Back Doman LZ-1A
1950

Doman LZ-1A

In 1945, Glidden S. Doman formed Doman Helicopters Inc. in order to develop various helicopter engineering concepts. These included a new hub system which was essentially similar to the mechanism used on a variable pitch propeller. The rotor system also incorporated a gimbal mounting to provide the necessary tilting of the rotor disc. Doman's theories were tested initially by installing an experimental system on a USAF Sikorsky R-6. This helicopter was known as the Doman LZ-1A and it started flight tests in early 1950 with remarkably good results. It was followed by the larger LZ-2A Pelican.

R.Simpson "Airlife's Helicopter and Rotorcraft", 1998

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Doman Helicopters Inc. was founded in 1945 for the purpose of exploiting patents taken out by an engineer named Gliden S. Doman, who during World War II had worked with Sikorsky. The patents in question related to a new system for controlling and attaching heli-copter blades. The blades are held on the hub as if nothing more than mere variable-pitch airscrew blades. As regards the inclination of the rotor-tip plane with respect to the fuselage, this is assured by gimbal-mounting the rotor hub and rotating it by means of a unique constant-velocity driving system. No blade-flapping hinges, drag hinges or hinge dampers are required and bearings subject to centrifugal loads with oscillating motion are reduced to a minimum.

The Doman rotor incorporates the speed reduction gearing as an integral part of the rotor assembly. All moving parts are contained within a common housing which precludes damage from weather or foreign matter.

Doman first tested his rotor in 1947 on a Sikorsky R-6 which had been loaned to him by the U.S. Air Force.

Doman LZ-1A

This helicopter was a Sikorsky R-6 (lent by the USAF) converted to a Doman rotor and control system. The rotor had four blades, and though their length was increased from 11.58 to 12.2 metres, this resulted in improved hovering ability and, curiously enough, did not lower the top speed.

The first flights took place early in 1950 and it should be noted that during one experimental flight this rotorcraft flew for forty minutes without the pilot needing even once to touch the cyclic pitch control.

P.Lambermont "Helicopters and Autogyros of the World", 1958

Technical data for LZ-1A

Number of seats: 2, engine: 1 x Franklin 0-405-9 rated 245hp, rotor diameter: 12.2m, length: 10.34m, height: 3.35m, gross weight: 1350kg, empty weight: 871kg, cruising speed: 136km/h, rate of climb: 275m/min, range: 640km

Comments 
Graham Kelley, e-mail, 17.01.2017

I believe this one of a kind aircraft is restored and housed in the New England Air Museum on the north side of Bradley Field, Windsor Locks Ct.

Antonio Mariscal, e-mail, 07.12.2015

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Patrick Guisto, e-mail, 03.12.2015

I have 40 shares of stock , is of any value ? What happened to the company?

LH Levine, e-mail, 07.02.2015

I've recently came across some shares and also would like to know if the company was purchased

William Roth Jr, e-mail, 14.02.2014

My father, William Roth Sr, worked for the company in the early 1950's. As a young boy I remember taking ride in one of the helicopters as it was being tested for hovering about 6ft off the ground.

frank dacchille, e-mail, 07.04.2013

my parents recently found a few thousand stock certificates for berlin doman and would like to know their value and if the company was purchased

Dolores Corsano, e-mail, 05.07.2012

We found a stock certificate for Doman Helicopters and was wondering if anyone knew the value of this stock in today's market ?

Martie, e-mail, 15.06.2012

I only have five shares but wonder if the value of them was continued when Doman was purchased by another company?
Thank you!

Helene Scherling, e-mail, 25.04.2012

I Recently found 100shares of Berlin Doman Helicopters, and was wondering if anyone found out if these stocks are worthless now

paul, e-mail, 09.07.2011

I was giving 100 capital shares in Doman at time of birth by my grandfather. No one has been giving me answers to if they are worth anything now. I know that the company was refounded as Caribe Doman and his last intents were the D-10 and D-19. The D-10 is a variant of the LZ-5 that features a simplified,self-lubricated rotor system. eight seated helicopter first flew in 1953.the helicopter was supplied to the US Army and designated YH-31

shoes, e-mail, 11.06.2011

I've recently came across some shares and also would like to know if the company was purchased.

Judy Piccolo, e-mail, 23.11.2010

I too found stock certificates that belonged to my parents who recently passed away. Has anything been determined regarding these shares? Thanks to anyone who can give me some info.

Rich Patterson, e-mail, 19.10.2010

I also hold stocks from Doman Helicopters Inc. purchased by family in the 50's. I see that the company is no longer in business but there are many patents sold to Sikorsky Aircraft (now United Technologies) from Glidden Dorman. Don't the shareholders have any rights to these patents that were created and aquired with corporate investors money?

Rebecca Mac Lean, e-mail, 09.06.2010

I have a certificate for 100 shares purchased by my mother I am wondering if they are of any value .
Thank you

Roger Ferris, e-mail, 12.03.2010

My Dad, George Ferris, worked for Doman Helicopter in the early 1950s and perhaps in the later 40s. I remember going to the Danbury facility for an open house for employees' families and friends.

Maria C, e-mail, 16.02.2010

I also came across some stock purchased by my family. Ii would like to know whether there is any validity to the stock. Thank you for any information

John Hayes, e-mail, 02.11.2009

I am also interested if this company was acquired by another to determine if capital stock in Doman is of any value.

testpilot, e-mail, 08.09.2009

i was a demo pilot and test pilot for Doman 1954-1962 era.
Doman has bean out of business for many years.

Karen Burgess, e-mail, 04.06.2009

My father purchased some Doman Stock. Has anyone determined is Doman went out of business? Thanks

Leslie, e-mail, 13.05.2009

My family also came across some old stock certificates. Did anyone find out anything about this stock?

keith mosley, e-mail, 07.12.2008

I've recently came across some shares and also would like to know if the company was purchased

Roberta A. Violette, e-mail, 15.08.2007

My Uncle purchased Doman Stock. I am interested in finsding out if Doman was pyrchased by another company thus making the stock part of another company or if the stock is defunct.

Thanks for the help

Do you have any comments concerning this aircraft ?

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