Groen Bros. DARPA Award

[John A. Landry]

GROEN BROTHERS AVIATION SELECTED BY THE UNITED STATES DEPARTMENT OF DEFENSE
ADVANCED RESEARCH PROJECTS AGENCY (DARPA) TO DESIGN NEXT GENERATION ROTORCRAFT
FOR COMBAT SEARCH AND RESCUE

Salt Lake City, Utah - November 7, 2005 - Groen Brothers Aviation, Inc.

(GBA) (OTC: BB GNBA) announced today that the US Defense Advanced Research
Projects Agency (DARPA) has selected a GBA-led team to design a proof of
concept high speed, long range, vertical takeoff and landing (VTOL) aircraft
designed for use in Combat Search and Rescue roles. Phase one of this
potentially multi-year $40 million four phase program, begins with a fifteen
month $6.4 million award to develop the preliminary design and perform key
technology demonstrations. This modern rotorcraft, named by DARPA as the
"Heliplane" is designed to exploit GBA's gyrodyne technology, offering the
VTOL capability of a helicopter, the fast forward flight of an airplane, and
the safety, simplicity and reliability of a GBA gyroplane. This aircraft type
could be the next generation rotor wing aircraft, meeting economy and
performance goals not considered achievable by any other type of VTOL
aircraft.

DARPA is the central research and development organization for the US
Department of Defense (DoD). It manages and directs select basic and applied
research for DoD, emphasizing technology development projects where payoff is
high and where success may provide dramatic advances in the capabilities of
our combat forces.

"DARPA is a vastly diverse and capable organization charged with developing
the world's most advanced science in military technologies of every kind,"
said David Groen, President and CEO of Groen Brothers Aviation. "The DARPA
team is an amazing collection of scientists, engineers, and management and
administrative cadre, the likes of which have no equal. We are most impressed
with their dedication and are delighted with having been selected." "Our
Team," said Jay Groen, GBA's Chairman of the Board, "includes The Georgia
Institute of Technology, Adam Aircraft Industries, Williams International, and
a highly renowned team of aerospace consultants." Georgia Tech is a top U.S.
graduate engineering research university, with premier aerospace engineering
programs and its world famous rotary wing technology program. Adam Aircraft is
highly respected for its innovative use of modern composite materials,
engineering quality, and rapid prototyping processes that has allowed Adam to
bring to market two new high-performance aircraft: the six passenger
"center-line-twin" A500 and the A700 personal jet. Williams International has
developed more than 40 different small gas turbine engine systems for both
military and commercial air vehicles, including the Adam A700 and many other
modern "biz-jets."

The GBA contract with DARPA is based upon the "gyrodyne" concept long espoused
by Groen Brothers Aviation and extensively researched by Georgia Tech. A
gyrodyne is similar in appearance to a winged helicopter, and like a
helicopter is capable of hovering and vertical takeoff and landing. Unlike a
helicopter, however, a gyrodyne's rotor is driven by rotor blade reaction
drives and are powered only during hover, takeoff and landing. During forward
flight, like a gyroplane, the rotor is not powered, with forward thrust being
provided by engines typical of an airplane. This use of reaction drives for
rotor power and main engines for forward thrust eliminates the need for much
of the cost, weight, and complexity found in helicopters, while permitting
much higher forward speeds.

About Groen Brothers Aviation, Inc.

Developing gyroplane technology since 1986, GBA is recognized as the world's
leading authority on autorotative flight. The company has developed the
Rolls-Royce gas turbine engine powered Hawk 4, the world's first commercially
viable modern gyroplane - the first "autogiro" to utilize a jet engine. The
Hawk 4 Gyroplane was used extensively for security aerial patrol missions
during the 2002 Winter Olympics in Salt Lake City. The gyroplane's inherently
simple design offers a safe and affordable alternative to helicopters and
airplanes for many applications, including aerial observation roles in both
government and private applications, agricultural aerial application, tour
guide flights, and cargo/passenger transport. Through its American Autogyro
division, the company has also developed and is currently selling a smaller
kit gyroplane, the two seat "SparrowHawk," and developing a production two
seat gyroplane for the Light Sport Aircraft market. These designs also provide
a safe, extremely economical Airborne Patrol Vehicle (APV) for law enforcement
and other government applications. The Company continues to develop a
nationwide dealership network for the sale of these products. Further
information about the Company, its products, and individual members of the GBA
Team is available on the Company's web site at: www.gbagyros.com.

