tuft testing

[keepitrunning]

I was reading and saw a picture of a wing being tuft tested. I was
wondering, since I do not have a clue, how much difference the tape holding
the tufts would cause. In the picture it appears that 1/2 inch blue masking
tape was used and it was torn rather than cut. The tufts were spaced a
couple of inches apart and there were seven rows and eight columns. His
results were that the wing was not showing any separation. Just wondering
if there are accepted methods of doing this type of testing? How would you
determine where to test? Any discussion and comments would be appreciated.

[Stealth Pilot]

On Wed, 27 Oct 2004 15:56:11 GMT, "keepitrunning" >
wrote:

>I was reading and saw a picture of a wing being tuft tested. I was
>wondering, since I do not have a clue, how much difference the tape holding
>the tufts would cause. In the picture it appears that 1/2 inch blue masking
>tape was used and it was torn rather than cut. The tufts were spaced a
>couple of inches apart and there were seven rows and eight columns. His
>results were that the wing was not showing any separation. Just wondering
>if there are accepted methods of doing this type of testing? How would you
>determine where to test? Any discussion and comments would be appreciated.
>
tufting is useful for checking that flows are remaining laminar and in
trying to identify drag sources due to turbulence.

you use a tape which can be peeled off without ripping up the paint.
vinyl gaffer tape is ideal. the wool is any contrasting colour and at
about 8ply thickness. the tuft is about 6-8 inches long.

you tape about an inch or so of the wool. the tape should remain
within the boundary layer with the wool getting out into the airstream
eventually.

accepted methods? nah, use whatever works. it isnt rocket science.

where to test? anywhere which looks like further improvement is
possible. it should be obvious but you need to tuft where you can see
or photograph the tufts. if you cant see the tufts you will need
another aircraft to formate in flight.

what do you find out? well sometimes nothing but often you get to see
what the air is doing.

try a few tufts on the bonnet and windscreen of your car.
Stealth Pilot

[sidk]

Here is a link to a photo from last month's tuft-testing on my
Velocity with hopes that some clue would appear as to why my engine
cooling is worse than marginal. Tape was duct tape and some was on
for several months (waiting for weather, photographer, digital camera,
photoplane, etc...) and was a pain-in-the-butt to remove.
For the test, the left (pilot) side NACA has two VGs, the right side
none.

http://img35.exs.cx/img35/5182/HPIM0430.jpg

Sid Knox

Velocity N199RS
Starduster N666SK
KR2 N24TC
W7QJQ

http://img35.exs.cx/img35/5182/HPIM0430.jpg

"keepitrunning" > wrote in message >...
> I was reading and saw a picture of a wing being tuft tested. I was
> wondering, since I do not have a clue, how much difference the tape holding
> the tufts would cause. In the picture it appears that 1/2 inch blue masking
> tape was used and it was torn rather than cut. The tufts were spaced a
> couple of inches apart and there were seven rows and eight columns. His
> results were that the wing was not showing any separation. Just wondering
> if there are accepted methods of doing this type of testing? How would you
> determine where to test? Any discussion and comments would be appreciated.

[Morgans]

"sidk" > wrote in message
om...
> Here is a link to a photo from last month's tuft-testing on my
> Velocity with hopes that some clue would appear as to why my engine
> cooling is worse than marginal. Tape was duct tape and some was on
> for several months (waiting for weather, photographer, digital camera,
> photoplane, etc...) and was a pain-in-the-butt to remove.
> For the test, the left (pilot) side NACA has two VGs, the right side
> none.
>
> http://img35.exs.cx/img35/5182/HPIM0430.jpg
>
> Sid Knox
>
> Velocity N199RS
> Starduster N666SK
> KR2 N24TC
> W7QJQ
>
> http://img35.exs.cx/img35/5182/HPIM0430.jpg

Interesting. I'm sure you have researched the data that shows NACA
submerged inlets are poor at cooling applications, where the pressure
required for good flow, are relatively high?

Wouldn't a scoop, ala upside-down P-51 scoop do much better, with low drag,
also?

Did you try naphtha, (lighter fluid)?

