PDA

View Full Version : Hiller XH-44 Hiller-copter


okikuma
07-31-2013, 06:38 PM
This is the only film I could find concerning the Hiller XH-44 Hiller-copter being flown inside the University of California Berkeley Stadium back in 1944. I'm sure there's a longer version of this film with sound.

I'm discovering there's not much public information in detail about the transmission and rotor system.

Juergen, you're very good in searching obscure information. Let's see what you can add to this thread.

Thanks,

Wayne

"Helicopters in the News" - YouTube (http://www.youtube.com/watch?v=lE8RJM-Stto)

WaspAir
07-31-2013, 07:54 PM
Have you asked the folks at the Hiller Aviation Museum in San Carlos, CA? They may information to share (they had the original on loan from the Smithsonian for a long time, did some reverse engineering, and were soliciting funds for building a replica).

okikuma
07-31-2013, 09:02 PM
Hi J.R.,

No I haven't contacted the Hiller Museum. I have yet to visit the museum there, however that is on my bucket list for this year.

I've always been interested and impressed with the XH-44 ridged rotor design. It was a very advanced design in it's day. The claim of the rotor blades being an all metal design I think is a misnomer. In some photos, I can clearly see fabric covering on the blades.

I think I'm also safe to assume that the XH-44 never was flown fast enough into translational lift since I can not find any information listing top speed or cruising speeds. I also bet that most of the 1,244 lb empty weight is in the transmission and rotor system.

I wonder how well the XH-44 design would fly in cruise flight if it was updated by adding an extended aluminum tube boom with an "H" style empennage just outside the rotor disk area?

Wayne

Atic
07-31-2013, 11:15 PM
Hi J.R.,

No I haven't contacted the Hiller Museum. I have yet to visit the museum there, however that is on my bucket list for this year.

I've always been interested and impressed with the XH-44 ridged rotor design. It was a very advanced design in it's day. The claim of the rotor blades being an all metal design I think is a misnomer. In some photos, I can clearly see fabric covering on the blades.

I think I'm also safe to assume that the XH-44 never was flown fast enough into translational lift since I can not find any information listing top speed or cruising speeds. I also bet that most of the 1,244 lb empty weight is in the transmission and rotor system.

I wonder how well the XH-44 design would fly in cruise flight if it was updated by adding an extended aluminum tube boom with an "H" style empennage just outside the rotor disk area?

Wayne

In the first picture: is it my old eyes or does that upper rotor has a different airfoil than the lower one ?
Top one seems to be symetric,lower one asymetric.

I guess the blades have been build old style with ribs like an airplane wing in those days.

Remarkable man, mr. Stanley Hiller, also one of the very few who was lucky enough to be able to spend money on his dreams as a youngster.

It is said that Larry Bell was fond of "the Kid".

Arnie Madsen
08-01-2013, 05:30 AM
Jay Spenser has an excellent book for under $20
Vertical Challenge:
The Hiller Aircraft Story
by Jay Spenser

another good one is
Whirlybirds
A History of the U.S. Helicopter Pioneers
by Jay Spenser

About $70 and worth every penny.
Has great sections on ... Stanley Hiller ... Frank Piasecki ... Arthur Young ... Igor Sikorsky


Spenser is one of the best aviation authors
http://www.jayspenser.com/my_other_books.html

Rotor Rooter
08-01-2013, 06:23 PM
I'm discovering there's not much public information in detail about the transmission and rotor system.

Here is some more information on the Hiller XH-44 (rigid, 2-blades/rotor) (http://www.aviastar.org/helicopters_eng/hiller_xh-44.php)
and on the Hiller X-2-235 (rigid, 2-blades/rotor) (http://www.aviastar.org/helicopters_eng/hiller_x-2-235.php)

Apparently they were the first coaxial helicopters with 'absolutely ridge rotors', which is the basis of Sikorsky's Advancing Blade Concept.
The use of only two blades per rotor causes an extremely large 2/rev vibration when the cyclic stick is moved off center.


Dave

okikuma
08-04-2013, 04:38 PM
Hi Gilbert,

I agree with you that in the first color photo, the nearest lower blade airfoil with the red tip does appear to be asymmetrical, however it is an illusion. Look at the root of the opposite lower blade and one can view that the airfoil is symmetrical like the rest.

Hi Dave, you mentioned the large 2/rev vibration that is experienced with a rigid two blade rotor system. When reviewing the video, one can notice some vibration with the main landing gear at the wheels.

Hi Arnie, I will have to check out the two books you recommend by Jay Spencer. Thanks for the information.

Wayne

Atic
08-06-2013, 12:00 AM
Hi Gilbert,

I agree with you that in the first color photo, the nearest lower blade airfoil with the red tip does appear to be asymmetrical, however it is an illusion. Look at the root of the opposite lower blade and one can view that the airfoil is symmetrical like the rest.

Hi Dave, you mentioned the large 2/rev vibration that is experienced with a rigid two blade rotor system. When reviewing the video, one can notice some vibration with the main landing gear at the wheels.

Hi Arnie, I will have to check out the two books you recommend by Jay Spencer. Thanks for the information.

Wayne

You're right Wayne, thanks.
What the hell is "good" about getting old LOL !!!

Must have been a golden era ! Founder of the company could say: that's what I have in mind, that's what we gonna build, period !!
If it's a mistake, my failure. If it's a succes, my pride.
No fancy over payed management teams just the vision of one man, prepared to take the risk of being laughed at.

GA Rotor Guy
08-06-2013, 05:44 AM
You're right Wayne, thanks.
What the hell is "good" about getting old LOL !!!

Must have been a golden era ! Founder of the company could say: that's what I have in mind, that's what we gonna build, period !!
If it's a mistake, my failure. If it's a succes, my pride.
No fancy over payed management teams just the vision of one man, prepared to take the risk of being laughed at.

Seems to me: In a sense... us Gyro 'barnstormers' are living that era with our 'mad max' aircraft... :D

Thankfully (to a degree) we live in a country where we are still free enough to do this... Many a place that would not be allowed.

Atic
08-06-2013, 10:12 PM
Hail to you sir for realising the freedom you Americans still have !!
Don't give that freedom away for political correct BS.

I love the Mad Max style gyro's !!!

GA Rotor Guy
08-07-2013, 05:36 AM
Hail to you sir for realising the freedom you Americans still have !!
Don't give that freedom away for political correct BS.

I love the Mad Max style gyro's !!!

Yeah... yet it dwindles as each new polecat (politician) takes a thin slice away. I think in my lifetime I will remain free... I wonder about the grandkids though. However this is not meant to be a political discussion... I am respectful of not turning a fun flying forum into fussing about govt types.

If there were a 'fussing' section at RWF, we could go there and solve the world's problems... :cool: