stuart fields

I'm quite curious about this groups response to an announcement of a new
magazine about experimental helicopters. There has been essentially no
response. I'm sure surprised. Is there a basis for this group that I'm
unaware of that would create a total lack of curiosity or comment? I'm at
a loss to understand this.

hennie roets

Stu,
This group is not as active as what it used to be. There are also
people in this
group that think we have a death wish flying experimental rotorcraft. They
do not
think that a good helicopter can be developed without spending billions of
dollars.
I just got the idea but might be completely wrong.

Hennie

dave jackson

The bad news.

Most modes of transportation have changed relatively little during the past
70 years. For example, the automobile had, and it still has; four wheels, an
enclosed heated passenger compartment, a reciprocating engine and a steering
wheel. In addition, the speed limit has not changed, whereas the speed limit
of the computer doubles every two years. In part, this slow development is
because the transportation industry is a mature one.

This is inability to improve is particularly apparent in the field of
rotorcraft. Boeing has stated " The Chinook was developed in the late 1950s,
less than a decade after the B-52 bomber entered service. Since then, two
follow-on bombers have been fielded, but no new heavy-lift helicopter."

This lack of significant advancement in rotorcraft has resulted in a
diminishing number of people being involved in rotorcraft R & D. In
addition, this small collection of people is thinned out even further by
their diversity of interests. Jokingly, at one extreme are the few whose
'research consist of discovering whether a NC nut or a NF nut is used on a
NF bolt. At the other extreme are the few whose research consists of
modeling the blade vortex in 5D.

This reduced activity at the various levels of rotorcraft development
manifests itself in many ways. One of these is in the peripheral support
industries, such as publications. How many times can the same ideas be
regurgitated?


The good news;

I am convinced that the field of rotorcraft has fallen behind that of other
modes of transportation. There is an opportunity to catch-up, but, it will
only come about when its leaders step out of the box. This box is the
mindset that has embraced the abominable tail-rotor and excluded the more
efficient latterly-located-twin-main-rotors.

Frustrated defense departments and some industry leaders are now starting to
look in this direction. They are also looking at very-light rotorcraft, to
be used as UAVs,

There is absolute no reason why the recreational/experimental side of
rotorcraft cannot experience a developing and exciting future by moving in
the same direction.


This posting may appear to be self-serving, but there is no commercial
interest on my part.

Dave J. http://www.UniCopter.com

kathryn & stuart fields

Dave: Thanks for your response. I've begun to think that I'm talking about
enjoying bigamy to a group of Catholic priests. Your Joke about the
research of discovery of the NC nut vs. the NF bolt hit my funny bone. I
will use that somewhere in the magazine in the future.
To your hate/dislike for the tail rotor. I don't know whether you have a
helicopter or not or if you maintain one, but I'm convinced that I can't
afford a twin rotor ship. The blades for my Safari are over $5,000/ set.
The transmission, and it is much simpler than what will be required for a
twin rotor ship is around $15,000. The Rotor heads, the control linkage???
Having just finished balancing the tail rotor and main rotor blades on my
Safari, my imagination runs away with me when I start thinking about trying
to balance two main rotors at the same time with the mutual interference
possible. How do the big boys with lots of $$$ do it?? There is a two seat
tandem rotor helo being developed for the kit market in Canada. Their price
guess is over $100K. There will be few that can afford this toy. All these
high prices for a helicopter that basically is a recreation device that
can't earn it's keep. We are constantly barraged by people looking for a
more affordable, otherwise they can't join in, ship. I think that the
research we need is both into ways to drive the costs of the present
configurations down, and exploring some of the advantages displayed in
things like the Cheyenne.
My "Research" is into the cause and elimination of the 2/rev vibrations in a
two bladed helicopter. With my limited funds, my progress is very slow. I
am, however, mentally engaged in the project and being an engineer, this
keeps me out of mischief.