I made the mistake of leaving duct tape on a vehicle too long once, and I
commiserate. Slow steady progress with plenty of naphtha and paper towels,
was my best way out.
--
Jim in NC


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.782 / Virus Database: 528 - Release Date: 10/22/2004

[Corky Scott]

On 27 Oct 2004 17:43:27 -0700, (sidk) wrote:

>Here is a link to a photo from last month's tuft-testing on my
>Velocity with hopes that some clue would appear as to why my engine
>cooling is worse than marginal. Tape was duct tape and some was on
>for several months (waiting for weather, photographer, digital camera,
>photoplane, etc...) and was a pain-in-the-butt to remove.
>For the test, the left (pilot) side NACA has two VGs, the right side
>none.
>
>http://img35.exs.cx/img35/5182/HPIM0430.jpg
>
>Sid Knox
>
>Velocity N199RS

Sid, I hope that there are some other scoops somewhere besides the two
I see on top of the airplane. From what I've read over the years if
the two scoops I see are it for cooling, there are two really glaring
problems. 1. Naca scoops are really marginal for engine cooling
intakes, this is something that has been known for many years. 2.
Naca scoops do not work when placed in a low pressure region of the
fuselage. Your two scoops are on the downside of the rear of the
fuselage and for sure are in a low pressure area.

What works? Pitot type scoops placed in an area of positive pressure,
or out in the free air stream ala P-51 Mustang.

But if you have pitot type scoops on the belly of your airplane,
nevermind.

Corky Scott

[sidk]

Yes, I have some literature discussing the misapplication of these
submerged NACA inlets. Unfortunately, the previous owner/builder
installed them because the original scheme(s) were apparently worse.
I am willing to tradeoff a little extra drag for better cooling... I
am just not certain yet how best/easiest to do it.
I'll try the naptha.. thanks.

Sid

>
> Interesting. I'm sure you have researched the data that shows NACA
> submerged inlets are poor at cooling applications, where the pressure
> required for good flow, are relatively high?
>
> Wouldn't a scoop, ala upside-down P-51 scoop do much better, with low drag,
> also?
>
> Did you try naphtha, (lighter fluid)?
>
> I made the mistake of leaving duct tape on a vehicle too long once, and I
> commiserate. Slow steady progress with plenty of naphtha and paper towels,
> was my best way out.

[Rich S.]

"sidk" > wrote in message
om...
> Yes, I have some literature discussing the misapplication of these
> submerged NACA inlets. Unfortunately, the previous owner/builder
> installed them because the original scheme(s) were apparently worse.
> I am willing to tradeoff a little extra drag for better cooling... I
> am just not certain yet how best/easiest to do it.
> I'll try the naptha.. thanks.

You might give Goof-off http://www.valspar.com/val/resident/goof-off.jsp a
try.

I had to remove and replace an adhesive wing walk about 12" x 36" which had
been on the plane for three years. A little heat from a hair dryer allowed
the black stuff to peel off, but there was a thin film of adhesive
remaining.

Every solvent I tried either wouldn't touch the adhesive - or would dissolve
it for a moment until the solvent started to evaporate, then it would gel
again. The fumes from the various solvents (Alcohol, Mineral spirits,
Naphtha, Enamel reducer, Lacquer thinner, Xylol, & Acetone) weren't doing my
already-abused liver any favors, either!

The Goof-off didn't tend to evaporate and the citrus odor was a lot less
bothersome. It loosened the adhesive so I was able to remove it with a soft
plastic scraper. I used a whole roll of paper towels to wipe the resulting
"boogers" off the scraper!

A can of Goof-off is now standard equipment in the hangar.

Rich S.

[Russell Kent]

Sid wrote:
> Yes, I have some literature discussing the misapplication of these
> submerged NACA inlets. Unfortunately, the previous owner/builder
> installed them because the original scheme(s) were apparently worse.
> I am willing to tradeoff a little extra drag for better cooling... I
> am just not certain yet how best/easiest to do it.

OK, Jim Morgan's comment about submerged NACA ducts are "poor at cooling
applications" is perhaps overly broad. The NACA papers actually say they
are poor choices to feed air to heat exchangers, also known as radiators and
oil coolers. They are silent as to their application for cooling air to
traditional "air cooled" (I hat that term) engines.

But nonetheless, I'd like to add my speculation (it *is* Usenet y'know ;-)

The builder's choice of submerged NACA ducts seems to have several things
working against it in this case:

1. The photo seems to show submerged ducts, but they seem exceedingly narrow
and improperly proportioned compared to my recollection of the drawings of
the original submerged NACA ducts. How likely is it that the builder's
ducts are versions of actual tested NACA ducts and not some random ducts
that the builder preferred?