Safe Harbor Statement/Forward Looking Information Disclaimer

Certain statements in this news release by Groen Brothers Aviation are
forward-looking within the meaning of Section 27A of the Securities Act of
1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as
amended. Forward looking information is subject to risk and uncertainty.
Certain statements in this Press Release may contain forward looking
information that involves risk and uncertainty, including but not limited to,
the Company's ability to fund ongoing operations and to complete its
obligations under the government contract and its other ongoing commitments.
Future results and trends depend on a variety of factors, including the
Company's successful execution of internal performance plans; product
development and performance; risks associated with regulatory certifications
of the Company's commercial aircraft by U.S. and foreign governments;
government bid uncertainty; other regulatory uncertainties; performance issues
with key suppliers and subcontractors; governmental export and import
policies; and the ability to adequately finance operations including meeting
its debt obligations, fund manufacturing and delivery of products.

[Flyingmonk]

I'd pick the R44 over this anyday of the week.

[boB]

Flyingmonk wrote:

> I'd pick the R44 over this anyday of the week.
>

Just asking. Why?

--

boB,
SAG 70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)

[George Vranek]

Because it is able to hower. The ability to hower is the only reason why
people buy helicopters which are more complex, more expesive and slower than
fixed wing aircrafts.

George

"boB" > schrieb im Newsbeitrag
...
> Flyingmonk wrote:
>
> > I'd pick the R44 over this anyday of the week.
> >
>
> Just asking. Why?
>
> --
>
> boB,
> SAG 70
>
> U.S. Army Aviation (retired)
> Central Texas - 5NM West of Gray Army Airfield (KGRK)

[John A. Landry]

On Fri, 11 Nov 2005 00:42:34 +0100, in rec.aviation.rotorcraft, George Vranek
said:

>Because it is able to hower. The ability to hower is the only reason why
>people buy helicopters which are more complex, more expesive and slower than
>fixed wing aircrafts.

George,

You're right in that if there's a need to hover, for all practical purposes a
helicopter would be the aircraft of choice.

On the other hand, I think you're missing the point about the DARPA project as
described in the press release...

They aren't talking about a helicopter application. The press release said:
"...high speed, long range, vertical takeoff and landing (VTOL) aircraft..."
which doesn't sound like too many helicopters I've heard of.

But the "gyrodyne"... a hybrid aircraft arguably combining some of the best
aspects of a gyroplane, a helicopter, and possibly even a fixed wing
aircraft... could possibly fit the requirements. A gyrodyne has the ability
to takeoff and land vertically (though not likely hover accurately for
extended periods) and cruise at higher speeds using lower power than a
helicopter can.

If you think about it, maybe there are applications better suited to something
like a gyrodyne verses a helicopter or even a STOL fixed wing... like when
there's a need for both high cruising airspeeds and the ability to takeoff or
land from very small unimproved landing areas (ones with no runway).

I'm sure back when the automobile was first explored, some folks said: "I'll
take a horse any day."

Ya gotta keep an open mind. Just a thought!

Respectfully,

John L.
(Former Army helicopter pilot, and currently a gyroplane pilot.)

[boB]

> Ya gotta keep an open mind. Just a thought!
>
> Respectfully,
>
> John L.
> (Former Army helicopter pilot, and currently a gyroplane pilot.)

Hey John..... I don't recall the name but I was flying Army from 1970 -
1995. Even if we haven't met I'm sure our paths have crossed somewhere
along the line.

My dream was to build a RAF2000 Gyro, mostly because of the enclosed
cockpit and the standard type seating. I had even contacted an IP in
Pensacola about the training. I learned my lesson about thinking I
needed no new instruction after buying my Sprint II. that little guy
was a handful until I settled down. :) It flys so slow I felt like I
was hovering over the fields.

The RAF2000 would be as good as some small fixed wings with the only
drawback of lack of storage space with 2 people inside. That dream is
on hold now but what do you fly? I would like to hear your experiences.

http://flightsims.vze.com/raf2000

Take Care,

--

boB,
SAG 70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)

[Jim Carriere]

boB wrote:
> My dream was to build a RAF2000 Gyro, mostly because of the enclosed
> cockpit and the standard type seating. I had even contacted an IP in
> Pensacola about the training. I learned my lesson about thinking I

Bob (bOB? :), in the Pensacola neck of the woods there are about half a
dozen gyroplanes at the Brewton muni airport (about 50 miles north of PNS).