Stuart Fields Editor/Publisher of the Experimental Helicopter magazine.

dave jackson

Hi Stu,

Your concerns about price are understood, but for a counter argument;-

My background is in manufacturing, and more specifically, the manufacturing
of equipment that is used to mechanize and automate the production and
assembly lines of other companies. Without qualification, it can be said
that the single largest contributor to lower prices, by far, is 'economies
of scale'

Roughly speaking, the main-rotor/tail-rotor helicopter has twice as many
different types of parts as the twin-main-rotor helicopter. The
twin-main-rotor helicopter will have double the production run due to the
commonality of parts. Logic suggests that the twin-main-rotor helicopter
will cost less than the main-rotor/tail-rotor helicopter.

In addition, latterly-located-twin-main-rotors have a number of aerodynamic
advantages.

I really believe that this configuration is the future of rotorcraft, and
this future may arrive next month. The only current request for a new
helicopter in the USA is the DARPA competition for an Unmanned Combat Armed
Rotorcraft. An intermeshing helicopter and a compound helicopter are the
two finalists that are competing for the authorization to build a prototype.


There is no reason why the affeceadoes of recreational helicopters can't
start looking at the 'second coming of rotorcraft'. A little preaching in
your new magazine might lead the unconverted out of the wilderness.

Dave J.

no

I'm

I'm

kathryn & stuart fields

Boy do I understand that..I manufacture a rotor speed alarm system. It is
basically for the Safari, but easily modifiable to others. With the small
market the individual prices have to be high to cover my costs. I also
built some cyclic simulators that I thought should sell for $50. My cost
was closer to $200. If I could build 1,000... Yeah you were preaching to the choir here.

Logic does not suggest that the twin main will cost less than the main-tail
ship unless you can produce in large quantities. Logic obviously says that
the main-tail is less costly for single items. Your argument may hold
water for some yet to be determined production numbers. Just remember the
market for kit helicopters is not large. If you go into the certified
ships, you will learn, as Frank Robinson has learned, there are some
overhead costs that can jack your costs up that aren't covered in a simple
economies of scale model..


I agree here just based on what I see the Kamans doing.


prototype.
I used to have great respect for DARPA (I had an interface with them in the
70's) until they pulled off that "Great Challenge", which they called a
"Success". I had inside poop from a guy working on the set up for that
FARCE. DARPA spent $12M on the setup for that event and only pre-tested the
entrants on a flat well defined track. I think that the managers are
running DARPA now and apparently they don't understand tech issues very
well. I would be very cautious about using DARPA's seal of approval to mean anything.


Dave: I have a problem with Moller AirCar, Ezcopter, Skyscooter and a few
of the others with their "positive forward thinking" when they haven't built
and tested the item to really know what they are talking about. They claim
"Easy to build and Easy to fly" and haven't built and tested the prototype.
The Skyscooter does not have collective controls and I believe therefore
very questionable autorotation ability.. These have to be rectal
extractions since they haven't gone the whole route. I'm surprised at
people, however, a friend told me of an investment banker that tried to dump
a bunch of bucks on an untried and unflied helicopter kit a few years ago
just based on the artist's conception. As I understand it the twin rotor
machines can have pedal reversal during autorotation. That would not be
something that I wanted to expereince during an engine out emergency.
I'm coming to the conclusion that this newsgroup has a different idea or
definition of recreational helicopters. A lot of the posts that I see are
coming from people interested in big $ commercial ships. Only a very small
percentage of the posters seem to be involved in recreational rotorcraft
flying. .

Stu Fields

jim

small

jim

Stu, I will be interested in the magazine when it becomes monthly and thick
(not with ads not related to helicopterst either).

an opinion only mindya
Jim

dave jackson

Stu,


OK forget DARPA.

A couple of years ago the US Army requested concepts for a new heavy lift
helicopter. Bell proposed the quad-rotor V-44, Boeing proposed a
side-by-side configuration and Sikorsky proposed a single rotor with a
reverse velocity capability. Sikorsky's concept appears flawed [
http://www.synchrolite.com/1281.html#Potential_Problems ], which leaves
multiple main rotors as the only contenders.

