Return-Path: Received: from [65.54.169.67] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2b1) with ESMTP id 3151712 for flyrotary@lancaironline.net; Wed, 07 Apr 2004 20:58:41 -0400 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 7 Apr 2004 17:58:41 -0700 Received: from 199.183.223.30 by bay3-dav37.adinternal.hotmail.com with DAV; Thu, 08 Apr 2004 00:58:41 +0000 X-Originating-IP: [199.183.223.30] X-Originating-Email: [kerrjb@msn.com] X-Sender: kerrjb@msn.com From: "WALTER KERR" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: idle speeds (prop stopped flight) Date: Wed, 7 Apr 2004 08:58:44 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0034_01C41C7E.88544E60" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 8.5 X-MimeOLE: Produced By MSN MimeOLE V8.50.0017.1202 Seal-Send-Time: Wed, 7 Apr 2004 08:58:45 -0400 Message-ID: X-OriginalArrivalTime: 08 Apr 2004 00:58:41.0284 (UTC) FILETIME=[A246CC40:01C41D04] This is a multi-part message in MIME format. ------=_NextPart_000_0034_01C41C7E.88544E60 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Charlie,=20 I'm not even sure at what ground idle speed was when I flew the test. I = realized one day that I was using a lot of brake to keep the airplane = down to a brisk taxi on asphalt. Turns out my cable restraining nut had = backed off and the plane was idling at 900 rpm. My landings sure got = better again when I set it back to 750 rpm. Bernie ----- Original Message -----=20 From: Charlie & Tupper England=20 To: Rotary motors in aircraft=20 Sent: Tuesday, April 06, 2004 9:12 PM Subject: [FlyRotary] Re: idle speeds (prop stopped flight) Hi Bernie, What was your idle speed (plane stationary on the ground) on the Lyc?=20 Would the results have been the same if you had set the idle speed to=20 850-900 rpm & then flown the same test idling & stopped prop? WALTER KERR wrote: > Hi Charlie, > =20 > I had a cruise prop (80 inch pitch) sensenich metal prop on the 6A.=20 > When I was doing engine off glide testing, some thought I would do=20 > better with engine stopped rather than turning. Really had to slow = way=20 > down to get prop to stop. Could not measure the difference in glide=20 > engine stopped or windmilling. Really had to go fast, over a hundred = > to get it going again! > =20 > Bernie Kerr, painting the 9A waiting to get rotary back from Bruce T = > at SnF > > ----- Original Message ----- > From: Charlie & Tupper England > To: Rotary motors in aircraft = > Sent: Sunday, April 04, 2004 11:06 PM > Subject: [FlyRotary] Re: idle speeds > > I agree with Jim about this. I've had similar problems with a = Lyc > powered RV-4. Anything over about 800 prop rpm caused a lot of > float. > I'd be interested to see the calculations on whether a really = highly > pitched cruise prop is producing thrust at 800-850 rpm & = 60-70mph. I > think that it's at least safe to say that the airflow isn't > driving the > prop disc & producing drag like a climb or c/s prop. > > I wonder what engine-stopped glide angle would look like = compared > to the > angle we get used to while being pulled along by the engine on = final. > This could be a significant safety issue if there's an engine = failure > when we have become acclimated to unknowingly carrying power > (thrust) on > final. > > Charlie > > > > Jim Sower wrote: > > > <... I need to get the idle speed way down ...> > > You sure do. I've regaled you several times about my EZ with = an > O-235 > > idling at 800-900 rpm that could NEVER be slowed down enough = to > land - > > floated 1000' or more down every damned runway I encountered.=20 > Landed > > fine when I set the idle down to 500-600 rpm. Ran rough as a > cob at > > that speed on the ground (which is why it had been set so = high), > but I > > could advance it to 800 for ground ops, and go to the idle = stop on > > final. With all your power, I would emphatically recommend = that > you > > back the idle down till it will just barely idle on the = ground.=20 > You > > can always taxi above the idle stop, but you can never land > below it.=20 > > I would also strongly recommend a shutdown switch (injectors?=20 > pumps?) > > near the throttle quadrant for convenient shutdown on final. = A > > guarded switch (guarded ON) would satisfy safety = considerations, > and > > be convenient enough that you could shut down nearly as easily = as > > pulling the mixture. > > > > That way, you have all the bases covered ... Jim S. > >=20 > > > > John Slade wrote: > > > >> Last week we had some discussion on idle speeds, and I think = the > >> consensus > >> was to keep it around 2000 or a little under. Just for = information > >> for other > >> canard pusher people, I think 2000 is going to be a real > problem for > >> me. At > >> the current 1850 setting with the big 3 66/84 prop I have on = she's > >> pushing > >> hard against the brakes. I think I could taxi the length of = the > >> runway at > >> idle and be doing 30/40 kts at the end. On a short (3400) > runway the > >> only > >> way to stop might be kill the engine once on the ground, or > even on > >> short > >> final. So I need to get the idle speed way down. > >> John Slade (more power than I know what to do with) > >> > >> >> Homepage: http://www.flyrotary.com/ > >> >> Archive: = http://lancaironline.net/lists/flyrotary/List.html > >> > > -- > > Jim Sower ... Destiny's Plaything > > Crossville, TN; Chapter 5 > > Long-EZ N83RT, Velocity N4095T > >=20 > > > > > > >> Homepage: http://www.flyrotary.com/ > >> Archive: = http://lancaironline.net/lists/flyrotary/List.html > >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_0034_01C41C7E.88544E60 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Charlie,
 
I'm not even sure at what ground idle speed was when I flew the = test. I=20 realized one day that I was using a lot of brake to keep the airplane = down to a=20 brisk taxi on asphalt. Turns out my cable restraining nut had backed off = and the=20 plane was idling at 900 rpm. My landings sure got better again when I = set it=20 back to 750 rpm.
 
