X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 04 Sep 2005 13:47:38 -0400 Message-ID: X-Original-Return-Path: Received: from wproxy.gmail.com ([64.233.184.193] verified) by logan.com (CommuniGate Pro SMTP 5.0c2) with ESMTP id 710642 for lml@lancaironline.net; Sat, 03 Sep 2005 21:11:47 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.233.184.193; envelope-from=limadelta@gmail.com Received: by wproxy.gmail.com with SMTP id 37so718511wra for ; Sat, 03 Sep 2005 18:11:03 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=NfoRtQ/mwstqGuwvHs8FvJdP3/DLdyyQaVq9vQGzwTzTMsJyneY8WSkF9nJJjrBSlvQBUsO0fOqJRn573CpbgFNXtLXjOlWMsLnDbeOcjpNWtJITTUk8iRMz7uEgEOdR+uFxOpun1TLwfIemXHZkLr3IzGW2pe1QXKH6aQ6Xpg0= Received: by 10.54.48.62 with SMTP id v62mr3356785wrv; Sat, 03 Sep 2005 18:11:03 -0700 (PDT) Received: by 10.54.46.71 with HTTP; Sat, 3 Sep 2005 18:11:03 -0700 (PDT) X-Original-Message-ID: X-Original-Date: Sat, 3 Sep 2005 21:11:03 -0400 From: Dan O'Brien X-Original-To: Lancair Mailing List Subject: Re: [LML] Re: airspeed on final In-Reply-To: Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_7790_5620104.1125796263124" References: ------=_Part_7790_5620104.1125796263124 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Two things I've noted about this issue. First, the early brochure for the E= S=20 listed dirty stall as 58 mph. That's right, MPH (factory guys, please don't= =20 take this the wrong way). That's about 50 knots. Would someone please tell= =20 me the conditions required to produce a stall in the ES of 50 knots? How=20 about the 210 HP engine, one person on board, and an hour of fuel. Maybe=20 that would do it. I raise this because the "book" stall in the brochures has always been a=20 little optimistic. The current number, 65 mph, is about 57 kts. From what= =20 I've seen on the lists, people get more like 60-62 kts (about 70 mph) in=20 their testing. Note that 1.3 times 62 (not 1.3 times 57) is about 80 kts,= =20 which is the minimum approach speed recommended in the ES manual that=20 Carsten put together a few years ago. (That manual says do 80-85).=20 Second, I wonder if it possible that the rule of thumb of 1.3 times the=20 dirty stall is more applicable to relatively idiot-proof wings like those= =20 found on C172 & 182s than it is for Lancairs? I'm no aerodynamicist, but I= =20 know from reading about wings that the stall of the wing on the ES and IV i= s=20 sharper than the stall on the Cessna. It always seemed to me that the=20 difference in the wings could justify a greater safety margin. (It seems=20 there is no free lunch, except on the Columbia which, like Roger Federer, i= s=20 practially spin proof AND has a slick wing).=20 Anyone know if business jets, which also have slick wings, use more than 1.3times the dirty stall? Just curious. On 8/31/05, MikeEasley@aol.com wrote: >=20 > I was reading about all these high speed approaches and did some looking= .=20 > Lancair advertises the Legacy dirty stall at 67 mph. Convert to knots, 1.= 3x VSO and you get a 76 knot approach speed. The ES dirty stall is 65 mph,= =20 > for a 74 knot final approach speed. > I fly my ES at 80 down final without too much float, more that I got wit= h=20 > my Mooney though. Why are the Legacy guys zooming down final? > Mike Easley > Still in Paint > ------=_Part_7790_5620104.1125796263124 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Two things I've noted about this issue.  First, the early brochure for the ES listed dirty stall as 58 mph.  That's right, MPH (factory guys, please don't take this the wrong way).  That's about 50 knots.  Would someone please tell me the conditions required to produce a stall in the ES of 50 knots?  How about the 210 HP engine, one person on board, and an hour of fuel.  Maybe that would do it.

I raise this because the "book" stall in the brochures has always= been a little optimistic.  The current number, 65 mph, is about 57 kts.  From what I've seen on the lists, people get more like 60-62 kts (about 70 mph) in their testing. Note that 1.3 times 62 (not 1.3 times 57) is about 80 kts, which is the minimum approach speed recommended in the ES manual that Carsten put together a few years ago.  (That manual says do 80-85). 

Second, I wonder if it possible that the rule of thumb of 1.3 times the dirty stall is more applicable to relatively idiot-proof wings like those found on C172 & 182s than it is for Lancairs?  I'm no aerodynamicist, but I know from reading about wings that the stall of the wing on the ES and IV is sharper than the stall on the Cessna.  It always seemed to me that the difference in the wings could justify a greater safety margin.  (It seems there is no free lunch, except on the Columbia which, like Roger Federer, is practially spin proof AND has a slick wing).

Anyone know if business jets, which also have slick wings, use more than 1.= 3 times the dirty stall?  Just curious.


On 8/31/05, MikeEasley@aol.com <MikeEasley@aol.com> wrote:
I was reading about all these high speed approaches and did some=20 looking.  Lancair advertises the Legacy dirty stall at 67 mph. = =20 Convert to knots, 1.3 x VSO and you get a 76 knot approach speed.  The= ES=20 dirty stall is 65 mph, for a 74 knot final approach speed.
 
I fly my ES at 80 down final without too much float, more that I got w= ith=20 my Mooney though.  Why are the Legacy guys zooming down final?
 
Mike Easley
Still in Paint

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