OK forget what the big boys are doing ~ although it does suggest the future
of rotorcraft.

Let's consider simple low cost helicopters, similar to those that were built
in the beginning. Last year Tom Lawrence, a senior engineer at Sikorsky


derided at the time, the single-rotor configuration would come to dominate
the worlds helicopters." What an interesting statement. Those who "Much
derided" the single-rotor helicopter had good cause. They were not ignorant
people. In fact, some of the most knowledgeable rotorcraft people at that
time were in Germany. Both Flettner and Focke had built better helicopters
then Igor, before he built his. Perhaps Igor's "faith" was a sort of 'blind
faith'. Or, perhaps his faith was placed in marketing; to DARPA type
government employees.

The main/tail rotor helicopter and the twin-main-rotor helicopter have the
same total number of blades and gears etc. The former has big parts and it
has small parts. The latter has only identical medium size parts, but twice
as many. Savings from volume production starts at 2-off. This is because
the machine setup cost, the purchasing cost, etc. etc. are now 1/2 per part
for what they would be for only 1-off.

Me too, but the Intermeshing helicopter is a proven configuration.

The intermeshing helicopter does have pedal reversal during autorotation.
Offsetting this argument; the intermeshing helicopter (Flettner FL-282) was
the first helicopter to enter and exit autorotation. In addition, the US
armed services stopped using Kaman Huskie helicopters for training their
pilots because they were too easy to fly.

If someone starts building recreational twin-rotor helicopters, the people
will come.

Dave J.
"Kathryn & Stuart Fields" <sfkf@iwvisp.com> wrote in message news:ZtWdnW--Lr34osXcRVn-uA@iwvisp.com...

dump

small

stuart fields

The twin rotor helicopter does have a c.g. range advantage and for heavy
lifting (internal cargo especially) they would be hard to beat. Also how
big of a rotor can you build for a single rotor machine? Multiple blades
and you would have a parking problem..


Well not exactly. I get quantity discounts only after I purchase at least
10 things and sometimes the quantity discount doesn't start until I reach
100. Now if these items were rotor blades? Look at the production run for
Bell 206 blades and the cost of these things!!! I understand the Schweitzer
blades for the 300 are $15,000 each blade( $45,000 a set!!!!) There are
quite a few 300s out there.. I will agree that the tooling costs get
amortized over the run; but I had better have a good idea what the run is
going to be before I start....


It hasn't been proven in the price range for personal helicopter operation.
How many do you think that you would have to produce to make them cheaper
than an R-22 (which most of us can't afford)? If you are really talking
about the commercial operating machines, I might agree with you that the
intermeshing rotors might have a future. It would depend on acquisition and
maintenance costs. One of the prime reasons I play with the experimental
class ship is that I can't afford the maintenance costs of a Bell 47 D-1,
Schweitzer 300CB etc. The Parts and Labor for these machines is too much
for my budget. Especially when I can fly my bird just as fast and hover
just as high as either one of them. The maintenance costs have to be as
high or probably higher for an intermeshing rotor system.


Could be. I talked to one logging operator that had a hovering auto from
150' with little or no damage to the ship(Kaman). That is a bit high for a
Bell 47... No he didn't drop the nose and get a bunch of airspeed. He was
over the logging landing and the only place to land was directly below. I
would definitely feel safer screwing around in one of those...

You know I agree. But will enough come to make it an economically viable
operation?? We'll soon have a picture with the La Flamme ship being built
in Canada. Cute mini CH 47 (two seat). Initial target price is well over
$100k and will increase from there as reality sets in.
I'll still kiss the ring of anyone that comes up with a two seat
recreational class twin rotor helicopter kit for under $100k a copy that can
demonstrate economical viability for more than 3 years..
Stu Fields Skeptic but hopeful.

ago

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