, and is mostly made of aluminum. I think the cylinder was cast iron, but aside from the steel gears and fittings, and rotor mast, everything else appeared to be aluminum castings.

Vitaliy, e-mail, 21.02.2009reply

I think, i have more intresting constraction of Hoppicopter.

GUY, e-mail, 26.10.2007reply

The thing weighs 200lbs. How the heck does the opperator put this thing on. What is missing from thses pictures?

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