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15 mph Stol whats the name Peg?



 
 
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  #1  
Old September 14th 03, 09:19 AM
Roland M
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Default 15 mph Stol whats the name Peg?

I heard of a tail drager Canada? USA? with an amazing 15mph stall
anyone know, kit/plans/manufactured, still in buisness?
Thanks Roland
  #2  
Old September 14th 03, 06:43 PM
clare @ snyder.on .ca
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On Sun, 14 Sep 2003 10:59:15 GMT, Kevin Horton
wrote:

On Sun, 14 Sep 2003 02:19:01 -0700, Roland M wrote:

I heard of a tail drager Canada? USA? with an amazing 15mph stall anyone
know, kit/plans/manufactured, still in buisness? Thanks Roland


That sounds like the Pegazair. Their web site lists the VSO for the
Pegazair P-80 as 23 mph, with the minimum controllable speed as 15 mph,
whatever that means.

Even a VSO of 23 mph is hard to believe, with a weight of 1200 lb and a
wing area of 150 sq. ft. That implies a CL of 5.9 which doesn't seem
credible to me. 15 mph implies a CL of 13.9, although some of the weight
is probably being supported by power in this case, so the actual CL
required would be a bit less.

I suspect the quoted specs are IAS numbers, which are pretty much
meaningless given the usual position errors at high angle of attack. I
fly a C182 that will fly at less than 30 kt IAS, but I don't believe for a
minute that the airspeed is really anywhere close to 30 kt CAS.

See: http://www.tapanee.com/index.html

You'll have to click the little "English" button near the top left of the
page, as the company is based in Quebec, and most of their sales are in
Quebec.

It is interesting to compare the claimed performance against the CLs that
Chris Heintz quotes. He claims he gets a CL max of 3.3 with leading edge
slats plus flaps, which is in line with various wind tunnel studies I have
seen.

http://www.zenithair.com/stolch801/design/design.html

The claimed performance of the Zenair CH-801 implies a CL max of 3.3
(stall speed of 39 mph at 2,150 lb weight with 167 ft^2 of wing area).

http://www.zenithair.com/stolch801/performance.html


In a 20 knott headwind the Peg will hover under power at a fairly
steep angle. In a 30 knott wind it can be backed onto the runway. It
is similar to a scale Helio Courier. It has automatic leading edge
slats and full span flaperons. Gross weight is 1420 lbs.

I am building one.
  #3  
Old September 14th 03, 09:05 PM
Kevin Horton
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On Sun, 14 Sep 2003 18:43:01 +0000, clar wrote:

In a 20 knott headwind the Peg will hover under power at a fairly steep
angle. In a 30 knott wind it can be backed onto the runway. It is
similar to a scale Helio Courier. It has automatic leading edge slats
and full span flaperons. Gross weight is 1420 lbs.

I am building one.


Do you know how light you need to be to truly hover in that 20 kt wind?
Have you actually seen this, or only heard about it? Where did the
reported wind speed come from? Estimated wind speed, hand held anemometer
or calibrated airfield anemometer?

There is a fairly steep wind gradient in the first few feet above the
ground, so if the reported wind speed comes from an anemometer at say 6 ft
AGL, the wind speed at say 50 ft AGL would be a fair bit higher. The data
from airfield anemometers is corrected to report what the wind would be at
10 meters AGL.

For altitudes above 5 ft, the standard correction for wind speeds is W2 =
W1 * (H2/H1)^(1/7), where W1 is the measured wind speed at height H1 and
W2 is the corrected wind speed at height H2.

How far along is your project? Where are you located? I'm looking
forward to seeing it fly someday.

--
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://go.phpwebhosting.com/~khorton/rv8/

  #4  
Old September 14th 03, 09:35 PM
clare @ snyder.on .ca
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On Sun, 14 Sep 2003 20:05:59 GMT, Kevin Horton
wrote:

On Sun, 14 Sep 2003 18:43:01 +0000, clar wrote:

In a 20 knott headwind the Peg will hover under power at a fairly steep
angle. In a 30 knott wind it can be backed onto the runway. It is
similar to a scale Helio Courier. It has automatic leading edge slats
and full span flaperons. Gross weight is 1420 lbs.

I am building one.


Do you know how light you need to be to truly hover in that 20 kt wind?
Have you actually seen this, or only heard about it? Where did the
reported wind speed come from? Estimated wind speed, hand held anemometer
or calibrated airfield anemometer?


At gross all it takes is horsepower. Mine will be below 120HP, so I
don't plan on trying it. However, my partner in the plane flew with
the designer and the guys on the ground saw the plane fly backwards.
The guy flys Beavers for a living. Indicated airspeed was 0.. Not sure
how they read the airspeed, but I'd trust that it was close. I HAVE
seen a Courier land backwards at the JAARS airfiels at Waxhaw N.
Carolina.

There is a fairly steep wind gradient in the first few feet above the
ground, so if the reported wind speed comes from an anemometer at say 6 ft
AGL, the wind speed at say 50 ft AGL would be a fair bit higher. The data
from airfield anemometers is corrected to report what the wind would be at
10 meters AGL.

For altitudes above 5 ft, the standard correction for wind speeds is W2 =
W1 * (H2/H1)^(1/7), where W1 is the measured wind speed at height H1 and
W2 is the corrected wind speed at height H2.

