X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 01 May 2009 16:26:59 -0400 Message-ID: X-Original-Return-Path: Received: from mta21.charter.net ([216.33.127.81] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3612815 for lml@lancaironline.net; Fri, 01 May 2009 10:37:44 -0400 Received-SPF: pass receiver=logan.com; client-ip=216.33.127.81; envelope-from=troneill@charter.net Received: from imp10 ([10.20.200.10]) by mta21.charter.net (InterMail vM.7.09.01.00 201-2219-108-20080618) with ESMTP id <20090501143700.BBRC3344.mta21.charter.net@imp10> for ; Fri, 1 May 2009 10:37:00 -0400 Received: from axs ([75.132.241.174]) by imp10 with charter.net id mEcz1b00Q3mUFT705Ed08X; Fri, 01 May 2009 10:37:00 -0400 X-Original-Message-ID: From: "terrence o'neill" X-Original-To: "Lancair Mailing List" References: Subject: [LML] LNC2 gear X-Original-Date: Fri, 1 May 2009 09:37:01 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0010_01C9CA40.61653470" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0010_01C9CA40.61653470 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Typo one-=3Dline correction to my last on the gar... line 5... = correction underlined. ----- Original Message -----=20 From: terrence o'neill=20 To: lml@lancaironline.net=20 Sent: Thursday, April 30, 2009 18:55 Subject: [LML] LNC2 gear Here's an interesting quirk of the retract system, I think.... Yesterday, spurred by a helpful LML suggestion to increase the preload = in my nose strut, I chocked the mains, weighted the tail, and supported = the nose with the nosewheel an inch off the ground, in order to rotate = the nosegear up a little in order to get an air chuck on the schroeder = valve less than an inch behnd #3 exhaust tube. So I pushed up the over- -center brace and pushed back the strut which = moved back a little... which reisted .... still locked up. So I opened = the free-fall valve. Pushed back the nose strut, chucked my new $22. / = 300 psi made-in-china strut pump, on, and put in the max. =20 Then lowered the nosewheel to over-center lock, lowered the nose, = removed the weight on the tail, and observed 3 inches of strut! So I pulled the plane out to run an engine idle check, and glanced at = the right wing, was shocked to see the gear leaning inward about 10 = degrees. ! I managed to get the jack in place and raise the wing enough to push = the gear in place and pull the over-center strut to lock. Checked the left gear... and found its over-center strut pushed up, = unlocked, too! Jacked and pulled it down, and then put the plane back in the hangar = and ran a retract-extend check -- after putting the free-fall valve back = in closed position. My guess is that with the hydraulic system closed/normal, in pushing = the nosegear over-center lock up and pushing back on the nosewheel I = also hydraulic-pressured the main cylinders to pull their over-center = locks up. So, if this is true, then here's a scenario to consider: Gear down, no nose green light. System pump or solenoid CB pops. =20 SO, pull the pump CB, gear switch in Down, valve to free-fall. Still can't get a nose green light. Just the mains. To land, should the free-fall valve be left open, or moved to closed? = If it is moved to closed, and the nosegear is not locked = over-center... will aft pressure on touchdown unlock the mains too, = damaging not only the prop/engine but also the gear and fuselage? Terrence L235/320 N211AL No virus found in this outgoing message Checked by PC Tools AntiVirus (5.0.0.22 - 10.100.057). http://www.pctools.com/free-antivirus/ No virus found in this incoming message Checked by PC Tools AntiVirus (5.0.0.22 - 10.100.057). http://www.pctools.com/free-antivirus/ No virus found in this outgoing message Checked by PC Tools AntiVirus (5.0.0.22 - 10.100.057). http://www.pctools.com/free-antivirus/ ------=_NextPart_000_0010_01C9CA40.61653470 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Typo one-=3Dline = correction to my=20 last on the gar... line 5... correction underlined.
----- Original Message -----
From:=20 terrence=20 o'neill
Sent: Thursday, April 30, 2009=20 18:55
Subject: [LML] LNC2 gear

Here's an = interesting quirk=20 of the retract system, I think....
Yesterday, = spurred by a=20 helpful LML suggestion to increase the preload in my nose strut, I = chocked the=20 mains, weighted the tail, and supported the nose with the nosewheel an = inch=20 off the ground, in order to rotate the nosegear up a little in order = to get an=20 air chuck on the schroeder valve less than an inch behnd #3 = exhaust=20 tube.
So I pushed up = the over-=20 -center brace and pushed back the strut which moved back a = little... which=20 reisted .... still locked up. So I opened the free-fall valve. Pushed = back the=20 nose strut, chucked my new $22. / 300 psi made-in-china strut pump, = on, and=20 put in the max. 
Then lowered the = nosewheel=20 to over-center lock, lowered the nose, removed the weight on the = tail, and=20 observed 3 inches of strut!
So I pulled the = plane out to=20 run an engine idle check, and glanced at the right wing, was shocked = to see=20 the gear leaning inward about 10 degrees. !
 
I managed to get = the jack in=20 place and raise the wing enough to push the gear in place and pull the = over-center strut to lock.
Checked the left = gear... and=20 found its over-center strut pushed up, unlocked, =  too!
Jacked and pulled = it down,=20 and then put the plane back in the hangar and ran a retract-extend = check=20 -- after putting the free-fall valve back in closed=20 position.
My guess is that = with=20 the hydraulic system closed/normal, in pushing the nosegear = over-center=20 lock up and pushing back on the nosewheel I also hydraulic-pressured = the main=20 cylinders to pull their over-center locks up.
 
So, if this = is true,=20 then here's a scenario to consider:
Gear down, no = nose green=20 light.
System pump = or=20 solenoid CB pops. 
SO, pull the pump = CB, gear=20 switch in Down, valve to free-fall.
Still can't get a = nose green=20 light. Just the mains.
 
To land, should = the free-fall=20 valve be left open,  or moved to closed? 
 
If it is moved to = closed, and the nosegear is not locked over-center... will aft = pressure=20 on touchdown unlock the mains too, damaging not only the prop/engine = but also=20 the gear and fuselage?
 
Terrence
L235/320=20 N211AL


No virus found in this outgoing = message
Checked=20 by PC Tools AntiVirus (5.0.0.22 - 10.100.057).
http://www.pctools.com/fr= ee-antivirus/


No=20 virus found in this incoming message
Checked by PC Tools AntiVirus=20 (5.0.0.22 - 10.100.057).
http://www.pctools.com/fr= ee-antivirus/


No virus found in this outgoing message
Checked by PC Tools AntiVirus (5.0.0.22 - 10.100.057).
http://www.pctools.com/free-antivirus/
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