I come by this knowledge from passing within a few miles of Brewton last
year and talking with a gyroplane there on unicom. Since the gyro
community is a fairly small and tight, you may have already heard about
them.

[boB]

Jim Carriere wrote:

> boB wrote:
>
>> My dream was to build a RAF2000 Gyro, mostly because of the enclosed
>> cockpit and the standard type seating. I had even contacted an IP in
>> Pensacola about the training. I learned my lesson about thinking I
>
>
> Bob (bOB? :), in the Pensacola neck of the woods there are about half a
> dozen gyroplanes at the Brewton muni airport (about 50 miles north of PNS).
>
> I come by this knowledge from passing within a few miles of Brewton last
> year and talking with a gyroplane there on unicom. Since the gyro
> community is a fairly small and tight, you may have already heard about
> them.

:) boB... there are so many Bob's that I spell my name backwards. I
didn't know about Brewton. The IP I called was something like "dolph"
something. I wold have to go back through my folder on the gyro. I hope
some day to be flying again. Right now the pain medication I take is so
strong I don't even drive a car any more. My wife, bless her heart, did
not let me get in my ultralight even though I protested that flying it
was so easy I couldn't possibly get hurt. I sold it. But I can always
keep hoping.

My Toy
http://img247.imageshack.us/img247/3019/ultrastrip8lz.jpg
--

boB,
SAG 70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)

[B4RT]

"George Vranek" > wrote in message
...
> Because it is able to hower. The ability to hower is the only reason why
> people buy helicopters which are more complex, more expesive and slower
> than
> fixed wing aircrafts.
>
> George


The quote above means you have no understanding of why a helicopter is
useful.
I own two planes and a helicopter. The airplanes only take me to airports.
The
Jet Ranger can take me where I'm actually going.

I rarely have any need to hover.

Bart

[B4RT]

"George Vranek" > wrote in message
...
> Because it is able to hower. The ability to hower is the only reason why
> people buy helicopters which are more complex, more expesive and slower
> than
> fixed wing aircrafts.
>
> George


The quote above means you have no understanding of why a helicopter is
useful.
I own two planes and a helicopter. The airplanes only take me to airports.
The
Jet Ranger can take me where I'm actually going.

I rarely have any need to hover.

Bart

[B4RT]

"George Vranek" > wrote in message
...
> Because it is able to hower. The ability to hower is the only reason why
> people buy helicopters which are more complex, more expesive and slower
> than
> fixed wing aircrafts.
>
> George


The quote above means you have no understanding of why a helicopter is
useful.
I own two planes and a helicopter. The airplanes only take me to airports.
The
Jet Ranger can take me where I'm actually going.

I rarely have any need to hover.

Bart

[John A. Landry]

On Fri, 11 Nov 2005 21:36:35 GMT, in rec.aviation.rotorcraft, boB said:

>...I was flying Army from 1970 - 1995.

1982 to 1987 here.

>My dream was to build a RAF2000 Gyro, mostly because of the enclosed
>cockpit and the standard type seating.

Gyros are fun, simple, and affordable rotorcraft.

But no matter what model interests you, some strong words of caution to a
brother pilot...

There have been a lot of very poorly designed gyroplanes created over the
years (from a stability standpoint)... usually created by well meaning people
lacking an in depth understanding of both aerodynamics and physics. This has
lead to a lot of deaths and given amateur-built gyroplanes a bad reputation
that still lingers. Thankfully through better educated buyers, things have
been slowly changing.

Just as you should never buy any non-certified aircraft without first
researching it's safety and design stability, the same applies to gyroplanes.
The interesting thing about gyroplanes is that usually even an unstable one
can get in the air, but it's design flaws will be waiting to kill the
unsuspecting pilot under certain circumstances.

The bottom line is don't ever plunk down money on any gyroplane design until
you've done your research and fully understand the design stability issues and
choices. Don't take one persons word for it... especially if he's trying to
sell you something or has some other personal interest in steering your
decision (sometimes aircraft owners are the most deluded people you can find).
Your life depends on your choices!

Anyway, I don't mean to scare you off from gyroplanes... I just want to warn
you there are still unstable models out there.

And of course it goes without saying that you have to get proper and adequate
dual training before you ever attempt to operate a gyroplane solo. You'd be
surprised how many would-be pilots try to skip this important step for a
variety of not-so-good reasons.

A great place to learn more about gyroplanes is to hang out over on:

www.rotaryforum.com

>That dream is on hold now but what do you fly? I would like to hear your experiences.