2. Any air inlet, NACA or not, works best when the inlet is positioned in a
(relatively) high air pressure region, and works poorly or even in reverse
when placed in a (relatively) low air pressure region. I do not have a
pressure region map for the Velocity, but you as an owner/(re-)builder have
access to more information than I. See if you can locate a pressure map.
Just speculating, the site just aft of the point of greatest fuselage height
(where the ducts are now) seems like a local *low* pressure area.

3. Submerged NACA ducts work abysmally in areas of turbulent separation of
flow. The photo seems to indicate that turbulent separation is occuring at
the rear door seam. If you need air, and you're constrained to get it from
an area of turbulent separation, then there are only two choices: either the
thing that wants the air better be at substantially lower air pressure than
the turbulent area, or you use a scoop with a standoff to keep the turbulent
boundary layer out of the captured air.

4. The position of the existing ducts suggests that the engine uses
downdraft cooling, i.e. the cooling air is introduced on the top side of the
cylinders and pressures are used to force it out the bottom side of the
cylinders. Downdraft cooling is prone to problems at low airflow velocities
because of the tendency of heated air to rise. Low airflow velocities tend
to coincide, unfortunately, with situations that need the best possible
cooling, namely climbs (high power, low airspeed).

Regards,
Russell Kent

[Blueskies]

"sidk" > wrote in message om...
> Here is a link to a photo from last month's tuft-testing on my
> Velocity with hopes that some clue would appear as to why my engine
> cooling is worse than marginal. Tape was duct tape and some was on
> for several months (waiting for weather, photographer, digital camera,
> photoplane, etc...) and was a pain-in-the-butt to remove.
> For the test, the left (pilot) side NACA has two VGs, the right side
> none.
>
> http://img35.exs.cx/img35/5182/HPIM0430.jpg
>
> Sid Knox
>
> Velocity N199RS
> Starduster N666SK
> KR2 N24TC
> W7QJQ
>
> http://img35.exs.cx/img35/5182/HPIM0430.jpg
>
> "keepitrunning" > wrote in message >...
>> I was reading and saw a picture of a wing being tuft tested. I was
>> wondering, since I do not have a clue, how much difference the tape holding
>> the tufts would cause. In the picture it appears that 1/2 inch blue masking
>> tape was used and it was torn rather than cut. The tufts were spaced a
>> couple of inches apart and there were seven rows and eight columns. His
>> results were that the wing was not showing any separation. Just wondering
>> if there are accepted methods of doing this type of testing? How would you
>> determine where to test? Any discussion and comments would be appreciated.

Interesting to see the left side duct is pulling air forward and in around the center of the of the back lip of the
duct. Am I seeing that right? Are the two vortex generators causing it?

[sidk]

"Russell Kent" > wrote in message > 1. The photo seems to show submerged ducts, but they seem exceedingly narrow
> and improperly proportioned compared to my recollection of the drawings of
> the original submerged NACA ducts. How likely is it that the builder's
> ducts are versions of actual tested NACA ducts and not some random ducts
> that the builder preferred?

Kent, to the best of my knowledge, this duct mod is from the Velocity
factory and I believe all (most?) current Velocitys use it. The ducts
feed a pressure cowling (also factory designed/approved?). I have
added a photo of this to the free photo web hosting site.. see

http://img87.exs.cx/img87/4545/MVC-006F6.jpg

As you can see, the cowling is a very good fit.. no gaps for
leaks..sealed around edges with RTV Si.

There is more to the story... the right-hand duct is divided about
33/66 with the 33% going to the engine air induction via an air
filter. At full power take-off I see about 27.5 inches MAP (at 800 ft
msl and measuring/reading with a Vision Microsystems 800 display).
The left duct is divided about 33/66 with the 33 going to the oil
cooler (one of two coolers... the second is up front in the nose-gear
space).


> 2. Any air inlet, NACA or not, works best when the inlet is positioned in a
> (relatively) high air pressure region, and works poorly or even in reverse
> when placed in a (relatively) low air pressure region.
....
> Just speculating, the site just aft of the point of greatest fuselage height
> (where the ducts are now) seems like a local *low* pressure area.
....
> 3. Submerged NACA ducts work abysmally in areas of turbulent separation of
> flow. The photo seems to indicate that turbulent separation is occuring at
> the rear door seam.
....