Bernie
----- Original Message -----
From: Charlie & Tupper England =
To: Rotary motors in = aircraft
Sent: Tuesday, April 06, 2004 = 9:12=20 PM
Subject: [FlyRotary] Re: idle = speeds=20 (prop stopped flight)

Hi Bernie,

What was your idle speed (plane = stationary on=20 the ground) on the Lyc?
Would the results have been the same if = you had=20 set the idle speed to
850-900 rpm & then flown the same test = idling=20 & stopped prop?



WALTER KERR wrote:

> Hi=20 Charlie,
> 
> I had a cruise prop (80 inch pitch) = sensenich=20 metal prop on the 6A.
> When I was doing engine off glide = testing, some=20 thought I would do
> better with engine stopped rather than = turning.=20 Really had to slow way
> down to get prop to stop. Could not = measure=20 the difference in glide
> engine stopped or windmilling. Really = had to=20 go fast, over a hundred
> to get it going again!
>  =
>=20 Bernie Kerr, painting the 9A waiting to get rotary back from Bruce T =
>=20 at SnF
>
>     ----- Original Message=20 -----
>     From: Charlie & Tupper = England=20 <mailto:cengland@netdoor.com><= BR>>    =20 To: Rotary motors in aircraft <mailto:flyrotary@lancaironlin= e.net>
>    =20 Sent: Sunday, April 04, 2004 11:06 PM
>     = Subject:=20 [FlyRotary] Re: idle speeds
>
>     I = agree=20 with Jim about this. I've had similar problems with a=20 Lyc
>     powered  RV-4. Anything over = about=20 800 prop rpm caused a lot of
>    =20 float.
>     I'd be interested to see the=20 calculations on whether a really = highly
>    =20 pitched cruise prop is producing thrust at 800-850 rpm &  = 60-70mph.=20 I
>     think that it's at least safe to say = that=20 the airflow isn't
>     driving=20 the
>     prop disc & producing drag = like a=20 climb or c/s prop.
>
>     I wonder = what=20 engine-stopped glide angle would look like=20 compared
>     to=20 the
>     angle we get used to while being = pulled=20 along by the engine on final.
>     This = could be a=20 significant safety issue if there's an engine=20 failure
>     when we have become acclimated = to=20 unknowingly carrying power
>     (thrust)=20 on
>    =20 final.
>
>    =20 Charlie
>
>
>
>     Jim = Sower=20 wrote:
>
>     > <... I need to = get the=20 idle speed way down ...>
>     > You = sure=20 do.  I've regaled you several times about my EZ with=20 an
>     = O-235
>     >=20 idling at 800-900 rpm that could NEVER be slowed down enough=20 to
>     land = -
>     >=20 floated 1000' or more down every damned runway I encountered.=20
>     = Landed
>     >=20 fine when I set the idle down to 500-600 rpm.  Ran rough as=20 a
>     cob = at
>     >=20 that speed on the ground (which is why it had been set so=20 high),
>     but = I
>    =20 > could advance it to 800 for ground ops, and go to the idle stop=20 on
>     > final.  With all your = power, I=20 would emphatically recommend that
>    =20 you
>     > back the idle down till it = will just=20 barely idle on the ground.
>    =20 You
>     > can always taxi above the = idle stop,=20 but you can never land
>     below it.=20
>     > I would also strongly recommend = a=20 shutdown switch (injectors?
>    =20 pumps?)
>     > near the throttle = quadrant for=20 convenient shutdown on final.  A
>     = >=20 guarded switch (guarded ON) would satisfy safety=20 considerations,
>    =20 and
>     > be convenient enough that you = could=20 shut down nearly as easily as
>     > = pulling the=20 mixture.
>     = >
>    =20 > That way, you have all the bases covered ... Jim=20 S.
>     > =
>    =20 >
>     > John Slade=20 wrote:
>     = >
>    =20 >> Last week we had some discussion on idle speeds, and I think=20 the
>     >>=20 consensus
>     >> was to keep it = around 2000=20 or a little under. Just for = information
>    =20 >> for other
>     >> canard = pusher=20 people, I think 2000 is going to be a = real
>    =20 problem for
>     >> me.=20 At
>     >> the current 1850 setting = with the=20 big 3 66/84 prop I have on she's
>     = >>=20 pushing
>     >> hard against the = brakes. I=20 think I could taxi the length of the
>     = >>=20 runway at
>     >> idle and be doing = 30/40 kts=20 at the end. On a short (3400)
>     runway=20 the
>     >>=20 only
>     >> way to stop might be = kill the=20 engine once on the ground, or
>     even=20 on
>     >>=20 short
>     >> final. So I need to get = the=20 idle speed way down.
>     >> John = Slade (more=20 power than I know what to do with)
>    =20 >>
>     >> >> =20 Homepage:  http://www.flyrotary.com/
>&= nbsp;   =20 >> >>  Archive:   http://lancai= ronline.net/lists/flyrotary/List.html
>    = =20 >>
>     >=20 --
>     > Jim Sower ... Destiny's=20 Plaything
>     > Crossville, TN; Chapter = 5
>     > Long-EZ N83RT, Velocity=20 N4095T
>     > =
>    =20 >
>
>
>
>     = >> =20 Homepage:  http://www.flyrotary.com/
>&= nbsp;   =20 >>  Archive:   http://lancai= ronline.net/lists/flyrotary/List.html
>



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