X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 27 Oct 2011 11:08:04 -0400 Message-ID: X-Original-Return-Path: Received: from imr-ma02.mx.aol.com ([64.12.206.40] verified) by logan.com (CommuniGate Pro SMTP 5.4.2) with ESMTP id 5174622 for lml@lancaironline.net; Thu, 27 Oct 2011 10:23:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.206.40; envelope-from=Sky2high@aol.com Received: from mtaomg-mb05.r1000.mx.aol.com (mtaomg-mb05.r1000.mx.aol.com [172.29.41.76]) by imr-ma02.mx.aol.com (8.14.1/8.14.1) with ESMTP id p9REN83a025627 for ; Thu, 27 Oct 2011 10:23:08 -0400 Received: from core-mtc002c.r1000.mail.aol.com (core-mtc002.r1000.mail.aol.com [172.29.235.5]) by mtaomg-mb05.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 11C23E00008C for ; Thu, 27 Oct 2011 10:23:08 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Thu, 27 Oct 2011 10:23:07 -0400 (EDT) Subject: Re: [LML] Re: Fw: Updated SUMMARY OF LANCAIR ACCIDENTS IN NTSB DATABASE X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_c6b9.72affc53.3bdac34b_boundary" X-Mailer: AOL 9.6 sub 168 X-Originating-IP: [24.1.9.48] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:476362848:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d294c4ea9694c1dbb --part1_c6b9.72affc53.3bdac34b_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Terrence, Yes, but the statement is too simple and is only true in smooth air under a constant load. The flying wing AOA (angle between wing and air flow) is not always under control of the pilot. Operating at an air speed near the stall AOA allows the wing to stall if the air is not smooth such as perturbations from turbulence (wake, wind shear, gusts, etc.) Pilot control is a component when operating near the stall AOA and loading up the wing without increasing the air flow that increases the AOA leading to a wing stall (i.e. low speed base to final turn where the bank angle is increased and the stick is pulled to line up with the runway on final). I wonder if there are differences if the wing exhibits a great deal of laminar flow (like Lancairs). In chop I find that I am slowed a bit. Is that because the laminar flow is disturbed? My AOA indicator also bounces around a bit. (A "bit" is a term of art.) My solution, when near the airport, is to keep a greater air speed margin above stall AOAs, use an arc turn from downwind to final (allows continuous adjustment for runway line up) and a higher glide slope angle to maintain plenty of kinetic energy for, uh, unexpected air burbles near the ground. The only time I want to be stalled (cease flying) is within inches of the runway. Scott Krueger In a message dated 10/26/2011 3:45:22 P.M. Central Daylight Time, troneill@charter.net writes: Just a brief note: Counting only the sixty-three 235 and 320 accidents, eleven of the crashes (17.5%) resulted from the pilot pulling his wing past it's stall angle of attack, for whatever reason. This is defining "cause" as the last effective act of a pilot prior to him losing control. Most of these AOA accidents occurred at too low an altitude to permit possible recovery. It would be interesting to find out how many of these aircraft had AOAs installed. Generally, an airplane's wing flies (hands off) at the (unstalled) trim angle, no matter what the attitude. Pilot input is required to bring a wing to an AOA above stall. Discussion is invited. Terrence L235/320 N211AL On Oct 25, 2011, at 8:00 PM, William Rumburg wrote: > Lee Metcalfe took time and effort to update the Lancair Accident Summary he created several years ago. I'm submitting it for him since he is no longer active on the LML. It's for all of our benefit...read and heed > > Bill Rumburg > N403WR (Sonic bOOm) > -- > For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html --part1_c6b9.72affc53.3bdac34b_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Terrence,
 
Yes, but the statement is too simple and is only true in smo= oth=20 air under a constant load.  The flying wing AOA (angle between wing an= d air=20 flow) is not always under control of the pilot.  Operating at an = air=20 speed near the stall AOA allows the wing to stall if the air is not sm= ooth=20 such as perturbations from turbulence (wake, wind shear, gusts, etc.)&= nbsp;=20
 
Pilot control is a component when operating near the stall AOA and loa= ding=20 up the wing without increasing the air flow that increases the AOA lea= ding=20 to a wing stall (i.e. low speed base to final turn where the bank angl= e is=20 increased and the stick is pulled to line up with the runway on=20 final).
 
I wonder if there are differences if the wing exhibits a great de= al of=20 laminar flow (like Lancairs).  In chop I find that I am slowed a bit.&= nbsp;=20 Is that because the laminar flow is disturbed?  My AOA indicator = also=20 bounces around a bit.  (A "bit" is a term of art.) 
 
My solution, when near the airport, is to keep a greater air=20 speed margin above stall AOAs, use an arc turn from downwind to f= inal=20 (allows continuous adjustment for runway line up) and a higher glide s= lope=20 angle to maintain plenty of kinetic energy for, uh, unexpected air burbles = near=20 the ground.  The only time I want to be stalled (cease flying) is= =20 within inches of the runway.
 
Scott Krueger
 
In a message dated 10/26/2011 3:45:22 P.M. Central Daylight Time,=20 troneill@charter.net writes:
= Just a=20 brief note:
Counting only the sixty-three  235 and 320 accidents,= =20 eleven of the crashes (17.5%) resulted from the pilot pulling his wing pa= st=20 it's stall angle of attack, for whatever reason. 
This is defini= ng=20 "cause" as the last effective act of a pilot prior to him losing control.= Most=20 of these AOA accidents occurred at too low an altitude to permit possible= =20 recovery.
It would be interesting to find out how many of these aircra= ft=20 had AOAs installed.
Generally, an airplane's wing flies (hands off) at= the=20 (unstalled) trim angle, no matter what the attitude. Pilot input is requi= red=20 to bring a wing to an AOA above stall.
Discussion is=20 invited.
Terrence  L235/320 N211AL


On Oct 25, 2011, at= 8:00=20 PM, William Rumburg wrote:

> Lee Metcalfe took time and effort = to=20 update the Lancair Accident Summary he created several years ago. I'm=20 submitting it for him since he is no longer active on the LML. It's for a= ll of=20 our benefit...read and heed
>
> Bill Rumburg
> N403WR= =20 (Sonic bOOm)

> --
> For archives and unsub=20 http://mail.lancaironline.net:81/lists/lml/List.html



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