[rebel-builders] Re: slow flight pitch

Garry · Post by **Garry** » Sun Feb 19, 2012 4:47 pm

I just did the stall tests on FOKM yesterday on floats with votex
generators on the wings only. I did not actually measure the angle but
would estimate that with full flaps at about 2100 rpm, the deck angle
would be between 20 and 25 degrees. That is an absurd angle and I was
not too interested in checking it to the limits. I suspect that with
full power it would probably exceed 30 degrees and may not stall at all.
I also think that putting vg's on the tail surfaces would flatten it out
a bit too. You can't see anything forward in this attitude, the ASI goes
to essentially meaningless values and it is quite stable in the air. On
wheels the angle would be even more exaggerated.

Garry

Ron Shannon wrote:

And a related variation: how about max. angle at full power? (This
will _really_ vary. <g>)

On Sat, Jul 19, 2008 at 11:28 AM, Ron Shannon <rshannon@cruzcom.com> wrote:

Query for those who are flying: what is the approximate maximum angle
above horizontal at which your Rebel will fly in powered slow flight?
I realize this may vary due to numerous factors, but would like to get
a handle on the general range.

Ron
254R
http://n254mr.com

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Ron Shannon · Post by **Ron Shannon** » Sun Feb 19, 2012 4:47 pm

Thanks, Garry. In addition to slow flight angles, in the context of
[extreme] fuel flow testing I'm pondering what angle simulates a full
power takeoff stall or mush, as the case may be. So ASI accuracy
doesn't matter, just angle.

Would you mind taking a digital level or sextant along next time? :-)

On Sat, Jul 19, 2008 at 3:39 PM, Garry <wright.garry30@gmail.com> wrote:

I just did the stall tests on FOKM yesterday on floats with votex
generators on the wings only. I did not actually measure the angle but
would estimate that with full flaps at about 2100 rpm, the deck angle
would be between 20 and 25 degrees. That is an absurd angle and I was
not too interested in checking it to the limits. I suspect that with
full power it would probably exceed 30 degrees and may not stall at all.
I also think that putting vg's on the tail surfaces would flatten it out
a bit too. You can't see anything forward in this attitude, the ASI goes
to essentially meaningless values and it is quite stable in the air. On
wheels the angle would be even more exaggerated.

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Ken · Post by **Ken** » Sun Feb 19, 2012 4:47 pm

Hi Ron

If you can raise the mainwheels about a foot higher than the tailwheel
I think you will find that you'd never have occasion to pull the nose
that high.
Ken

Ron Shannon wrote:

Thanks, Garry. In addition to slow flight angles, in the context of
[extreme] fuel flow testing I'm pondering what angle simulates a full
power takeoff stall or mush, as the case may be. So ASI accuracy
doesn't matter, just angle.

Would you mind taking a digital level or sextant along next time? :-)

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Garry · Post by **Garry** » Sun Feb 19, 2012 4:47 pm

I agree with Ken on that for sure. Its a bit disconcerting to see the
nose bound for Pluto even when you know whats going on.

Garry

Ken wrote:

Hi Ron

If you can raise the mainwheels about a foot higher than the tailwheel
I think you will find that you'd never have occasion to pull the nose
that high.
Ken

Ron Shannon wrote:

Thanks, Garry. In addition to slow flight angles, in the context of
[extreme] fuel flow testing I'm pondering what angle simulates a full
power takeoff stall or mush, as the case may be. So ASI accuracy
doesn't matter, just angle.

Would you mind taking a digital level or sextant along next time? :-)

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Ron Shannon · Post by **Ron Shannon** » Sun Feb 19, 2012 4:47 pm

Thanks, Ken. Sounds like you had a great Ramble. Wish I could have
joined this year.

I can't easily lower my tailwheel to check the ground attitude angle
at the moment (supposedly, real building is happening in level
attitude) but as I recall ground attitude is about 11 deg. pitch up.
As you suggest, a 1" rise over 17" run (approximating the wheelbase)
looks like an additional ~ 3.35 deg. Rough numbers, but it seems like
the angle approaching a full power stall/mush would be more than 14-15
deg. I'd expect power off stall to be in that region, but the angle
approaching full power stall/mush would be quite a bit higher, no?

Some banana brain may try to hang on the prop sometime (certainly not
_this_ banana brain <g>) and I'd like to test whether gravity feed
fuel starvation may be one of the results.

