Return-Path: Received: from [65.54.169.56] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 574135 for flyrotary@lancaironline.net; Mon, 20 Dec 2004 11:57:38 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.169.56; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Mon, 20 Dec 2004 08:57:08 -0800 Message-ID: Received: from 65.54.98.161 by BAY3-DAV26.phx.gbl with DAV; Mon, 20 Dec 2004 16:56:38 +0000 X-Originating-IP: [65.54.98.161] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" Subject: Fw: [FlyRotary] Re: George Graham glide update Date: Mon, 20 Dec 2004 11:51:48 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0127_01C4E68A.4962BEE0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0009.2900 Seal-Send-Time: Mon, 20 Dec 2004 11:51:48 -0500 X-OriginalArrivalTime: 20 Dec 2004 16:57:08.0505 (UTC) FILETIME=[F1005890:01C4E6B4] This is a multi-part message in MIME format. ------=_NextPart_000_0127_01C4E68A.4962BEE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Gyro (auto rotation) is a different case. As impossible as it may seem, = the air is going through the rotor blades OPPOSITE to the rotation you = would expect them to turn with no power applied. In my 8 years of = flying gyros I always used to look out at the blades and wonder what = kept them turning. It happens to be the same aerodynamic forces which = makes a plane glide forward with no engine. If you think about the fact = that the wings have a positive angle of attack even with no power, the = plane SHOULD go backwards. In any case, this is completely different than a wind milling prop. Tracy ----- Original Message -----=20 From: Tom=20 I'm glad I only went as far as saying they might differ. Gyrocopters = have free-wheeling blades, they would probably descend a 'bit' quicker if = the blades stopped rotating. =20 There really are posts here which have more useful info. I've spent a = few hours today and a couple yesterday going thru them and capturing and = organizing info. Break-in oils, oil-thermostats, fuel-injector stuff, = soft-mounting stock Mazda oil coolers, MMO, A/F indicators, intake manifold lengths = and configurations, ignition coil wire types, ... I'm actually feeling = good about being able to have a good installation that'll work reliably despite = my lack of any background. Something I'd like to find is 'how to remove powder = coating from a motor'. Gold was a bad choice, I'd have less other parts to = paint if the motor were silver and blue. I'll probably simply repaint over = the gold. =20 =20 Tom --- Bob White > wrote: > I suspect they would be different. To hazard a guess, a free = spinning > prop is doing less work than a prop turning a motor, so it should > provide less drag. But a fixed pitch prop in either condition would = want > to turn somewhere in the range of speed you would be gliding at. A = prop > at flat pitch would need to speed up to a very high rpm to match the > forward speed of the plane. If the prop can't keep up with the = forward > speed of the plane, it will effectively be pushing backward creating > extra drag. At least that's my armchair analysis. =20 >=20 > Bob White >=20 > On Sun, 19 Dec 2004 18:10:25 -0800 (PST) > Tom > wrote: >=20 > > I wonder if a free-spinning prop on a broken tranny would not have = the > > same drag as a spinning prop which is turning the motor? I'd be > > inclined to say they would differ.=20 > >=20 > > Tom > >=20 > >=20 > > --- Bob White > wrote: > >=20 > > > Somenone else recently reported a spinning prop having = negligable > > > effect on engine out glide. (Dave Leonard maybe?). I'm = thinking > > > that the biggest effect occurs with a C/S prop that goes to flat > > > pitch when it looses oil pressure. I think twins often use > > > feathering props for that reason. > > >=20 > > > Bob White > > >=20 > > > On Sun, 19 Dec 2004 15:41:53 -0500 > > > "Tracy Crook" > wrote: > > >=20 > > > He glided about 20 miles from an altitude of only 5000 ft with = the > > > prop > > > freewheeling! I've heard several times that a freewheeling = prop > > > (no engine drag on it) would generate lots of drag. Another = sacred > > > cow shot down : ) > > > >=20 > > > > Tracy=20 > > >=20 > > > --=20 > > > http://www.bob-white.com > > > N93BD - Rotary Powered BD-4 (soon) > > >=20 > > > >> Homepage: = http://www.flyrotary.com/ > > > >> Archive: = http://lancaironline.net/lists/flyrotary/List.html > > >=20 > >=20 > >=20 > >=20 > >=20 > > __________________________________=20 > > Do you Yahoo!?=20 > > Yahoo! Mail - Helps protect you from nasty viruses.=20 > > = http://promotions.yahoo.com/new_mail > >=20 > > >> Homepage: = http://www.flyrotary.com/ > > >> Archive: = http://lancaironline.net/lists/flyrotary/List.html > >=20 > >=20 >=20 >=20 > --=20 > http://www.bob-white.com > N93BD - Rotary Powered BD-4 (soon) >=20 > >> Homepage: http://www.flyrotary.com/ > >> Archive: = http://lancaironline.net/lists/flyrotary/List.html >=20 __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around=20 http://mail.yahoo.com=20 >> Homepage: http://www.flyrotary.com/ >> Archive: = http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_0127_01C4E68A.4962BEE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 

Gyro (auto rotation) is a different case.  As impossible as it = may=20 seem, the air is going through the rotor blades OPPOSITE to the rotation = you=20 would expect them to turn with no power applied.   In my 8 = years of=20 flying gyros I always used to look out at the blades and wonder what = kept them=20 turning.   It happens to be the same aerodynamic forces which = makes a=20 plane glide forward with no engine.  If you think about the fact = that the=20 wings have a positive angle of attack even with no power, the plane = SHOULD go=20 backwards.
 
