X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 30 Jun 2011 07:51:17 -0400 Message-ID: X-Original-Return-Path: Received: from mta11.charter.net ([216.33.127.80] verified) by logan.com (CommuniGate Pro SMTP 5.4.0) with ESMTP id 5037470 for lml@lancaironline.net; Wed, 29 Jun 2011 16:34:17 -0400 Received-SPF: pass receiver=logan.com; client-ip=216.33.127.80; envelope-from=troneill@charter.net Received: from imp10 ([10.20.200.15]) by mta11.charter.net (InterMail vM.7.09.02.04 201-2219-117-106-20090629) with ESMTP id <20110629203343.BBNB4013.mta11.charter.net@imp10> for ; Wed, 29 Jun 2011 16:33:43 -0400 Received: from [192.168.1.101] ([75.132.241.174]) by imp10 with smtp.charter.net id 1wZj1h0023mUFT705wZjEj; Wed, 29 Jun 2011 16:33:43 -0400 X-Authority-Analysis: v=1.1 cv=G6Q69DB3AUoJKS2BpLRaz8MQ2NORN7h5HRzrJMPOhRw= c=1 sm=1 a=Jpqhw6ujh_QA:10 a=yUnIBFQkZM0A:10 a=VxlS/kh5Y2KhHY/Xui1ATg==:17 a=SUyS9s6DnpLQfSu_PF4A:9 a=pILNOxqGKmIA:10 a=laKkv0ChnhS6abCyNckA:9 a=NeI2VV0YtpVoFuC3PisA:7 a=VxlS/kh5Y2KhHY/Xui1ATg==:117 From: Terrence O'Neill Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: multipart/alternative; boundary=Apple-Mail-4-359940908 Subject: Re: [LML] Re: Airplane needs to be "fixed," Stall Speeds, Wing Cuffs, Vortex ... X-Original-Date: Wed, 29 Jun 2011 15:33:42 -0500 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: <0C6B5CE9-ADE0-42E5-B392-E573D44295A2@charter.net> X-Mailer: Apple Mail (2.1084) --Apple-Mail-4-359940908 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 Angle saves. On Jun 29, 2011, at 2:49 PM, John Hafen wrote: > Speed Saves >=20 >=20 > On Jun 29, 2011, at 10:14 AM, Craig Berland. wrote: >=20 > Scott, > =20 > Excellent post. Just a few months ago I experienced a 30 kt wind = shear at 600 AGl going into John Wayne in Santa Ana, CA. Due to the = turbulence and =93on shore=94 wind I was quite fast on final and = obviously didn=92t stall however the three passengers were quite shaken. = In this situation, I=92m not aware of any instrumentation available to = GA aircraft that would have helped. John Wayne ATIS was shortly = thereafter modified to warn pilots of the wind shear near the end of the = runway. > =20 > Craig Berland > =20 > Terrence, > =20 > It doesn't always take the pilot to pull the wing beyond the critical = AOA - The air is not always smooth as in a stable fluid body - = turbulence, wind shear, slow flight over different heat radiating bodies = in the summer (green fields vs black dirt), crosswinds that tumble over = trees on a strip carved out of the woods or over nearby hangars, etc. = The margin above the stall AOA may disappear in a slow highly banked = turn or even on a straight in if the air is not compliant regardless of = the trim. =20 > =20 > I have been impressed with our 200-300 series reflexed laminar flow = wing - have you noticed a slow down (loss of laminar flow) in = turbulence? Is that just drag or is lift also affected? Does the = critical AOA change if the laminar flow is disturbed? Is this more = important when the wing is already at a high AOA when slow and is no = longer in reflex (flaps partially deployed)? Note that if the speed = changes, the trim is no longer correct. > =20 > I believe that the 300 series Lancairs are unstable at low speed high = AOA because the margin may be too narrow. It may not be the pilot = unintentionally pulling past the critical AOA, but an abrupt change in = the airflow that causes the angle to be exceeded. Even though the AOA = was calibrated in clean air, the calculated margin speed above stall by = formula (1.15 x stall) may not be enough for these high performance = wings. > =20 > Scott Krueger > =20 >=20 --Apple-Mail-4-359940908 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252 Angle = saves.

On Jun 29, 2011, at 2:49 PM, John Hafen = wrote:

Speed = Saves


On Jun 29, 2011, at 10:14 AM, = Craig Berland. wrote:

Scott, 
Craig = Berland
 
I have been impressed with our 200-300 series reflexed = laminar flow wing - have you noticed a slow down (loss of laminar = flow) in turbulence? Is that just drag or is lift also = affected?  Does the critical AOA change if the laminar flow is = disturbed?  Is this more important when the wing is already at a = high AOA when slow and is no longer in reflex (flaps partially = deployed)?  Note that if the speed changes, the trim is no longer = correct.
 
Scott Krueger