X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 08 Jan 2013 08:34:47 -0500 Message-ID: X-Original-Return-Path: Received: from nk11p08mm-asmtp002.mac.com ([17.158.58.247] verified) by logan.com (CommuniGate Pro SMTP 6.0.1) with ESMTP id 6000352 for lml@lancaironline.net; Tue, 08 Jan 2013 06:34:25 -0500 Received-SPF: pass receiver=logan.com; client-ip=17.158.58.247; envelope-from=gw5@me.com MIME-version: 1.0 Content-type: multipart/alternative; boundary="Boundary_(ID_aVHm2MuyNiWtO71/dAD0VQ)" Received: from [10.55.209.100] (216-147-135-217.globalsat.net [216.147.135.217]) by nk11p08mm-asmtp002.mac.com (Oracle Communications Messaging Server 7u4-26.01(7.0.4.26.0) 64bit (built Jul 13 2012)) with ESMTPSA id <0MGB00AOY1G5I610@nk11p08mm-asmtp002.mac.com> for lml@lancaironline.net; Tue, 08 Jan 2013 11:33:49 +0000 (GMT) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.9.8327,1.0.431,0.0.0000 definitions=2013-01-08_01:2013-01-08,2013-01-07,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 suspectscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=6.0.2-1203120001 definitions=main-1301080058 Subject: Re: [LML] Re: Stalls & Spins References: From: George Wehrung X-Mailer: iPhone Mail (10A523) In-reply-to: X-Original-Message-id: X-Original-Date: Tue, 08 Jan 2013 16:03:39 +0430 X-Original-To: Lancair Mailing List --Boundary_(ID_aVHm2MuyNiWtO71/dAD0VQ) Content-type: text/plain; charset=utf-8 Content-transfer-encoding: quoted-printable John,=20 I would be interested in watching some of the videos on the ES in particular= if not the other airframes. Are they posted on the Internet by chance, doub= tful but I thought I'd ask. Sent from my iPhone On Jan 8, 2013, at 15:50, John Smith wrote: > =46rom my perspective, the key phrase is spin resistance. >=20 > Having researched the NASA material and having also seen the Lancair video= s of actual flight testing, rightly or wrongly, I installed the wing cuffs t= o the Legacy on the basis that they seemed to offer the opportunity to make i= t harder to get into trouble, but accepting that if pushed too far into a sp= in, then the aircraft may or may not be recoverable. So, if one accepts the v= iew of many which is that "as was", the aircraft was not spin recoverable, t= here would only appear to be upside from installing the cuffs. The flaw is, o= f course, that if indeed the Legacy is spin recoverable without wing cuffs, t= hen the addition of the wing cuffs may preclude spin recovery! >=20 > Unless someone goes to the trouble of spin testing the Legacy, or any othe= r type fitted with cuffs, one will never know whether spin recoveries are po= ssible under what flight and loading circumstances and, of course, with or w= ithout wing cuffs. >=20 > Meanwhile, per my prior post on this, all I can say is that the albeit ver= y limited flight testing (straight and level, and continuous 30deg AoB turns= ) in my Legacy fitted with the cuffs shows that there is plenty of warning o= f the impending stall =E2=80=93 stall strips give the first "gentle" warning= ", followed by the more severe intermittent "shuddering" as the centre secti= on drops in and out of the stall (whilst the outboard sections are still fly= ing). >=20 > I'm happy to talk to anyone if they are interested to talk about this more= =E2=80=A6. numbers below, but please note time is UTC + 8!! >=20 >=20 > Regards, >=20 > John >=20 >=20 > John N G Smith > Tel / fax: +61-8-9385-8891 > Mobile: +61-409-372-975 > Email: john@jjts.net.au >=20 >=20 > From: > Reply-To: Lancair Mailing List > Date: Tuesday, 8 January 2013 2:25 AM > To: > Subject: [LML] Re: Stalls & Spins >=20 >=20 >=20 > Posted for "Peter Field" : >=20 > Dear Lancair Drivers: >=20 >=20 >=20 > I've been following the discussion on stalls and spins and I want to add > some additional factual information purely for your personal consumption a= nd > reflection. Attached are excerpts from 10 different 1980-90 NASA flight > test final reports on a series of GA airplanes in which NASA evaluated the= > use of cuffs on leading edges to improve the behavior of the test airplane= > approaching the stall. For various reasons the cuffs improved lateral > control entering the stall, but had the adverse effect of destabilizing th= e > aircraft once a fully developed spin was achieved. Essentially, stall > behavior was improved at the sacrifice of spin recovery. Cuffs on wing > leading edges are an add on design fix, the more elegant solution is > "washout," where the wing is twisted so the outer portions of the wing > always operate at a lower angle of attack. >=20 >=20 >=20 > To my knowledge, Lancair has never subjected any of their aircraft to a > fully developed spin matrix complete with appropriate instrumentation and a= > spin recovery chute. There is no FAA requirement for them to do so - it's= > an Experimental Category airplane. Early on they may have lightly touched= > on such testing; but I have never seen any documentation on a fully > completed spin matrix, which would involve at least 160 spins at various > cg's and lateral loadings. In my opinion, it would be highly risky to foo= l > around much beyond the stall in any Lancair - there is no documentation th= at > indicates any of these airplanes can always be recovered from a one turn > incipient phase spin or any fully developed spin. Being good at spin > recovery isn't so much a matter of how skillful a pilot you are, it's a > matter of how many spins you've experienced in airplanes known to be > recoverable. Being familiar with the stall characteristics of your own > airplane should be a matter of personal preference. =20 >=20 >=20 >=20 > Best regards,=20 >=20 > Pete Field (LNC2) >=20 > USNTPS graduate & spin recovery instructor >=20 >=20 >=20 > -- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.= html --Boundary_(ID_aVHm2MuyNiWtO71/dAD0VQ) Content-type: text/html; charset=utf-8 Content-transfer-encoding: quoted-printable
John, 

