X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from omr-m09.mx.aol.com ([64.12.143.82] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 6865367 for lml@lancaironline.net; Fri, 09 May 2014 08:43:50 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.143.82; envelope-from=Sky2high@aol.com Received: from mtaomg-aaa01.mx.aol.com (mtaomg-aaa01.mx.aol.com [172.27.1.227]) by omr-m09.mx.aol.com (Outbound Mail Relay) with ESMTP id 317C6702371BA for ; Fri, 9 May 2014 08:43:16 -0400 (EDT) Received: from core-mlc003b.r1000.mail.aol.com (core-mlc003.r1000.mail.aol.com [172.29.188.209]) by mtaomg-aaa01.mx.aol.com (OMAG/Core Interface) with ESMTP id EA90938000082 for ; Fri, 9 May 2014 08:43:15 -0400 (EDT) From: Sky2high@aol.com Full-name: Sky2high Message-ID: <2c7c7.3f22d988.409e2763@aol.com> Date: Fri, 9 May 2014 08:43:15 -0400 (EDT) Subject: Re: [LML] Re: [LML][LNC2] Fast taxi testing - found the problem To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_2c7c7.3f22d988.409e2763_boundary" X-Mailer: AOL 9.6 sub 168 X-Originating-IP: [24.14.166.87] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1399639396; bh=AWRujS4U9wMA6j8B9qauvcTC5KKSKjcTQBfceaLi4qk=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=PUnNivqGrkSilADs/u8DqJZzE7uRBl4/IsmSeIwqRo3xdi57qgtoPYkKnY3VYAspS xWeAxd9Ohm3so1LfiKbPZ1jZWwEBCVrJ/RBsavT8dVlCLO/TZJQiuh3LPMQKUm4z/h S7/101WYNPysAgDXZmjFopdwtJt6W9V1OzbOhMUg= x-aol-sid: 3039ac1b01e3536ccd637979 --part1_2c7c7.3f22d988.409e2763_boundary Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable OK then - =20 A Lancair 320 with the 70" Hartzell prop has strong left turning tendencies= =20 - P-factor, torque, etc. The small vertical stab and rudder do not take = =20 control until some speed is achieved - on mine is was at about 40 KIAS and,= =20 as you noted, you see some control at about 30. The moving plane wants to= =20 weather vane in crosswinds, especially those from the left. On the ground= =20 quartering head winds have an effect on the upwind down flap whilst the le= e=20 flap is partially blocked by the fuselage - more left turning if the wind= =20 is from the left. =20 =20 If power is applied rapidly at the start of a takeoff run or fast taxi, the= =20 left turning tendency is very strong. It is best to apply power slowly = =20 until rudder control is there.=20 =20 If all the left forcing factors are present, their effect is additive. =20 Right brake tapping is useful.=20 =20 Grayhawk =20 PS If you are on the left side of a crowned taxiway or runway - well, =20 there's another factor. =20 PPS I loved right crosswinds for takeoffs and landings. =20 PPPS - If one main gear leg is vertical and the other is not, there is an = =20 effect.=20 =20 =20 In a message dated 5/9/2014 7:05:47 A.M. Central Daylight Time, =20 snopercod@comporium.net writes: In response to Greyhawk: Toe out is an unstable condition. The jury seems to still be out on that subject. I can find experienced=20 pilots who swear by either toe-in or toe-out. Since my toe-out condition i= s=20 only a fraction of a degree, I'm just going to leave it alone for now. If = it=20 becomes a problem later on, I'll fix the 0.6=BA tire with a shim at the ba= se=20 of the axle. The 0.2=BA isn't worth messing with. I want to get this plane= =20 flying sometime before I die (grin). 2. If these are the original Matco wheels, note that the pin bearing=20 races are aligned conically. Thus, one needs to make sure the axle nut (w= ith=20 washer on the inside shoulder and under the nut) is snugged tight enough t= o=20 keep the bearings properly supporting the wheel. Loose wheels will destro= y=20 the bearings (nose wheel included). The usual rule is that they are=20 properly tight if the wheel will not make a complete revolution when hand = spun=20 whilst on jacks. Remember to make sure the bearings are packed with=20 appropriate grease. Yes, I have the original Matco wheels and the original Rosenhan brakes.=20 I've adjusted the axle nuts so the tire will spin 1-1/4 turns by hand. The= =20 bearings are snug that way, yet it leaves a little room for thermal =20 expansion. We saw what happened when I turned the axle nut one flat beyond = that=20 point and it wasn't pretty. Yes, the bearings are well packed with =20 high-temperature grease. I checked that a few hours ago. 3. The brake pad float bushings should allow the pad mounts to move freely= =20 (SS not rusty steel) and properly positioned so that relaxing brake pedal= =20 pressure causes no pressure on the pad to the rotor. Check. 4. Remember that when steering - one toe presses (or just taps) the=20 inside-the-turn pedal whilst the other foot holds the rudder pedal steady = so that=20 you are not slamming the rudder over. That's the way I do it, but after all these years of using only brakes to= =20 steer the plane, I find I have to retrain my mind to stay off the brakes a= t=20 over 30 KTs and let the rudder do the steering. Thanks for the sage comments. --part1_2c7c7.3f22d988.409e2763_boundary Content-Type: text/html; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable
OK then -
 