How far along is your project? Where are you located? I'm looking
forward to seeing it fly someday.

Located in Kitchener Waterloo area of Ontario. Fuselage is on the
table in my partner's garage (air conditioned) being welded. Tail
peices (rudder and stab etc) ready for closing. We have the spar
material cut and ready to assemble, and all ribs ready. The wings will
go together over the winter in my partner's basement.
The engine, a 1965 Corvair , is mostly completed, and has several
hours of ground running on a 68" Ivo Magnum. May be replacing the
camshaft in the future. Suspect we have an honest 80HP as it sits. 100
would be nice.
Likely another 2 years assembly time required.
  #5  
Old September 14th 03, 10:36 PM
Mark Hickey
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clare @ snyder.on .ca wrote:

At gross all it takes is horsepower. Mine will be below 120HP, so I
don't plan on trying it. However, my partner in the plane flew with
the designer and the guys on the ground saw the plane fly backwards.
The guy flys Beavers for a living. Indicated airspeed was 0.. Not sure
how they read the airspeed, but I'd trust that it was close.


Either you meant "ground speed", or they've finally figured out that
pesky anti-gravity device (or I suppose, are turning a really, REALLY
big prop with a really, REALLY big engine and standing the thing on
its tail...).

Mark Hickey
  #6  
Old September 14th 03, 10:43 PM
Kevin Horton
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On Sun, 14 Sep 2003 22:36:40 +0000, Mark Hickey wrote:

clare @ snyder.on .ca wrote:

At gross all it takes is horsepower. Mine will be below 120HP, so I
don't plan on trying it. However, my partner in the plane flew with the
designer and the guys on the ground saw the plane fly backwards. The guy
flys Beavers for a living. Indicated airspeed was 0.. Not sure how they
read the airspeed, but I'd trust that it was close.


Either you meant "ground speed", or they've finally figured out that
pesky anti-gravity device (or I suppose, are turning a really, REALLY
big prop with a really, REALLY big engine and standing the thing on its
tail...).

Mark Hickey


Just another example of the errors in indicated airspeeds at high angles
of attack.

--
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://go.phpwebhosting.com/~khorton/rv8/

  #7  
Old September 15th 03, 01:14 AM
Kevin Horton
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On Sun, 14 Sep 2003 23:53:18 +0000, Dave Hyde wrote:

Kevin Horton wrote:

Just another example of the errors in indicated airspeeds at high
angles of attack.


You're more generous than I. Performance numbers, particularly at low
speed/high AOA, presented in terms of *indicated* airspeed are useless.

Dave 'position error' Hyde


Yeah, it is amazing how many people don't understand that. Up here in
Canada we have a class of aircraft called Advanced-Ultralights. Sort of a
Piper Cub class of aircraft. The responsibility for the design standards
was handed to the Transport Canada Maintenance and Manufacturing folks
(i.e. A&Ps). I think the powers that be figured the folks who are
responsible for all the Type Certificated aircraft design standards (i.e.
Aircraft Certification) were philisophically incapable of writing a
"simple" design standard. Anyway, the Advanced-Ultralight design
standards require a stall speed of 39 kt Indicated Airspeed or less.
Indicated Airspeed. Amazing.

I betcha I could get a 747 to stall at 39 KIAS if you let me mess around
with the location of the static ports and the locatation and orientation
of the pitot tube.

When I was working on the Diamond DA-20-C1 program, Diamond spent a long
time trying to fine tune the pitot-static system. They had a good system
on the DV-20, but they had made a change in the spar design which forced
them to move the pitot-static tube. They decided on a location and then
messed around with the angle on the bottom of the Piper type pitot-static
tube. One of the variations they tested indicated about 10 kt low at the
stall and about 20 kt high in cruise. We joked about selling that
pitot-static tube as a high-performance option.

--
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://go.phpwebhosting.com/~khorton/rv8/

  #8  
Old September 15th 03, 07:46 PM
clare @ snyder.on .ca
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On Sun, 14 Sep 2003 21:36:40 GMT, Mark Hickey
wrote:

clare @ snyder.on .ca wrote:

At gross all it takes is horsepower. Mine will be below 120HP, so I
don't plan on trying it. However, my partner in the plane flew with
the designer and the guys on the ground saw the plane fly backwards.
The guy flys Beavers for a living. Indicated airspeed was 0.. Not sure
how they read the airspeed, but I'd trust that it was close.


Either you meant "ground speed", or they've finally figured out that
pesky anti-gravity device (or I suppose, are turning a really, REALLY
big prop with a really, REALLY big engine and standing the thing on
its tail...).

Mark Hickey

No, the little airspeed indicator on the wing said zero - due to the
extreme angle of attack. When I said not sure how they measured the
airspeed I meant wind speed. It was something around 20 IIRC.
  #9  
Old September 15th 03, 11:58 PM
Dave Hyde
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clare, @, snyder.on, .ca wrote:

No, the little airspeed indicator on the wing said zero - due to the
extreme angle of attack.


Without passing judgement on the performance you've
stated, I'll say that with a screwdriver and maybe
a sharp knife or tubing cutter and maybe a little
duct tape I can make *any* pitot-static based
airspeed indicator read zero at *any* airspeed.
Indicated airspeed tells you little if anything
asbout what the airplane is *really* doing.

Dave 'PSI differential' Hyde

 




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