> 4. The position of the existing ducts suggests that the engine uses
> downdraft cooling, i.e. the cooling air is introduced on the top side of the
> cylinders and pressures are used to force it out the bottom side of the
> cylinders. Downdraft cooling is prone to problems at low airflow velocities
> because of the tendency of heated air to rise. Low airflow velocities tend
> to coincide, unfortunately, with situations that need the best possible
> cooling, namely climbs (high power, low airspeed).

Yes, and the increased AOA during these conditions probably make the
situation even worse.

Sid

http://img87.exs.cx/img87/4545/MVC-006F6.jpg

[sidk]

Corky Scott > wrote in message >
> Sid, I hope that there are some other scoops somewhere besides the two
> I see on top of the airplane. From what I've read over the years if
> the two scoops I see are it for cooling, there are two really glaring
> problems. 1. Naca scoops are really marginal for engine cooling
> intakes, this is something that has been known for many years. 2.
> Naca scoops do not work when placed in a low pressure region of the
> fuselage. Your two scoops are on the downside of the rear of the
> fuselage and for sure are in a low pressure area.
>
> What works? Pitot type scoops placed in an area of positive pressure,
> or out in the free air stream ala P-51 Mustang.
>
> But if you have pitot type scoops on the belly of your airplane,
> nevermind.
>
> Corky Scott

No, there are no other cooling air inlets. The cooling air flows down
thru the pressure cowling, down thru the cylinders, and exits out the
back around the prop spinner.
This photo shows a rear, in-flight view. The small, dark object on
the bottom cowling is the left exhaust

http://img96.exs.cx/img96/5820/Velocityinflight.jpg

This Velocity was one of the earlier versions (early '90s). The
builder/previous owner told me that this was the third attempt...
The first (IRRC) was pitot type scoops on the bottom cowling. Then
pitot type scoops on the bottom of the strakes a few inches outboard
of the bottom cowling with internal ductwork (about 2 1/2 id) piping
the air into the engine compartment. Finally, apparently the Velocity
people came up with this current design and the plane was retrofitted
shortly before I bought it.

Sid

[Corky Scott]

On 29 Oct 2004 04:48:39 -0700, (sidk) wrote:

>Downdraft cooling is prone to problems at low airflow velocities
>> because of the tendency of heated air to rise. Low airflow velocities tend
>> to coincide, unfortunately, with situations that need the best possible
>> cooling, namely climbs (high power, low airspeed).
>
>Yes, and the increased AOA during these conditions probably make the
>situation even worse.
>
>Sid

This is where exhaust augmentation would improve things, if properly
done. Unfortunately, with a rear mounted engine, exhaust augmentation
is nearly impossible, simply not enough room.

Normally, exhaust augmentation has it's greatest effect exactly when
the engine needs it most: during takeoff and climb when airspeed is
low and power is high.

Corky Scott

[Corky Scott]

On 29 Oct 2004 05:17:03 -0700, (sidk) wrote:

>No, there are no other cooling air inlets. The cooling air flows down
>thru the pressure cowling, down thru the cylinders, and exits out the
>back around the prop spinner.
>This photo shows a rear, in-flight view. The small, dark object on
>the bottom cowling is the left exhaust
>
>http://img96.exs.cx/img96/5820/Velocityinflight.jpg
>
>This Velocity was one of the earlier versions (early '90s). The
>builder/previous owner told me that this was the third attempt...
>The first (IRRC) was pitot type scoops on the bottom cowling. Then
>pitot type scoops on the bottom of the strakes a few inches outboard
>of the bottom cowling with internal ductwork (about 2 1/2 id) piping
>the air into the engine compartment. Finally, apparently the Velocity
>people came up with this current design and the plane was retrofitted
>shortly before I bought it.
>
>Sid

Sid, I guess I'm stating the obvious then, the cooling system as
designed does not appear to flow enough air through the ductwork to
cool the engine properly.

You can probably improve the inflow by attaching scoops on top of the
Naca inlets. I'd recommend the scoops be standoffs, like the P-51
belly scoop so that you do not have turbulent boundary air flowing in
and disrupting the flow. You can even shape them to emulate the shape
of the Naca inlet where they attach to the opening. This should be an
easy thing to fabricate and attach for a test. Just tape them over
the inlets and fly. If you see the cooling improve, you're on the
right track.

