Groen Bros. DARPA Award

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/img247/3...rastrip8lz.jpg
--

boB,
SAG 70

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

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/img247/3...rastrip8lz.jpg

That page made me grin
--
cheers

-=K=-

Rule #1: Don't hit anything big.

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/img247/3...rastrip8lz.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)

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/Phot...%20Gallery.htm

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

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)

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/Cent...line%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.

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/Cent...line%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)

"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.

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)