X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 09 Sep 2008 00:35:02 -0400 Message-ID: X-Original-Return-Path: Received: from web55705.mail.re3.yahoo.com ([216.252.110.36] verified) by logan.com (CommuniGate Pro SMTP 5.2.7) with SMTP id 3120498 for lml@lancaironline.net; Tue, 09 Sep 2008 00:07:29 -0400 Received: (qmail 15515 invoked by uid 60001); 9 Sep 2008 04:07:29 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:MIME-Version:Content-Type:Message-ID; b=RQHQR9nFJgzD294+7wUH+CBZagEhjMFLq77uG0Mi1dd7cgZ6FeZ2M6/wYepg3i/rsCuN9OamG0u1PjVt5reSMY/WRLZW/MwZexFYdplwJN09yeIiGGx8luxqTjPNpCym6B+xsQhPZziGR8u4TQGH7J6K716e/YC2eHuYXWKQ3xw=; X-YMail-OSG: v6a3WGMVM1lRnxOrID0I3XO7myPXdQ4oJKMKMBPhLWvNUTH5k7lheOfxGucAV8E4AZm0Z5kQs10Z5YZ0kyriSBMmFtPtzzRNpX8LNM.JTjjtHMJD0VYf97Hk70RLWql0l_KfjfuIryf32tOrnsg8 Received: from [71.31.132.122] by web55705.mail.re3.yahoo.com via HTTP; Mon, 08 Sep 2008 21:07:29 PDT X-Mailer: YahooMailRC/1096.28 YahooMailWebService/0.7.218.2 X-Original-Date: Mon, 8 Sep 2008 21:07:29 -0700 (PDT) From: J H Webb Subject: Re: [LML] Re: Lancair Accidents X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-2066773085-1220933249=:15420" X-Original-Message-ID: <827397.15420.qm@web55705.mail.re3.yahoo.com> --0-2066773085-1220933249=:15420 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable John,=0A=A0=0A=A0=A0=A0 Having done many thousands of stalls power on and o= ff in a great number of experimental aircraft, I have noticed one very impo= rtant item. That is as you approach the initial stall, first determine how = much down elevator response is available.=A0 If the rate of angle of attack= reduction decreases significantly as you approach the stall you have a pro= blem that you shouldn't explore further. Further be especially careful with= an aft CG location as stall behavior tends to get much worse as the CG is = moved aft as do general handling qualities.=0A=A0=A0=A0 If your airplane ma= intains a good angle of attack reduction up to the stall (as you get within= 5 knots of the stall you must be especially alert), then this being determ= ined, no matter how nasty the stall a quick reduction of angle of attack wi= ll allow very quick recovery from roll off and spin tendencies. If you are = prompt even in a bad airplane the roll will not exceed 45 degrees. There is= one additional thing that requires special attention and that is rudder ap= plication to produce good coordination. You must keep the ball within 1/2 b= all diameter in most high performance aircraft to maintain benign or reduce= the abrupt tendency to roll off to a spin. =0A=A0=A0=A0 In my previous lif= e, Aerodynamics would take wind tunnel information to determine the best lo= cation for flow strip positioning, then from there it was 'cut and try' so = I got lots and lots of stall practice. The object was to determine the best= location from several stand points. Some of the considerations were improv= ement in handling, least sensitive location for positioning errors, minimum= impact on stall speed,=A0length of flow strip, and size of strip. =0A=A0= =A0=A0 I have spent a lot of time and stalls (no wind tunnel information) d= etermining location, size and length to achieve good handling qualities. Wi= th good coordination and proper flow strips the Lancair can have very comfo= rtable stalls.=0A=A0=A0=A0Sorry to get so carried away but with a good basi= c design, stall handling problems can be relatively easily and inexpensivel= y improved. The Lancair is a very good basic design.=0A=A0=0AJack Webb=0AL3= 60, LIV=0AFormer Chief Engineering Test Pilot=0ABSAE=0A=0A=0A=0A----- Origi= nal Message ----=0AFrom: John Hafen =0ATo: lml@lancair= online.net=0ASent: Monday, September 8, 2008 3:31:12 PM=0ASubject: [LML] Re= : Lancair Accidents=0A=0AWhy would you want to practice stalling a plane su= ch as a IVP or IVPT that is quick to enter a spin and may or may not be rec= overable?=0A=0A=0AOn 9/7/08 3:08 PM, "Taylor, David" wrote:=0A=0A=0AJeff,=0A=A0=0AWe agree about 80%, =A0but I think you=92= re missing my point about pilot behavior and training and mindset.=A0 (I al= so need to be more careful about providing you with easy plays on =93dead s= erious=94 words.)=A0 Lancair pilots need more training =96 that=92s my poin= t too!!!!=A0 But I am saying that we need some concrete recommendations for= making this happen.=A0 We disagree about how to get the attention of the L= ancair population out there.=A0 I contend that treating them like 8 year ol= ds =A0is counter-productive.=A0 (they will tune you out.)=0A=0A=0A --0-2066773085-1220933249=:15420 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
=0A
John,
=0A 

