Twinstarr?

[-willy-]

I saw some Twinstarr gyros on the Facebook page of the Mentone gathering. I am curious about them and would like more info if possible.

The tail looks fascinating. Can anyone give me details of this bird?
I am attaching a pic from a Google search so the rest of you know what I am talking about. I can only find sideviews.

 

[barnstorm2]

Twinstarr Gyroplanes:

Produced by Farrington Aircraft (KY USA) as a kit.

Almost thirty kits were rumored to have been produced, over twenty flying machines have been documented.

Two have been damaged beyond repair, both suffered unskilled landings (unlicensed pilot/low time pilot), no serious injuries.

Although no formal information has been found, the generally accepted motivation for the design was to build a low-thrust line (near CLT) trainer that was durable and highly reliable.

It is also believed that the Twinstarr was in the FAA certification process but this was not completed due to the death of the company owner (not Twinstarr related).

Frame: Chrome-molly steel with rigid mast
Blades: Stock 30ft RAF (many have been upgraded to Sport Copter 30's)
Engine: Lycoming 0-320 150 or 160hp
Fuel: 15 gallons
Range: Approximately 1 hour 45 minutes at cruse with reserve.
Speed: 30-100mph 103mph VNE (RAF BLADES)

Note: Some people that do not understand thrust-line calculation assume that the Twinstarr is low-thrust-line because it does not have the 'step ladder' look of many CLT machines. This is not correct.

Unlike Rotax engines that have a redrive that raises the thrust-line above the engine, the Lycoming engines have no redive, they use a direct dive system which makes the ENGINE exact CLT.

Airframe Design:

Most designers tried to solve the high thrust-line problem by raising up the pilot and passengers and dropping the keel.

The Twinstarr takes the approach of REMOVING THE KEEL and dropping the engine down to line up the thrust-line with the bellybuttons of the pilot and passengers.

With no keel the large horizontal stabs are placed in front of the prop rather than behind the prop.

Production:

The Farrington Aircraft tooling for the Twinstarr was purchased by a man from Europe, and believed to be damaged in a fire.

The buyer also claimed to have purchased the "rights" however this has since been myth-busted, no rights were ever transferred and are now believed to be in the public domain.

Gary Goldsberry is one of the top experts on the Twintstarrs. Gary owns the prototype Twinstarr #1 and has been training in it for a decade. He has also completed several Twinstarr kits and restored several used Twinstarrs.

.

 

[Capt'n Gator]

Twinstarr

Twinstarr

I believe Brent Brown has one

 

[-willy-]

Anyone know of any plans that might be available?

 

[bopflyer]

Thanks for sharing the information on this gyro. I have always liked the look of the Twinstarr and would love to build one with a lighter engine some day.

Cheers

Barry

 

[barnstorm2]

Anyone know of any plans that might be available?

All of the drawings and manuals are available in the PRA online archives.

.

 

[Brent Drake]

Thanks for sharing the information on this gyro. I have always liked the look of the Twinstarr and would love to build one with a lighter engine some day.

Cheers

Barry

Barry, I would not put a light weight engine on it. there really isn't any. It was designed for a Lycoming which is an average weight engine.

Remember the Lycoming it does not take a radiator or a gear box and is basically center line thrust.

 

[barnstorm2]

Barry, I would not put a light weight engine on it. there really isn't any. It was designed for a Lycoming which is an average weight engine.

Remember the Lycoming it does not take a radiator or a gear box and is basically center line thrust.

I agree.

The Twinstarr was designed to use the lycoming.

All attempts to use Soob and Mazda engines on the TS have failed miserably. They made weak machines with bad thrustlines.

.

 

[-willy-]

So what were the outcomes of using a Yamaha or Rotax?

 

[-willy-]

All of the drawings and manuals are available in the PRA online archives.

.

Only available to members of the PRA. Not available to public download.
Can you post the link?

 

[Stan V]

Only available to members of the PRA. Not available to public download.Willy

Freedom is not free, someone has to pay. Please consider joining PRA, we need your support, Thank you. Stan V.

 

[barnstorm2]

Only available to members of the PRA. Not available to public download.
Can you post the link?

No.

The PRA has over 11,000 files in the archives FREE, OPEN FOR EVERYONE.

This is part of the 'public service' that the PRA provides to promote and support the sport of personal rotorcraft.

The link is in the signature of all of my posts on this forum.

Freedom is not free, someone has to pay. Please consider joining PRA, we need your support, Thank you. Stan V.

Thank you Stan!

You are correct. Although the public archives are free to the public the PRA does pay to have the content hosted on a server and it takes time to keep the files sorted, scanned and available.

Please join or donate.

Your memberships strengthen our sport.

.

 

[Brent_Brown]

I know that woody flew his twinstarr with a 80 HP engine. I see no reason why you can't put a 914 on it and fly. from the info I have a empty TS is in the 750 pound range with the Lycoming. you can save 100 pounds or more and if you turbo a 912 you can get 120 or what ever they are getting now on the 912 turbos on a ZEN gyro. You might have to move the head forward put not a show stopper.

 

[bopflyer]

What does the Lycoming weigh?
Problem is that at 750 ponds range it leaves little margin for the max weight limit for gyros in NZ

 

[-willy-]

Yes I hear you about joining. Yet $42 is about what we have for a week of food.

Sucks to be financially challenged.

 

[Brent Drake]

The Rotax an Yamaha Are both marginal engines for the Twinstar although they would work.

My Twinstar weighs 700# with a Lycoming 0320 160hp. Will carry a 320lb guy with very high density altitude. Few few machines will carry that kind of passenger wit ha 225lb pilot.

Lycoming 0320 160hp weight is 268lbs.

A rotax 912s is about 140 lbs plus radiator and coolant. 100hp

Lycoming has dual ignition systems for reliability.

I can't see spinning a motor at 5,000rpm then gearing it down to 2800rpm. A lot of wasted wear and tear on everything

So for about an extra 100lbs of weight. You get double the reliability, and an extra 60hp.

 

[Brent Drake]

I can't see why Rotax can't change the cam and such to reduce RPM's.

 

[WHY]

a much lighter engine (say a katech if they are successful) is going to make a major change in CG.

Tony

 

[Capt'n Gator]

PRA membership

PRA membership

Yes I hear you about joining. Yet $42 is about what we have for a week of food.

Sucks to be financially challenged.

Willy, I know what you mean about being financially challenged, been there, times are better now ( Thank God ).

Let me offer to pay your first year's membership, It would be my pleasure to bring you into the fold of gyro nuts and you sound like someone with the right enthusiasm. If you find that you don't like the PRA, than you would not have to renew, give it a shot. I am serious about my offer!!!!

Capt'n Gator:usa:

 

[TJMay]

Willy, I know what you mean about being financially challenged, been there, times are better now ( Thank God ).

Let me offer to pay your first year's membership, It would be my pleasure to bring you into the fold of gyro nuts and you sound like someone with the right enthusiasm. If you find that you don't like the PRA, than you would not have to renew, give it a shot. I am serious about my offer!!!!

Capt'n Gator:usa:

A very gracious offer!

And for a good reason.

Tommy