Have there been any successful tip-jet helicopters?

I'm not aware of any tip-jet helicopters that have made it into
production.
Please correct me if I'm wrong.

At first the idea seems a no-brainer, no torque to counter, no
gearbox, should result in a lighter & thus more efficient aircraft.
I suppose the devil is in the details.
Is the problem with tip-jets the rotor hub?
Either you have to pass fuel or hot gas through the rotor hub to the
blades.
I guess sealing a rotating assembly with hot gases flowing through may
be a non-trivial problem?
But that shouldnt be a problem for jets-at-the-tips type designs, fuel
would not be hot enough to damage seals.
Perhaps there is a inherant flaw in the jets-at-the-tips style design?

I've seen videos of the Hughes heavy lift helicopter that directed the
output of a couple of turbojets(/fans ?) through the blades.
I thought that design was successful, it was more a matter of funding
that it wasnt put into production, am I wrong?

Jeremy Thomson

On 23 Jul 2003 20:40:11 -0700, (Jeremy Thomson)
wrote:

I'm not aware of any tip-jet helicopters that have made it into
production.
Please correct me if I'm wrong.

Didn't go into production, but an interesting read nonetheless
http://www.asra.org.au/rotordyn.htm

Some other stuff I found via Google
http://www.calpoly.edu/~wpatters/helo.html
and
http://avia.russian.ee/vertigo/hiller_crane-r.html
and
http://avia.russian.ee/vertigo/hiller_hj-1-r.html
and
http://www.germanvtol.com/wnffolder/sidewnf.html

I know a guy that is building one of these
http://www.rqriley.com/gluharef.html


Phil
--
Pfft...english! Who needs that? I'm never going to England.
Homer J. Simpson

I can't say it was successful in terms of production, but I did see it fly.

Go to: http://www.intora-firebird.com/main.htm

Scooter

"Jeremy Thomson" wrote in message
m...
I'm not aware of any tip-jet helicopters that have made it into
production.
Please correct me if I'm wrong.

At first the idea seems a no-brainer, no torque to counter, no
gearbox, should result in a lighter & thus more efficient aircraft.
I suppose the devil is in the details.
Is the problem with tip-jets the rotor hub?
Either you have to pass fuel or hot gas through the rotor hub to the
blades.
I guess sealing a rotating assembly with hot gases flowing through may
be a non-trivial problem?
But that shouldnt be a problem for jets-at-the-tips type designs, fuel
would not be hot enough to damage seals.
Perhaps there is a inherant flaw in the jets-at-the-tips style design?

I've seen videos of the Hughes heavy lift helicopter that directed the
output of a couple of turbojets(/fans ?) through the blades.
I thought that design was successful, it was more a matter of funding
that it wasnt put into production, am I wrong?

Jeremy Thomson

There have been at least 2 tip-jet type helicopters to reach type
certification and production.

Sud Ouest So.1221 Djinn, about 150 produced.
http://avia.russian.ee/vertigo/snias_jinn-r.html

Kolibri H-3, about 10 produced.
http://avia.russian.ee/vertigo/nhi_kolibri-r.html


(Jeremy Thomson) wrote in message om...
I'm not aware of any tip-jet helicopters that have made it into
production.
Please correct me if I'm wrong.

At first the idea seems a no-brainer, no torque to counter, no
gearbox, should result in a lighter & thus more efficient aircraft.
I suppose the devil is in the details.
Is the problem with tip-jets the rotor hub?
Either you have to pass fuel or hot gas through the rotor hub to the
blades.
I guess sealing a rotating assembly with hot gases flowing through may
be a non-trivial problem?
But that shouldnt be a problem for jets-at-the-tips type designs, fuel
would not be hot enough to damage seals.
Perhaps there is a inherant flaw in the jets-at-the-tips style design?

I've seen videos of the Hughes heavy lift helicopter that directed the
output of a couple of turbojets(/fans ?) through the blades.
I thought that design was successful, it was more a matter of funding
that it wasnt put into production, am I wrong?

Jeremy Thomson

Brantly Nuts wrote:

There have been at least 2 tip-jet type helicopters to reach type
certification and production.

Sud Ouest So.1221 Djinn, about 150 produced.
http://avia.russian.ee/vertigo/snias_jinn-r.html

Kolibri H-3, about 10 produced.
http://avia.russian.ee/vertigo/nhi_kolibri-r.html

It says version #1 "was written off through ground resonance". Maybe due to
something like a fuel imbalance through the blades, because 2-blade rotors don't
suffer from ground resonance. Do they?