=0A

    Ha= ving done many thousands of stalls power on and off in a great number of ex= perimental aircraft, I have noticed one very important item. That is as you= approach the initial stall, first determine how much down elevator respons= e is available.  If the rate of angle of attack reduction decreases si= gnificantly as you approach the stall you have a problem that you shouldn't= explore further. Further be especially careful with an aft CG location as = stall behavior tends to get much worse as the CG is moved aft as do general= handling qualities.

=0A

    If y= our airplane maintains a good angle of attack reduction up to the stall (as= you get within 5 knots of the stall you must be especially alert), then th= is being determined, no matter how nasty the stall a quick reduction of ang= le of attack will allow very quick recovery from roll off and spin tendenci= es. If you are prompt even in a bad airplane the roll will not exceed 45 de= grees. There is one additional thing that requires special attention and th= at is rudder application to produce good coordination. You must keep the ba= ll within 1/2 ball diameter in most high performance aircraft to maintain b= enign or reduce the abrupt tendency to roll off to a spin.

=0A    In my previous life, Aerodynamics would = take wind tunnel information to determine the best location for flow strip = positioning, then from there it was 'cut and try' so I got lots and lots of= stall practice. The object was to determine the best location from several= stand points. Some of the considerations were improvement in handling, lea= st sensitive location for positioning errors, minimum impact on stall speed= , length of flow strip, and size of strip.

=0A

    I have spent a lot of time and stalls (no wind tunn= el information) determining location, size and length to achieve good handl= ing qualities. With good coordination and proper flow strips the Lancair ca= n have very comfortable stalls.

=0A

    Sorry to get so carried away but with a good basic design, stall han= dling problems can be relatively easily and inexpensively improved. The Lan= cair is a very good basic design.

=0A
 
=0A
Jack Webb
=0A
L360, LIV
=0A
Former Chief Engineering = Test Pilot
=0A
BSAE
=0A

= =0A
----- Original Message ----
From: John Hafen <j.hafen@co= mcast.net>
To: lml@lancaironline.net
Sent: Monday, September 8, 20= 08 3:31:12 PM
Subject: [LML] Re: Lancair Accidents

Why wou= ld you want to practice stalling a plane such as a IVP or IVPT that is quic= k to enter a spin and may or may not be recoverable?


On 9/7/08 3= :08 PM, "Taylor, David" <dtaylor@crescentpark.com&= gt; wrote:

=0A
Jeff,
 
We agree about 80%,  but I think you=92re missing = my point about pilot behavior and training and mindset.  (I also need = to be more careful about providing you with easy plays on =93dead serious= =94 words.)  Lancair pilots need more training =96 that=92s my point t= oo!!!!  But I am saying that we need some concrete recommendations for= making this happen.  We disagree about how to get the attention of th= e Lancair population out there.  I contend that treating them like 8 y= ear olds  is counter-productive.  (they will tune you out.)
&n= bsp;

=0A=0A --0-2066773085-1220933249=:15420--