Corky Scott

[Ernest Christley]

Corky Scott wrote:
> On 29 Oct 2004 05:17:03 -0700, (sidk) wrote:
>
>
>>No, there are no other cooling air inlets. The cooling air flows down
>>thru the pressure cowling, down thru the cylinders, and exits out the
>>back around the prop spinner.
>>This photo shows a rear, in-flight view. The small, dark object on
>>the bottom cowling is the left exhaust
>>
>>http://img96.exs.cx/img96/5820/Velocityinflight.jpg
>>
>>This Velocity was one of the earlier versions (early '90s). The
>>builder/previous owner told me that this was the third attempt...
>>The first (IRRC) was pitot type scoops on the bottom cowling. Then
>>pitot type scoops on the bottom of the strakes a few inches outboard
>>of the bottom cowling with internal ductwork (about 2 1/2 id) piping
>>the air into the engine compartment. Finally, apparently the Velocity
>>people came up with this current design and the plane was retrofitted
>>shortly before I bought it.
>>
>>Sid
>
>
> Sid, I guess I'm stating the obvious then, the cooling system as
> designed does not appear to flow enough air through the ductwork to
> cool the engine properly.
>
> You can probably improve the inflow by attaching scoops on top of the
> Naca inlets. I'd recommend the scoops be standoffs, like the P-51
> belly scoop so that you do not have turbulent boundary air flowing in
> and disrupting the flow. You can even shape them to emulate the shape
> of the Naca inlet where they attach to the opening. This should be an
> easy thing to fabricate and attach for a test. Just tape them over
> the inlets and fly. If you see the cooling improve, you're on the
> right track.
>
> Corky Scott
>
>

Sid, does the root airfoil of your propeller compare well with what the
factory has?

Air will flow with any pressure gradient. The factory design looks to
me like it is trying to accelerate the boundary layer along the back
half of the fuselage by having it 'sucked' through by the propeller. Of
course this will only work if the root of your propeller actually sucks.
Some blades are designed to no do anything at the root (Ivo is one, I
believe), and won't give you the pressure gradient you need.

--
http://www.ernest.isa-geek.org/
"This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."

[JDKAHN]

Generally the tufts are placed aft of the leading edge where there is no
laminar flow. Since the tape is in the turbulent boundry layer it has no
significant effect, any more than protruding rivet heads or skin laps do aft
of the laminar region. I don't think tufts on the leading edge are a good
idea. Putting them across a wing is mainly to observe the degree and
progression of flow separation at stall. Say if you wanted to install a set
of vortex generators on your leading edge and needed to find the most
beneficial location, you would tuft the wing behind them and film the tuft
behaviour at stalling AOA with the VGS at various chordwise locations to
find the optimum spot to place the VGs.

I'm an airline support techie for a regional aircraft maker and last summer
I put tufts on the flap of a regional jet that was mysteriously rolling with
flaps fully down and with seemingly symmetrical flight spoiler deployment.
The tufts revealed that when the flight spoilers were retracted to about 8
degrees one side had attained smooth flow in the slot between the spoiler
and the flap, but the other side was still transitioning from turbulent to
smooth because it was a tiny bit higher then the other (but within service
limits). This angle happened to correspond with the first detent on the
deployment lever (it's fly by wire) so the lever could be selected to this
position and all of a sudden the aircraft would start to roll. Move the
lever a tiny bit higher or lower and the roll would stop as symmetrical
spoiled or unspoiled lift was regained. I stuck them on pretty much by
eyeball using speed tape cut into little triangles.

John



"keepitrunning" > wrote in message
om...
>I was reading and saw a picture of a wing being tuft tested. I was
>wondering, since I do not have a clue, how much difference the tape holding
>the tufts would cause. In the picture it appears that 1/2 inch blue
>masking tape was used and it was torn rather than cut. The tufts were
>spaced a couple of inches apart and there were seven rows and eight
>columns. His results were that the wing was not showing any separation.
>Just wondering if there are accepted methods of doing this type of testing?
>How would you determine where to test? Any discussion and comments would
>be appreciated.
>

[sidk]

Corky Scott > wrote in message >

> You can probably improve the inflow by attaching scoops on top of the
> Naca inlets. I'd recommend the scoops be standoffs, like the P-51
> belly scoop so that you do not have turbulent boundary air flowing in
> and disrupting the flow. You can even shape them to emulate the shape
> of the Naca inlet where they attach to the opening. This should be an
> easy thing to fabricate and attach for a test. Just tape them over
> the inlets and fly. If you see the cooling improve, you're on the

Yes, that's a good plan except in my case I cannot "...Just tape them
over
the inlets and fly." because if one gets free it will go thru the
prop! However (as seen in the photo), there is a series of top
cowling screws that I can use to secure a temporary scoop.