A Lancair 320 with the 70" Hartzell prop has strong left turning tende= ncies=20 - P-factor, torque, etc.  The small vertical stab and rudder do not ta= ke=20 control until some speed is achieved - on mine is was at about 40 KIAS= and,=20 as you noted, you see some control at about 30.  The moving = plane=20 wants to weather vane in crosswinds, especially those from the left. On the= =20 ground quartering head winds have an effect on the upwind down flap wh= ilst=20 the lee flap is partially blocked by the fuselage - more left turning if th= e=20 wind is from the left. 
 
If power is applied rapidly at the start of a takeoff run or fast taxi= , the=20 left turning tendency is very strong.  It is best to apply power slowl= y=20 until rudder control is there. 
 
If all the left forcing factors are present, their effect is=20 additive.  Right brake tapping is useful. 
 
Grayhawk
 
PS If you are on the left side of a crowned taxiway or runway - well,= =20 there's another factor.
 
PPS I loved right crosswinds for takeoffs and landings.
 
PPPS - If one main gear leg is vertical and the other is not, there is= an=20 effect.
 
In a message dated 5/9/2014 7:05:47 A.M. Central Daylight Time,=20 snopercod@comporium.net writes:
=
In response to Greyhawk:

Toe out is an unstable=20 condition.
The jury seems to st= ill=20 be out on that subject. I can find experienced pilots who swear by either= =20 toe-in or toe-out. Since my toe-out condition is only a fraction of a deg= ree,=20 I'm just going to leave it alone for now. If it becomes a problem later o= n,=20 I'll fix the 0.6=BA tire with a shim at the base of the axle. The 0.2=BA = isn't=20 worth messing with. I want to get this plane flying sometime before I die= =20 (grin).
2.  If these are the original Matco wheels, note that th= e pin=20 bearing races are aligned conically.  Thus, one needs to make sure= the=20 axle nut (with washer on the inside shoulder and under the nut) is snug= ged=20 tight enough to keep the bearings properly supporting the wheel.  = Loose=20 wheels will destroy the bearings (nose wheel included).  The usual= rule=20 is that they are properly tight if the wheel will not make a compl= ete=20 revolution when hand spun whilst on jacks.  Remember to make sure = the=20 bearings are packed with appropriate=20 grease.
Yes, I have the original Matco wheels and the original Rosen= han=20 brakes. I've adjusted the axle nuts so the tire will spin 1-1/4 turns by = hand.=20 The bearings are snug that way, yet it leaves a little room for thermal= =20 expansion. We saw what happened when I turned the axle nut one flat beyon= d=20 that point and it wasn't pretty. Yes, the bearings are well packed with= =20 high-temperature grease. I checked that a few h= ours=20 ago.

3. The brake pad float bushings should allow the pad mounts t= o=20 move freely (SS not rusty steel) and properly positioned so that= =20 relaxing brake pedal pressure causes no pressure on the pad to the=20 rotor.
Check.
4. Remember that when steering - one toe presses (or jus= t=20 taps) the inside-the-turn pedal whilst the other foot holds the ru= dder=20 pedal steady so that you are not slamming the rudder=20 over.
That's the way I do it, but = after=20 all these years of using only brakes to steer the plane, I find I have to= =20 retrain my mind to stay off the brakes at over 30 KTs and let the rudder = do=20 the steering.

Thanks for the sage=20 comments.
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