I fly an open-frame single-place gyroplane called a GyroBee. I built it (from
free plans which can be downloaded on the Internet) staring in 1999, and I
finished in 2000. I have over 125 hours on it now.

You can see some pictures here (that's me flying at a dry lake bed this past
Labor Day weekend):

http://www.autorotation.net/GyroBee/Runup.jpg

http://www.autorotation.net/GyroBee/Circling.jpg

http://www.autorotation.net/GyroBee/Landing.jpg

It's a great little gyro and comfortable to operate.

Take care,

John L.

[boB]

John A. Landry wrote:

> On Fri, 11 Nov 2005 21:36:35 GMT, in rec.aviation.rotorcraft, boB said:
>
>
>>...I was flying Army from 1970 - 1995.
>
>
> 1982 to 1987 here.
>
>

I was at Ft Riley KS 82-85 then 2nd ACR in Germany through 1988


>
> But no matter what model interests you, some strong words of caution to a
> brother pilot...
>
> There have been a lot of very poorly designed gyroplanes created over the
> years (from a stability standpoint)... usually created by well meaning people
> lacking an in depth understanding of both aerodynamics and physics. This has
> lead to a lot of deaths and given amateur-built gyroplanes a bad reputation
> that still lingers. Thankfully through better educated buyers, things have
> been slowly changing.

thanks for the advice. When the time comes I'll be researching again.
Right now it's pilots like you that I like to talk with. the pictures
were great. Now that gyro looks a lot of fun to fly.

I've flown OH-58's across this county several times so a slow cruising
gyro is ok with me. I want the enclosed cockpit and ability to travel
cross country, albeit slowly. :)

>
> Anyway, I don't mean to scare you off from gyroplanes... I just want to warn
> you there are still unstable models out there.
>


Not at all scaring me.

>
> A great place to learn more about gyroplanes is to hang out over on:
>
> www.rotaryforum.com
>

I'll take a look... Thanks


>
> Take care,
>
> John L.

Thanks again....

--

boB,
SAG 70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)

[John A. Landry]

On Sat, 12 Nov 2005 01:43:01 GMT, in rec.aviation.rotorcraft, boB said:

>I was at Ft Riley KS 82-85 then 2nd ACR in Germany through 1988

I went right to Fort Lewis, WA after graduating from flight school in 1982,
and left the Army from there in 1987.

>I've flown OH-58's across this county several times so a slow cruising
>gyro is ok with me.

Cool! I flew 58's also in an AHB (Attack Helicopter Battalion) at Fort Lewis
before I snagged a medevac job for four years (in Huey's). Both were lots of
fun (loved the early NVG's flying Scouts), but I think I liked the medevac
better... more action.

My gyro cruises most comfortably at about 50-55 mph (in terms of smooth
handling and lower wind pressure on me), which is also about the max range
airspeed. When I'm in a hurry I'll fly around at 65 mph, but fuel economy
suffers. About 45 mph is the max endurance and best rate of climb airspeed.
70-75 mph is the max level flight speed at sea level and full power. Minimum
level flight speed is about 10-12 mph. Typical climb rate is 750 fpm at sea
level on a cool day and 500 fpm at sea level on a hot day. The highest I've
had it was 8000' msl, and at that point the climb rate had deteriorated to 100
fpm.

It burns about 4.0 to 4.5 gph average on a typical flight at 50-55 mph. At
full power, fuel consumption jumps up around 6-7 gph. My gyro has a 10 gallon
fuel tank, so if I'm conservative with the power settings, I can just fly for
2 hours with a reserve.

>I want the enclosed cockpit and ability to travel cross country, albeit slowly. :)

I live in Washington state, and sometimes I do wish I had a cockpit during the
long winters up here. But it's kinda funny... when the weather is nice, I've
gotten to where I much prefer being out in the open with the unrestricted
view! My hanger partner has an RAF-2000 gyro, and when I fly in that, I don't
like the way the cockpit blocks some of my view. I guess we all grow
accustomed to what we do the most... creatures of habit and all that.

Anyway, my next gyro will likely be a fully enclosed 2-place tractor
configuration.

>Thanks again....

My pleasure.

John L.

[Dave Jackson]

".... team to design a proof of concept high speed, long range, vertical
takeoff and landing (VTOL) aircraft designed for use in Combat Search and
Rescue roles. ........"

