X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 18 May 2009 20:38:28 -0400 Message-ID: X-Original-Return-Path: Received: from imr-m07.mx.aol.com ([64.12.138.209] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3646254 for lml@lancaironline.net; Mon, 18 May 2009 18:21:26 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.138.209; envelope-from=Sky2high@aol.com Received: from imo-ma04.mx.aol.com (imo-ma04.mx.aol.com [64.12.78.139]) by imr-m07.mx.aol.com (v107.10) with ESMTP id RELAYIN1-24a11de083d; Mon, 18 May 2009 18:15:36 -0400 Received: from Sky2high@aol.com by imo-ma04.mx.aol.com (mail_out_v40_r1.5.) id q.cd3.55b2575c (14502) for ; Mon, 18 May 2009 18:15:30 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Mon, 18 May 2009 18:15:29 EDT Subject: Re: [LML] Re: Engine Out Practise X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1242684929" X-Mailer: AOL 9.1 sub 5006 X-Spam-Flag:NO X-AOL-IP: 64.12.78.139 -------------------------------1242684929 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Bill, Righto. Best glide = max endurance = minimum power for sustained level flight. For a 320/360, best glide is about 105 KIAS - a more accurate best glide can be found with a calibrated angle of attack indication for the flying weight and configuration. It doesn't take much power. But, if'n your engine quits, it doesn't much make no never-you-mind. There are three configurations of interest for airplanes with non-feathering constant speed props controlled by oil pressure. 1. Engine seized, prop flat (no pressure to keep some pitch in it). What is the best glide descent rate. Probably some medium amount of drag. 2. Engine rotating, cruise pitch (forgot to pull the prop to coarse pitch). What is the best glide descent rate. Probably horrible flat plat drag. 3. Engine rotating, coarse pitch held by oil pressure. What is the best glide descent rate. Least drag possible. Note that coarse pitch drag reduction is within a few percentage points of a feathered prop. The point being that a slicker-than-snot airplane's performance is greatly affected by any drag addition. This is unlike riveted, wing struted and welded down gear drag queens where the airframe drag is so great that any additional doesn't change performance by much. Check your prop manual for the pitch range limits (flat to coarse). Finally, thanks to Walter at GAMI, %HP = 100-((max RPM/100-RPM)*2.5+(Max MP-MP)*3.5) See what the RPM and MAP are at your best glide speed for a %HP figure. Grayhawk In a message dated 5/18/2009 1:48:13 P.M. Central Daylight Time, super_chipmunk@roadrunner.com writes: How many HP are required to keep a Lancair in the air? The wing loading is high so speed needs to be kept up but the airframes are very clean. A little bit of extra power may make a big difference in perceived results. **************A Good Credit Score is 700 or Above. See Yours in Just 2 Easy Steps! (http://pr.atwola.com/promoclk/100126575x1221322941x1201367178/aol?redir=http://www.freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=115&bcd =Mayfooter51809NO115) -------------------------------1242684929 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Bill,

Righto. Best glide =3D max endurance =3D minimum power for sust= ained level flight. For a 320/360, best glide is about 105 KIAS - a= more accurate best glide can be found with a calibrated angle of attack indication for the flying weight and configuration.

It doesn't take much power.

But, if'n your engine quits, it doesn't much make no never-you-mind.<= /DIV>

There are three configurations of interest for airplanes with non-feathering constant speed props controlled by oil pressure.<= /DIV>

1. Engine seized, prop flat (no pressure to keep some pitch in it).&n= bsp; What is the best glide descent rate. Probably some medium amount of= drag.

2. Engine rotating, cruise pitch (forgot to pull the prop to coarse= pitch). What is the best glide descent rate. Probably hor= rible flat plat drag.

3. Engine rotating, coarse pitch held by oil pressure. What is the best glide descent rate. Least drag possible. Note th= at coarse pitch drag reduction is within a few percentage points of a feather= ed prop.

The point being that a slicker-than-snot airplane's performance = is greatly affected by any drag addition. This is unlike riveted, wing= struted and welded down gear drag queens where the airframe drag is= so great that any additional doesn't change performance by much. Check= your prop manual for the pitch range limits (flat to coarse).

Finally, thanks to Walter at GAMI,

%HP =3D 100-((max RPM/100-RPM)*2.5+(Max MP-MP)*3.5)

See what the RPM and MAP are at your best glide speed for a %HP figure.

Grayhawk

In a message dated 5/18/2009 1:48:13 P.M. Central Daylight Time, super_chipmunk@roadrunner.com writes:

How many HP are required to keep a Lancair in the air? The wing loading is
hi= gh so speed needs to be kept up but the airframes are very clean. A little bit of extra power may make a big difference in perceived results.

A Good= Credit Score is 700 or Above. See= Yours in Just 2 Easy Steps!

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