X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 08 Sep 2008 15:30:14 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m19.mx.aol.com ([64.12.137.11] verified) by logan.com (CommuniGate Pro SMTP 5.2.7) with ESMTP id 3118766 for lml@lancaironline.net; Sun, 07 Sep 2008 19:03:27 -0400 Received: from Sky2high@aol.com by imo-m19.mx.aol.com (mail_out_v38_r10.8.) id q.cc1.41879bcd (48576) for ; Sun, 7 Sep 2008 19:03:20 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Sun, 7 Sep 2008 19:04:39 EDT Subject: Re: [LML] McCauley Prop Governor Unfeathering Accumulator X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1220828679" X-Mailer: Unknown sub 34 X-Spam-Flag:NO -------------------------------1220828679 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Uh, just so those that do not have full feathering props think that they must have one, consider this. My Hartzell has a maximum coarse pitch setting - I think it is about 40 degrees (I don't have the prop manual handy). Aerodynamics for Naval Aviators figure 2.19 has chart of propeller blade angle vs change in parasitic drag area. There is a significant drop in drag area from 12* (flat pitch) to 40* (coarse pitch) and a very small drop if the blade was further pitched at 60*. There is no further drop from 60* to 90*. I think we non feathering birds-of-a-feather need some pitch to keep the prop rotating in order to keep the oil pressure high enough to maintain the 40* (duh!). At approximately zero thrust and best glide: cruise pitch = 1500 fpm, coarse pitch = 400-500 fpm. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Pilot not TSO'd, Certificated score only > 70%. In a message dated 9/7/2008 5:10:02 P.M. Central Daylight Time, liegner@embarqmail.com writes: ........... **************Psssst...Have you heard the news? There's a new fashion blog, plus the latest fall trends and hair styles at StyleList.com. (http://www.stylelist.com/trends?ncid=aolsty00050000000014) -------------------------------1220828679 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Uh, just so those that do not have full feathering props think that the= y=20 must have one, consider this. My Hartzell has a maximum coarse pitch=20 setting - I think it is about 40 degrees (I don't have the prop manual=20 handy). Aerodynamics for Naval Aviators figure 2.19 has chart of prope= ller=20 blade angle vs change in parasitic drag area. There is a significant d= rop=20 in drag area from 12* (flat pitch) to 40* (coarse pitch) and a very small dr= op=20 if the blade was further pitched at 60*. There is no further drop= =20 from 60* to 90*. I think we non feathering birds-of-a-feather nee= d=20 some pitch to keep the prop rotating in order to keep the oil= =20 pressure high enough to maintain the 40* (duh!).

At approximately zero thrust and best glide: cruise pitch =3D 1500 fpm,= =20 coarse pitch =3D 400-500 fpm.

Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)

Pil= ot=20 not TSO'd, Certificated score only > 70%.

In a message dated 9/7/2008 5:10:02 P.M. Central Daylight Time,=20 liegner@embarqmail.com writes:

<= FONT=20 face=3D"Times New Roman" size=3D1>...........=20

Psssst...Have you heard the news? There's a n= ew fashion blog, plus the latest fall trends and hair styles at StyleList.co= m. -------------------------------1220828679--