I= would be interested in watching some of the videos on the ES in particular i= f not the other airframes. Are they posted on the Internet by chance, doubtf= ul but I thought I'd ask.




Se= nt from my iPhone

On Jan 8, 2013, at 15:50, John Smith <john@jjts.net.au> wrote:

=46rom my perspective, the ke= y phrase is spin resistance.

Having research= ed the NASA material and having also seen the Lancair videos of actual fligh= t testing, rightly or wrongly, I installed the wing cuffs to the Legacy on t= he basis that they seemed to offer the opportunity to make it harder to get i= nto trouble, but accepting that if pushed too far into a spin, then the airc= raft may or may not be recoverable. So, if one accepts the view of ma= ny which is that "as was", the aircraft was not spin recoverable, there woul= d only appear to be upside from installing the cuffs. The flaw is, of course= , that if indeed the Legacy is spin recoverable without wing cuffs, then the= addition of the wing cuffs may preclude spin recovery!

Unless someone goes to the trouble of spin testing the Lega= cy, or any other type fitted with cuffs, one will never know whether spin re= coveries are possible under what flight and loading circumstances and, of co= urse, with or without wing cuffs.

Meanwhile, per my= prior post on this, all I can say is that the albeit very limited flight te= sting (straight and level, and continuous 30deg AoB turns) in my Legacy fitt= ed with the cuffs shows that there is plenty of warning of the impending sta= ll =E2=80=93 stall strips give the first "gentle" warning", followed by the m= ore severe intermittent "shuddering" as the centre section drops in and out o= f the stall (whilst the outboard sections are still flying).

<= /div>
I'm happy to talk to anyone if they are interested to talk about t= his more=E2=80=A6. numbers below, but please note time is UTC + 8!!


Regards,

John
John N G Smith
Tel / fax:    +61-8-9385-8891
Mobile:      +61-409-372-975
Email:         john@jjts.net.au

From: <marv@lancair.net>
Reply-To: Lancair Mailing List <lml@lancaironline.net>
Date: Tuesday, 8 January 2013 2:25 AM
To: <lml>
Subject: <= /span> [LML] Re: Stalls & Spins



Posted for "Peter Field" <= pfield.avn@gmail.com>:
Dear Lancair Drivers:



I've been following the discussion o= n stalls and spins and I want to add
some additional factual information purely for your personal consumption and
reflection. &n= bsp;Attached are excerpts from 10 different 1980-90 NASA flight
test final reports on a series of GA airplanes in which NASA evaluated the
us= e of cuffs on leading edges to improve the behavior of the test airplane
approaching the stall.  For various reasons the cuffs= improved lateral
control entering the stall, but had the adverse effect of destabilizing the
aircraft once a fully developed spin was ach= ieved.  Essentially, stall
behavior was improved at the sacrifice of spin recovery.  Cuffs on wing
leading edges are a= n add on design fix, the more elegant solution is
"washout," where the wing is twisted so the outer portions of the wing
always operate at a lo= wer angle of attack.



To my knowledge, Lancair has never subjected any of their aircraft to a
fully developed spin matrix complet= e with appropriate instrumentation and a
spin recovery chute.  There is no FAA requirement for them to do so - it's
a= n Experimental Category airplane.  Early on they may have lightly touched
on such testing; but I have never seen any documentation= on a fully
completed spin matrix, which would involve at least 160 spins at various
cg's and lateral loadings.  In my opinion, it= would be highly risky to fool
around much beyond the stall in any Lancair - there is no documentation that
indicates any of these airplane= s can always be recovered from a one turn
incipient phase spin or any fully developed spin.  Being good at spin
recovery isn't so mu= ch a matter of how skillful a pilot you are, it's a
matter of how many spins you've experienced in airplanes known to be
recoverable. &nbs= p;Being familiar with the stall characteristics of your own
airplane should be a matter of personal preference.  



Be= st regards,

Pete Field (LNC2)

USNTPS graduate & spin recovery instructor



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