The above press release mentions 'Rescue'. Does not the landing and taking
off from difficulty locations, or the use of a winch, make the ability to
hover a necessary requirement?

Just a question.

[Jim Carriere]

Dave Jackson wrote:
> ".... team to design a proof of concept high speed, long range, vertical
> takeoff and landing (VTOL) aircraft designed for use in Combat Search and
> Rescue roles. ........"
>
> The above press release mentions 'Rescue'. Does not the landing and taking
> off from difficulty locations, or the use of a winch, make the ability to
> hover a necessary requirement?

I'd say yes, hover is absolutely a requirement, but not only because of
the landing and taking off part (you may not be able to land at all).

Speaking of only SAR, landing is usually most preferred, but not always
possible. The lack of ability to hover is a serious disadvantage. This
isn't rocket science either... think LZ considerations vegetation,
water, terrain, buildings...

If you land at all, no-hover landings and takeoffs are a consideration,
mainly to minimize blowing dust. A big disadvantage on landing is if
there is soft or irregular terrain or small obstacles. Think rocks,
tree stumps, gopher holes hidden by tall grass. The bottom of the
aircraft can be damaged, landing gear might get caught (result dynamic
rollover). Another option in soft terrain is to touchdown but not take
all the power off while personnel get in or get out of the aircraft. If
you're talking CSAR, you may not have time for a recce pass of the LZ,
and the final decision of if and how to touchdown may be made only a few
feet above landing. That is if there is an LZ at all.

Using a gyro for CSAR support, well, that may be worth consideration,
but it would involve rewriting some doctrine :)

Just a few of my thoughts.

[George Vranek]

Hi Bart,

You own two planes and a helicopter....
I am sure that www.diskrotor.com will be the right machine for you.

Regards George

"B4RT" > schrieb im Newsbeitrag
...
>
> The quote above means you have no understanding of why a helicopter is
> useful.
> I own two planes and a helicopter. The airplanes only take me to airports.
> The
> Jet Ranger can take me where I'm actually going.
>
> I rarely have any need to hover.
>
> Bart
>
>

[Kevin O'Brien]

On 2005-11-11 17:06:20 -0500, boB > said:

> :) boB... there are so many Bob's that I spell my name backwards. I
> didn't know about Brewton. The IP I called was something like "dolph"
> something.


That would be Dofin Fritts. I've flown with him. Like many of the guys
that instruct in standard (i.e. no hstab) RAF2ks he's somewhat
controversial in the industry. He does love and understand gyros,
although he has a blind spot about longitudinal stability, and I think
he'd be a good instructor.

He's based kind of on the FL/AL border. After all the Florida panhandle
is not Florida, it's where Alabama meets the sea!

> I wold have to go back through my folder on the gyro. I hope some day
> to be flying again. Right now the pain medication I take is so strong I
> don't even drive a car any more.

Hope that you recover from what ails you. If I'd known how much it hurt
to grow old I'd have taken even greater risks in my youth. When you're
feeling better, an alternative to the RAF is the AAI Sparrowhawk, made,
oddly enough, by the selfsame Groen Brothers of this thread.

http;//gbagyros.com/

They began by modifying the RAF design to have centreline thrust and
the thing has got a massive cruciform tail, so it "hunts" a lot less in
the air. Their cabin is larger but it's not really a luggage hauler
either. There are a bunch of detail changes, like bucket seats that
adjust normally instead of a fixed seat/tank and adjustable pedals, and
all the patented RAF doo-hickeys like their mast folding arrangement
are not included.

A complete kit is just under $40k, ready to fly about $67k as a light
sport aircraft. It appears to be racking up a better safety record than
RAF -- RAF just lost another experienced CFI in canada, poor fellow --
but "anything that takes you up as high as a stepladder can kill ya."
And of course, there are maybe 70 AAI kits out there, as opposed to at
least 600, maybe more, RAF 2000s.

If you're in P'cola, the nearest AAI dealer to you is probably Terry
Eiland in the Tampa area.

> My Toy
> http://img247.imageshack.us/img247/3019/ultrastrip8lz.jpg

That page made me grin ;)
--
cheers

-=K=-

Rule #1: Don't hit anything big.

[boB]

Kevin O'Brien wrote:

> On 2005-11-11 17:06:20 -0500, boB > said:
>
>> :) boB... there are so many Bob's that I spell my name backwards. I
>> didn't know about Brewton. The IP I called was something like "dolph"
>> something.
>
> >
> That would be Dofin Fritts. I've flown with him.
>

That's him....