Sid

[sidk]

Ernest Christley > wrote >

> Sid, does the root airfoil of your propeller compare well with what the
> factory has?

Don't think there is a "factory standard" (?) ... mine is an MT
(electric) constant-speed, "made for pushers".

>
> Air will flow with any pressure gradient. The factory design looks to
> me like it is trying to accelerate the boundary layer along the back
> half of the fuselage by having it 'sucked' through by the propeller. Of
> course this will only work if the root of your propeller actually sucks.
> Some blades are designed to no do anything at the root (Ivo is one, I
> believe), and won't give you the pressure gradient you need.

Yes, I have wondered about the possibility that maybe near the hub the
blades might be churning the air so much that there is some slight
back-pressure trying to push the cooling exit air back (forward) into
the cowling exit holes. I had taped some tufts just inside the exit
hole in the left side but none of the photos were able to see this
region.

At this point, I think a test by temporarily fastening some scoops to
the tops of the existing NACA ducts (as Corky posted above) is
relatively easy to do and may disclose a lot.

Sid

[Bob Korves]

WD-40 removes duct tape goo like magic...
-Bob Korves

"sidk" > wrote in message
om...
> Here is a link to a photo from last month's tuft-testing on my
> Velocity with hopes that some clue would appear as to why my engine
> cooling is worse than marginal. Tape was duct tape and some was on
> for several months (waiting for weather, photographer, digital camera,
> photoplane, etc...) and was a pain-in-the-butt to remove.
> For the test, the left (pilot) side NACA has two VGs, the right side
> none.
>
> http://img35.exs.cx/img35/5182/HPIM0430.jpg
>
> Sid Knox
>
> Velocity N199RS
> Starduster N666SK
> KR2 N24TC
> W7QJQ
>
> http://img35.exs.cx/img35/5182/HPIM0430.jpg
>
> "keepitrunning" > wrote in message
>...
> > I was reading and saw a picture of a wing being tuft tested. I was
> > wondering, since I do not have a clue, how much difference the tape
holding
> > the tufts would cause. In the picture it appears that 1/2 inch blue
masking
> > tape was used and it was torn rather than cut. The tufts were spaced a
> > couple of inches apart and there were seven rows and eight columns. His
> > results were that the wing was not showing any separation. Just
wondering
> > if there are accepted methods of doing this type of testing? How would
you
> > determine where to test? Any discussion and comments would be
appreciated.

[John]

Russell Kent wrote:

> "Sid Knox" > wrote:
>> At this point, I think a test by temporarily fastening some scoops to
>> the tops of the existing NACA ducts (as Corky posted above) is
>> relatively easy to do and may disclose a lot.
>
> Be certain that the temporary scoops are well attached. Losing a scoop in
> flight is almost certain to cause it to pass through the prop disc,
> turning an interesting experiment into a way-too-exciting flight.
>
> Russell Kent


Yeah, especially 200' up at the end of the runway!
John

[Russell Kent]

"Sid Knox" > wrote:
> At this point, I think a test by temporarily fastening some scoops to
> the tops of the existing NACA ducts (as Corky posted above) is
> relatively easy to do and may disclose a lot.

Be certain that the temporary scoops are well attached. Losing a scoop in
flight is almost certain to cause it to pass through the prop disc, turning
an interesting experiment into a way-too-exciting flight.

Russell Kent

[Russell Kent]

"Sid Knox" > wrote:
> Yes, that's a good plan except in my case I cannot "...Just tape them
> over the inlets and fly." because if one gets free it will go thru the
> prop! However (as seen in the photo), there is a series of top
> cowling screws that I can use to secure a temporary scoop.

Hmm. I guess I should've read the whole thread before I made my prevous
posting. It merely proves the "PMTA" rule: paranoid minds think alike. :-)

Russell Kent

[Paul Lee]

I don't know what engine size you have, but I have a Franklin 220hp
in my SQ2000 canard and the scoops do quite well in keeping the
engine cool.

http://www.abri.com/sq2000/finish21.jpg

(sidk) wrote in message >...
>.....
> Yes, that's a good plan except in my case I cannot "...Just tape them
> over
> the inlets and fly." because if one gets free it will go thru the
> prop! However (as seen in the photo), there is a series of top
> cowling screws that I can use to secure a temporary scoop.
>
> Sid