In any case, this is completely different than a wind milling = prop.
 
Tracy
----- Original Message -----
From: Tom

I'm glad I only went as far as saying they might=20 differ.   Gyrocopters have
free-wheeling blades, they = would=20 probably descend a 'bit' quicker if the blades
stopped=20 rotating.   

There really are posts here which = have=20 more useful info.  I've spent a few
hours today and a couple = yesterday=20 going thru them and capturing and organizing
info.   = Break-in=20 oils, oil-thermostats, fuel-injector stuff, soft-mounting
stock = Mazda oil=20 coolers, MMO, A/F indicators, intake manifold lengths = and
configurations,=20 ignition coil wire types, ... I'm actually feeling good about
being = able to=20 have a good installation that'll work reliably despite my lack = of
any=20 background.    Something I'd like to find is 'how to = remove=20 powder coating
from a motor'.  Gold was a bad choice, I'd have = less=20 other parts to paint if
the motor were silver and blue.   = I'll=20 probably simply repaint over the gold. =20
      

Tom


--- = Bob White=20 <bob@bob-white.com> = wrote:

> I=20 suspect they would be different.  To hazard a guess, a free=20 spinning
> prop is doing less work than a prop turning a motor, = so it=20 should
> provide less drag. But a fixed pitch prop in either = condition=20 would want
> to turn somewhere in the range of speed you would = be=20 gliding at.  A prop
> at flat pitch would need to speed up = to a=20 very high rpm to match the
> forward speed of the plane.  = If the=20 prop can't keep up with the forward
> speed of the plane, it = will=20 effectively be pushing backward creating
> extra drag.  At = least=20 that's my armchair analysis. 
>
> Bob White
> =
> On Sun, 19 Dec 2004 18:10:25 -0800 (PST)
> Tom <tomtugan@yahoo.com> = wrote:
>=20
> > I wonder if a free-spinning prop on a broken tranny = would not=20 have the
> > same drag as a spinning prop which is turning = the=20 motor?    I'd be
> > inclined to say they = would=20 differ.
> >
> > Tom
> >
> > =
>=20 > --- Bob White <bob@bob-white.com> = wrote:
> >=20
> > > Somenone else recently reported a spinning prop = having=20 negligable
> > > effect on engine out glide.  (Dave = Leonard=20 maybe?).  I'm thinking
> > > that the biggest effect = occurs=20 with a C/S prop that goes to flat
> > > pitch when it = looses oil=20 pressure.  I think twins often use
> > > feathering = props for=20 that reason.
> > >
> > > Bob White
> = > >=20
> > > On Sun, 19 Dec 2004 15:41:53 -0500
> > = > "Tracy=20 Crook" <lors01@msn.com> wrote:
> = > >=20
> > >  He glided about 20 miles from an altitude of = only=20 5000 ft with the
> > >  prop
> > >=20 freewheeling!   I've heard several times that a freewheeling = prop
> > > (no engine drag on it) would generate lots of=20 drag.  Another sacred
> > > cow shot down : )
> = >=20 > >
> > > > Tracy
> > >
> = > >=20 --
> > > http://www.bob-white.com
> = > >=20 N93BD - Rotary Powered BD-4 (soon)
> > >
> > = >=20 >>  Homepage:  http://www.flyrotary.com/
> = >=20 > >>  Archive:   http://lancai= ronline.net/lists/flyrotary/List.html
>=20 > >
> >
> >
> >
> > =
>=20 > __________________________________
> > Do you Yahoo!? =
>=20 > Yahoo! Mail - Helps protect you from nasty viruses.
> > = http://promotions.yahoo.com= /new_mail
>=20 >
> > >>  Homepage:  http://www.flyrotary.com/
> = >=20 >>  Archive:   http://lancai= ronline.net/lists/flyrotary/List.html
>=20 >
> >
>
>
> --
> http://www.bob-white.com
> = N93BD -=20 Rotary Powered BD-4 (soon)
>
> >>  = Homepage:  http://www.flyrotary.com/
> = >>  Archive:   http://lancai= ronline.net/lists/flyrotary/List.html
>=20


__________________________________________________
Do = You=20 Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam = protection=20 around
http://mail.yahoo.com =

>> =20 Homepage:  http://www.flyrotary.com/
>&= gt; =20 Archive:   http://lancai= ronline.net/lists/flyrotary/List.html
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