> an alternative to the RAF is the AAI Sparrowhawk, made,
> oddly enough, by the selfsame Groen Brothers of this thread.
>
> http;//gbagyros.com/
>

Thank you for the link. Now I have some time to look at it and from
what you say I would need a flight in each before buying.

>
> If you're in P'cola, the nearest AAI dealer to you is probably Terry
> Eiland in the Tampa area.
>

I'm quite a distance away here in Central Texas. It's a day plus trip
to p'cola


>> My Toy
>> http://img247.imageshack.us/img247/3019/ultrastrip8lz.jpg
>
>
> That page made me grin ;)

That was a fun little aircraft. I always had the feeling of a slow
hovering helicopter when flying it.

Thanks for the information, I really appreciate it.

--

boB,
SAG 70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)

[Shiver]

> an alternative to the RAF is the AAI Sparrowhawk, made,
> oddly enough, by the selfsame Groen Brothers of this thread.

http://gbagyros.com/

Well I'm just an armchair pilot folks.....

So correct me if I am wrong.

It's unfortunate that Ken Sandy EGGO isn't kicking around the group
these days, as I'm sure he would have jumped into this thread by now.

He lives in San Diego and has been flying Gyros for years.

He is a big big champion of the vertical (centerline) stabilizer on
gyros and I do believe has had his share of arguements with the
developers of the RAF gyros on this subject. He has talked about the
dangers of buntover with resulting death in this group at various
times.

If my feeble memory is correct a few years ago Ken sent his unit
to Groen brothers and had some conversion work done by them, which
they mention on their website

http://www.americanautogyro.com/Photo%20Gallery/Photo%20Gallery.htm

Scroll down the photo page to see pix and surf their website for
written info.

[Shiver]

> The OTHER Kevin in San Diego wrote:

> He doesn't fly a white Gyro out of KSEE (Gillespie Field) does he???

SEEK AND YOU SHALL FIND.... Or something like that.

Just had a peek at an older browser I once used and there it was.

http://www.geocities.com/kenj_sandyeggo/KensWebPage.html

Yupper's.... It's white.

Unfortunately it's been a few years since he's updated his page and
it's been a couple of years since he was a regular here.

[boB]

Shiver wrote:

> He is a big big champion of the vertical (centerline) stabilizer on
> gyros and I do believe has had his share of arguements with the
> developers of the RAF gyros on this subject. He has talked about the
> dangers of buntover with resulting death in this group at various
> times.

Buntover??? In my reading I haven't run across that term. I know how to
keep from causing the normal spike knock, tail boom strikes, 0 G pitch
down and mast bumping problems. From the word, is it a forward
pitchover caused by the horizontal stabilizer being too low?

--

boB,
SAG 70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)

[Shiver]

> boB > wrote:

> Buntover??? In my reading I haven't run across that term. I know how to
> keep from causing the normal spike knock, tail boom strikes, 0 G pitch
> down and mast bumping problems. From the word, is it a forward
> pitchover caused by the horizontal stabilizer being too low?

From the Groen Brothers website

http://www.americanautogyro.com/Centerline%20Thrust/Centerline%20Thrust%
20P1.htm

Watch for the URL wraparound

It's described in the first couple of paragraphs.

That link by the way is about four pages long and is interesting
reading.

If my feeble memory serves me correctly.... Oh Mr. Sandy Eggo where are
you......

Ken bought an RAF gyro that did not have a vertival stabilzer.

Correct me if I am wrong.

He became aware of various accidents involving buntover due to no
stabilizer and many of those pilots were killed or seriously injured.

As a result he became a convert to the idea of having a centerline
stabilzer added ( with dihedral I do believe ).

He got into arguements with the RAF people who I presume did not feel
it was necessary.

When Groen brothers offered a factory kit for his RAF gyro he sent it
off to them for upgrading and as far as I know he is a very satisfied
customer.