Ron

On Sat, Jul 19, 2008 at 4:23 PM, Ken <klehman@albedo.net> wrote:

Hi Ron

If you can raise the mainwheels about a foot higher than the tailwheel
I think you will find that you'd never have occasion to pull the nose
that high.
Ken

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Ron Shannon · Post by **Ron Shannon** » Sun Feb 19, 2012 4:47 pm

Gosh, after our adventure last summer, I could have sworn FOKM _and_
her owner were aerobatic. :-)

On Sat, Jul 19, 2008 at 5:29 PM, Garry <wright.garry30@gmail.com> wrote:

I agree with Ken on that for sure. Its a bit disconcerting to see the
nose bound for Pluto even when you know whats going on.

Garry

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Joe Ronco · Post by **Joe Ronco** » Sun Feb 19, 2012 4:47 pm

RON: If you only have a 17" wheelbase I think that you have some serious
work to do.

:) Joe

See you in Oshkosh.

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com] On Behalf Of Ron
Shannon
Sent: Saturday, July 19, 2008 6:34 PM
To: rebel-builders@dcsol.com
Subject: Re: [rebel-builders] Re: slow flight pitch

Thanks, Ken. Sounds like you had a great Ramble. Wish I could have
joined this year.

I can't easily lower my tailwheel to check the ground attitude angle
at the moment (supposedly, real building is happening in level
attitude) but as I recall ground attitude is about 11 deg. pitch up.
As you suggest, a 1" rise over 17" run (approximating the wheelbase)
looks like an additional ~ 3.35 deg. Rough numbers, but it seems like
the angle approaching a full power stall/mush would be more than 14-15
deg. I'd expect power off stall to be in that region, but the angle
approaching full power stall/mush would be quite a bit higher, no?

Some banana brain may try to hang on the prop sometime (certainly not
_this_ banana brain <g>) and I'd like to test whether gravity feed
fuel starvation may be one of the results.

Ron

On Sat, Jul 19, 2008 at 4:23 PM, Ken <klehman@albedo.net> wrote:

Hi Ron

If you can raise the mainwheels about a foot higher than the tailwheel
I think you will find that you'd never have occasion to pull the nose
that high.
Ken

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Ron Shannon · Post by **Ron Shannon** » Sun Feb 19, 2012 4:47 pm

ROTFL -- Actually, fixing a 17" wheelbase mistake might be easier
than fixing some of the other bonehead things I've done. :-)

[Oshkosh, aye, full steam ahead.]

On Sat, Jul 19, 2008 at 5:48 PM, Joe Ronco <joe@halzel.com> wrote:

RON: If you only have a 17" wheelbase I think that you have some serious
work to do.

:) Joe

See you in Oshkosh.

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Drew Dalgleish · Post by **Drew Dalgleish** » Sun Feb 19, 2012 4:47 pm

Hi Ron I was out tonight and I didn't try any slow flight but my best angle
of climb seems to be around 45 degrees. That's solo with almost full fuel
and it was hot 25C I was only getting 1600fpm on a cold day I can get well
over 2000.

At 11:33 AM 7/19/2008 -0700, you wrote:

And a related variation: how about max. angle at full power? (This
will _really_ vary. <g>)

On Sat, Jul 19, 2008 at 11:28 AM, Ron Shannon <rshannon@cruzcom.com> wrote:
Query for those who are flying: what is the approximate maximum angle
above horizontal at which your Rebel will fly in powered slow flight?
I realize this may vary due to numerous factors, but would like to get
a handle on the general range.

Ron
254R
http://n254mr.com

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Drew

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Ron Shannon · Post by **Ron Shannon** » Sun Feb 19, 2012 4:47 pm

Thanks for the info, Drew. Wow, 45 deg. is really climbing! Not to mention
2000 FPM on a cold day. What's your engine again? To test fuel flow at 45
deg. up from level attitude, I'd have to build quite a scaffold to raise and
secure the mains -- so the whole plane wouldn't fall onto the tailwheel.
:-)

Ron

On Sun, Jul 20, 2008 at 7:40 PM, Drew Dalgleish <drewjan@cabletv.on.ca>
wrote:

Hi Ron I was out tonight and I didn't try any slow flight but my best angle
of climb seems to be around 45 degrees. That's solo with almost full fuel
and it was hot 25C I was only getting 1600fpm on a cold day I can get well
over 2000.

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Drew Dalgleish · Post by **Drew Dalgleish** » Sun Feb 19, 2012 4:47 pm

Hi Ron my engine is an 0-320 clone by ECI electronic ignition and a very
fine pitched prince prop. It's a great prop when I'm on floats but too fine
on wheels.

At 08:38 PM 7/20/2008 -0700, you wrote:

Thanks for the info, Drew. Wow, 45 deg. is really climbing! Not to mention
2000 FPM on a cold day. What's your engine again? To test fuel flow at 45
deg. up from level attitude, I'd have to build quite a scaffold to raise and
secure the mains -- so the whole plane wouldn't fall onto the tailwheel.
:-)

Ron

Drew

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