(Jeremy Thomson) wrote in message om...
I'm not aware of any tip-jet helicopters that have made it into
production.
Please correct me if I'm wrong.

The french had one in the 60's called a Djin. I saw one flying in
South Africa where they were trying to adapt it for agricultural
flying in the Cape Province. It was never very popular nor successful.

At first the idea seems a no-brainer, no torque to counter, no
gearbox, should result in a lighter & thus more efficient aircraft.
I suppose the devil is in the details.
Is the problem with tip-jets the rotor hub?
Either you have to pass fuel or hot gas through the rotor hub to the
blades.
I guess sealing a rotating assembly with hot gases flowing through may
be a non-trivial problem?
But that shouldnt be a problem for jets-at-the-tips type designs, fuel
would not be hot enough to damage seals.
Perhaps there is a inherant flaw in the jets-at-the-tips style design?

I've seen videos of the Hughes heavy lift helicopter that directed the
output of a couple of turbojets(/fans ?) through the blades.
I thought that design was successful, it was more a matter of funding
that it wasnt put into production, am I wrong?

Jeremy Thomson

"Rocky" wrote in message
om...
(Jeremy Thomson) wrote in message
om...
I'm not aware of any tip-jet helicopters that have made it into
production.
Please correct me if I'm wrong.

The french had one in the 60's called a Djin. I saw one flying in
South Africa where they were trying to adapt it for agricultural
flying in the Cape Province. It was never very popular nor successful.

The Djiin was a very successful crop spraying aircraft in the UK and France.
During the sixties and early seventies a group of them from the company
SEPATOM (I think) started the year working their way up from the south of
France spraying vines with Bordeaux mixture. Then they came to the UK and
sprayed the potatoes in Lincolnshire and Lancashire with Maneb.
About '72 BEAS Helicopters, Oxford, bought eight of them and used them for a
good few years before they switched to Bell 47s. They were cheap to run and
easy to fly but eventually shortage of spares grounded them.
Starting them was great fun, if you were fit. They had a great big handle
out the side to wind up the turbine! No electric start you see, in fact no
electric's!

Slatts

Jeremy Thomson wrote:
I'm not aware of any tip-jet helicopters that have made it into
production.
Please correct me if I'm wrong.





Where does the Hiller YH-32 fit in then?

http://www.museumofflight.org/collec...lay.html?ID=59

http://avia.russian.ee/vertigo/hiller_hoe-1-r.html


rm

(Jeremy Thomson) wrote in message om...
I'm not aware of any tip-jet helicopters that have made it into
production.
Please correct me if I'm wrong.

At first the idea seems a no-brainer, no torque to counter, no
gearbox, should result in a lighter & thus more efficient aircraft.
I suppose the devil is in the details.
Is the problem with tip-jets the rotor hub?
Either you have to pass fuel or hot gas through the rotor hub to the
blades.
I guess sealing a rotating assembly with hot gases flowing through may
be a non-trivial problem?
But that shouldnt be a problem for jets-at-the-tips type designs, fuel
would not be hot enough to damage seals.
Perhaps there is a inherant flaw in the jets-at-the-tips style design?

I've seen videos of the Hughes heavy lift helicopter that directed the
output of a couple of turbojets(/fans ?) through the blades.
I thought that design was successful, it was more a matter of funding
that it wasnt put into production, am I wrong?

Jeremy Thomson

I think that the general concensus is that they all proved extremely
noisy and consumed an inordinate quantity of fuel, 2 factors that have
limited their success and further development.

Ken J. - Sandie A. Geaux

Ken's right - tip jet designs seem like a great idea - no transmission,
minimal antitorque (you still have a small amount of friction torque and you
have to have some form of yaw control) - but tip jet drive is incredibly
inefficient. I researched these a number of years ago, as a young engineer.
I remember a quote about the YH-32, to the effect that its major success was
it's ability to turn fuel into noise.

Dan Hollenbaugh

Ken Sandyeggo wrote in message
. ..

I think that the general concensus is that they all proved extremely
noisy and consumed an inordinate quantity of fuel, 2 factors that have
limited their success and further development.

Ken J. - Sandie A. Geaux