[boB]

Shiver wrote:
>>boB > wrote:
>
>
>>Buntover??? In my reading I haven't run across that term. I know how to
>>keep from causing the normal spike knock, tail boom strikes, 0 G pitch
>>down and mast bumping problems. From the word, is it a forward
>>pitchover caused by the horizontal stabilizer being too low?
>
>
> From the Groen Brothers website
>
> http://www.americanautogyro.com/Centerline%20Thrust/Centerline%20Thrust%
> 20P1.htm
>
> Watch for the URL wraparound
>
> It's described in the first couple of paragraphs.
>
> That link by the way is about four pages long and is interesting
> reading.
>
> If my feeble memory serves me correctly.... Oh Mr. Sandy Eggo where are
> you......
>
> Ken bought an RAF gyro that did not have a vertival stabilzer.
>
> Correct me if I am wrong.
>
> He became aware of various accidents involving buntover due to no
> stabilizer and many of those pilots were killed or seriously injured.
>
> As a result he became a convert to the idea of having a centerline
> stabilzer added ( with dihedral I do believe ).
>
> He got into arguements with the RAF people who I presume did not feel
> it was necessary.
>
> When Groen brothers offered a factory kit for his RAF gyro he sent it
> off to them for upgrading and as far as I know he is a very satisfied
> customer.

Thanks. I'll do some reading

--

boB,
SAG 70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)

[Shiver]

> The OTHER Kevin in San Diego wrote:

> so chances are I've seen Ken terrorizing the airspace down there
> within the past year. :)

Well if you ever run into him tell him to stick his head into the group
now and again and say howdy hi.

He was a well know and respected regular a few years ago.

Here's hoping he's spending lots of his free time flying up and down
the coast in his gyro.

[Shiver]

> The OTHER Kevin in San Diego wrote:

> but I don't stay
> local much at all these days when I fly..

I was a little surprised when I was surfing Groen's site yesterday
and looked at the pricing info on the sparrowhawk kits.

35 thousand buckies seems kinda reasonable for a kit built gyro.

Have you ever considered a beast like that.

Seems like the main difference between that and a helicopter is you
can't take off vertical, and you can't hover.

[John A. Landry]

On Fri, 18 Nov 2005 12:12:43 -0800, in rec.aviation.rotorcraft, The OTHER
Kevin in San Diego <skiddz "AT" adelphia "DOT" net> said:

>>Well if you ever run into him tell him to stick his head into the group
>>now and again and say howdy hi.

Within the past year Ken J. sold his Sparrowhawk converted RAF-2000 gyroplane
and bought a very nice FAA certified McCullough J2 gyroplane. Last I heard he
was considering getting a commercial gyroplane rating.

Regards,

John L.

[Shiver]

> John A. Landry > wrote:

> Within the past year Ken J. sold his Sparrowhawk converted RAF-2000 gyroplane
> and bought a very nice FAA certified McCullough J2 gyroplane. Last I heard he
> was considering getting a commercial gyroplane rating.

Well it's nice to hear he's still flying.

Next time you see him tell him we miss him.

Sheeeeeesh... I just Googles McCullough J2 gyroplane
and the info on the little beast is sure skimpy.

Found one mediocre picture buried in a page.

Anyone got a URL for their website.

Please and thank you.

[Steve R]

"boB" > wrote in message
...
> Shiver wrote:
>
>> He is a big big champion of the vertical (centerline) stabilizer on
>> gyros and I do believe has had his share of arguements with the
>> developers of the RAF gyros on this subject. He has talked about the
>> dangers of buntover with resulting death in this group at various
>> times.
>
> Buntover??? In my reading I haven't run across that term. I know how to
> keep from causing the normal spike knock, tail boom strikes, 0 G pitch
> down and mast bumping problems. From the word, is it a forward pitchover
> caused by the horizontal stabilizer being too low?
>
> --
>
> boB,
> SAG 70

Buntover is just another term for a power push over (PPO). From what I've
gathered in my reading through the years, it's not as much an issue with the
horizontal stabilizer as it is with the placement of the engines thrust line
relative to the vertical CG of the aircraft. Gyros like the stock RAF2000
have the thrust line at a significant distance above the vertical CG of the
aircraft. That imparts a nose down moment when under power. The main
rotor, because it's tilted aft in flight, offers a counter force to the
forward pitching moment. If you unload the main rotor enough, there's not
counter force to that forward pitching moment caused by the engine thrust
line being above the CG and over she goes.

A properly placed and sized horizontal stab can go a long way toward
reducing the possibility of this problem but it doesn't address the root
cause. That being a thrust line that's not properly in line with the
vertical CG of the aircraft. At least that's my understanding. If I'm too
far off on this, I'm sure someone will correct me! :-)

Fly Safe,
Steve R.

