X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 14 Jan 2008 12:46:58 -0500 Message-ID: X-Original-Return-Path: Received: from mtao04.charter.net ([209.225.8.178] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with ESMTP id 2643417 for lml@lancaironline.net; Sun, 13 Jan 2008 12:36:52 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.225.8.178; envelope-from=troneill@charter.net Received: from aarprv06.charter.net ([10.20.200.76]) by mtao04.charter.net (InterMail vM.7.08.02.00 201-2186-121-20061213) with ESMTP id <20080113173604.MTHV10642.mtao04.charter.net@aarprv06.charter.net> for ; Sun, 13 Jan 2008 12:36:04 -0500 Received: from axs ([75.132.198.100]) by aarprv06.charter.net with SMTP id <20080113173603.YULM14098.aarprv06.charter.net@axs> for ; Sun, 13 Jan 2008 12:36:03 -0500 X-Original-Message-ID: <016901c8560a$c6df6510$6501a8c0@axs> From: "terrence o'neill" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Re: MKII tail vs original tail?? X-Original-Date: Sun, 13 Jan 2008 11:36:05 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0166_01C855D8.7BF0E1A0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 X-Chzlrs: 0 This is a multi-part message in MIME format. ------=_NextPart_000_0166_01C855D8.7BF0E1A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Excellent, Dom, and many thanks. Up-over here we have had many similar = observations by professional civil and military test pilots re the small = tail. Perhaps the first report was back in a KITPLANES August 1993 = article by pro test pilot Chuck Berthe. He mentiooned two things that = red-flagged a problem, for me. 1. The very light stick pitch force per = G (1.5 to 2 lb. stick force per g), and 2. the lack of after-stall = nose-drop or unstall pitching moment especially near the aft CG... so = that he had to push the stick forward after the stall, to reduce the AOA = and recover. This was apparently of such concern that Berthe did not = test 'full departure stalls'. Nevertheless, like many envious pilots = exposed to Lancairs, he enthusiastically concluded that "I would love to = have one." Me too; I bought one...kit # 11 ... and added anti-servo tabs to the = elevator, and a fix for the weak post-stall recovery pitch moment. Terrence L235/320 N211AL ----- Original Message -----=20 From: Dominic V Crain=20 Sent: Sunday, January 13, 2008 07:30 AM Subject: [LML] Re: MKII tail vs original tail?? (paraphrased original post) I have had email discussions with the test pilot who undertook some = of the test flying on the Lancair which resulted in the recommendation = to enlarge the tail. I quote from the email I received from one him on 20 September 2007: "...When the first example (a 320 I think?) was evaluated, it was = found to have 2 major design problems/defects. First the aft CG = condition was unrealistic (in excess of 30% MAC), and the horizontal = stabiliser was too small. Combined these resulted in neutral or = negative stick free longitudinal stability. Also manoeuvre stability = (stick force per G) was at best measured in ounces per G. Standard = comment from then owners was"I like it like that because it has fighter = like feel." These pilots had obviously never flown a fighter, at least = not one built since about 1920, which all have positive long stab, and = minimum stick forces of about 7 lb/G. =20 CASA insisted (under the good/bad old 101.28 rule) that stability be = improved. I think the aft CG limit was moved forward (not sure how = much) and bigger tails were required. The bigger tails (2 local REG 35 = solutions by Graham Swannel and Dave Simons) produced adequate = solutions, but the practicalities of keeping CG forward remained.=20 Very quickly the manufacturer of kit X came out with a bigger tail = (about 50% bigger!), and some advice on how to fix the CG problem. = Lancair eventually did the same.." Hopefully this will help, if not cause the usual broad-ranging hackles = raising. Cheers, Dom Crain VH-CZJ Melbourne Not Florida ------=_NextPart_000_0166_01C855D8.7BF0E1A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Excellent, Dom, and = many=20 thanks.  Up-over here we have had many similar observations by = professional=20 civil and military test pilots re the small tail.  = Perhaps the=20 first report was back in a KITPLANES August 1993 article by pro = test pilot=20 Chuck Berthe. He mentiooned two things that red-flagged a problem, for = me. =20 1. The very light stick pitch force per G (1.5 to 2 lb. stick force per = g), and=20 2. the lack of after-stall nose-drop or unstall pitching moment = especially near=20 the aft CG... so that he had to push the stick forward after the stall, = to=20 reduce the AOA and recover.  This was apparently of such = concern that=20 Berthe did not test 'full departure stalls'.  Nevertheless, like = many=20 envious pilots exposed to Lancairs, he enthusiastically concluded that = "I would=20 love to have one."
Me too; I bought = one...kit # 11=20 ... and added anti-servo tabs to the elevator, and a fix for the weak = post-stall=20 recovery pitch moment.
Terrence
L235/320 = N211AL
----- Original Message -----
From:=20 Dominic V=20 Crain
Sent: Sunday, January 13, 2008 = 07:30=20 AM
Subject: [LML] Re: MKII tail vs = original=20 tail??
(paraphrased = original=20 post)

 I have had = email=20 discussions with the test pilot who undertook some of the test flying = on the=20 Lancair which resulted in the recommendation to enlarge = the=20 tail.

 

I quote from the = email I=20 received from one him on 20 September 2007:

 

=93=85=85.When the=20 first example (a 320 I think?) was evaluated, it was found to have 2 = major=20 design problems/defects.  First the aft CG condition was = unrealistic (in=20 excess of 30% MAC), and the horizontal stabiliser was too small.  = Combined these resulted in neutral or negative stick free longitudinal = stability.  Also manoeuvre stability (stick force per G) was at = best=20 measured in ounces per G.  Standard comment from then owners = was"I like=20 it like that because it has fighter like feel."  These pilots had = obviously never flown a fighter, at least not one built since about = 1920,=20 which all have positive long stab, and minimum stick forces of about 7 = lb/G. 

 

CASA = insisted=20 (under the good/bad old 101.28 rule) that stability be improved.  = I think=20 the aft CG limit was moved forward (not sure how much) and bigger = tails were=20 required.  The bigger tails (2 local REG 35 solutions by Graham = Swannel=20 and Dave Simons) produced adequate solutions, but the practicalities = of=20 keeping CG forward remained. 

Very = quickly=20 the manufacturer of kit X came out with a bigger tail (about 50% = bigger!), and=20 some advice on how to fix the CG problem.  = Lancair = eventually=20 did the same=85=85=94

 

Hopefully this = will help, if=20 not cause the usual broad-ranging hackles raising.

 

Cheers,

Dom = Crain

VH-CZJ

Melbourne

Not = Florida

 

 

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