[boB]

Steve R wrote:
> "boB" > wrote in message
> ...
>
>>Shiver wrote:
>>
>>
>>>He is a big big champion of the vertical (centerline) stabilizer on
>>>gyros and I do believe has had his share of arguements with the
>>>developers of the RAF gyros on this subject. He has talked about the
>>>dangers of buntover with resulting death in this group at various
>>>times.
>>
>>Buntover??? In my reading I haven't run across that term. I know how to
>>keep from causing the normal spike knock, tail boom strikes, 0 G pitch
>>down and mast bumping problems. From the word, is it a forward pitchover
>>caused by the horizontal stabilizer being too low?
>>
>>--
>>
>>boB,
>>SAG 70
>
>
> Buntover is just another term for a power push over (PPO). From what I've
> gathered in my reading through the years, it's not as much an issue with the
> horizontal stabilizer as it is with the placement of the engines thrust line
> relative to the vertical CG of the aircraft. Gyros like the stock RAF2000
> have the thrust line at a significant distance above the vertical CG of the
> aircraft. That imparts a nose down moment when under power. The main
> rotor, because it's tilted aft in flight, offers a counter force to the
> forward pitching moment. If you unload the main rotor enough, there's not
> counter force to that forward pitching moment caused by the engine thrust
> line being above the CG and over she goes.
>
> A properly placed and sized horizontal stab can go a long way toward
> reducing the possibility of this problem but it doesn't address the root
> cause. That being a thrust line that's not properly in line with the
> vertical CG of the aircraft. At least that's my understanding. If I'm too
> far off on this, I'm sure someone will correct me! :-)
>
> Fly Safe,
> Steve R.
>
>

Thanks Steve. That sounds like two forces working against each other.
That doesn't seem to be efficient as far as strain on the systems.
Something similar on my Sprint II with the engine and prop above the
vertical CG. If the engine quits or even when throttling down the nose
pops up which screwed up my landings early on. I had been fixed on the
RAF2000 but hadn't really looked at the competition before. I
appreciate all the advice.


--

boB,
SAG 70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)

[Steve R]

"boB" > wrote in message
...
>
> Thanks Steve. That sounds like two forces working against each other. That
> doesn't seem to be efficient as far as strain on the systems. Something
> similar on my Sprint II with the engine and prop above the vertical CG. If
> the engine quits or even when throttling down the nose pops up which
> screwed up my landings early on. I had been fixed on the RAF2000 but
> hadn't really looked at the competition before. I appreciate all the
> advice.
>
> boB,
> SAG 70

Your welcome Bob! You're right, these forces are working against each
other, and not in a good way. Designs like this have been flown for years
and there are still people out there that insist that it's perfectly safe.
They may have learned to deal with it but the unfortunate fact is that too
many people have died because of the high thrust line designs that didn't
have to.

Personally, I wouldn't touch an RAF2000 with a 10 foot pole but the Groen
Bros version of it looks like a very nice alternative if you've really got
your heart set on a fully enclosed cabin. Of the more open designs around,
I'm really impressed with the Air Command. They are one of the few kit
manufacturers that had the guts and integrity to completely redesign their
gyros when it finally became clear what the high thrust line issues were
doing to the aircrafts stability. They don't sell anything now that's not
centerline thrust and they offer a very reasonable upgrade kit for those who
still have the older high thrust line gyros sitting in the barn. They also
issued, if I'm not mistaken, and air worthiness directive to all owners of
the old high thrust line machines, advising them to "not" fly until it's
been converted to centerline thrust!

Are you familiar with the PRA (Popular Rotorcraft Association)? They can be
found at www.pra.org and are a great source of info on experimental gyros
and helicopters. Also, check out this forum if you're not already familiar
with it,

http://www.rotaryforum.com/index.php

Lots of really great people and good information. Just be aware that the
gyro folks can be, shall we say, "passionate," about their machines so it
sometimes helps to have a thick skin around there. ;-)

Best of luck,
Steve R.

[boB]

Steve R wrote:

> Lots of really great people and good information. Just be aware that the
> gyro folks can be, shall we say, "passionate," about their machines so it
> sometimes helps to have a thick skin around there. ;-)
>
> Best of luck,
> Steve R.

Thanks Steve. I really hope someday to fly again. Until then I have a
lot of time to research. I'm very glad I found you all.
--

boB,
SAG 70

U.S. Army Aviation (retired)
Central Texas - 5NM West of Gray Army Airfield (KGRK)

[Flyingmonk]

Because for $749,000.00, I can buy two working helicopters that will do
what the Hawk 4 will do plus hover. ; < )