X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 30 Apr 2009 19:55:26 -0400 Message-ID: X-Original-Return-Path: Received: from mta31.charter.net ([216.33.127.82] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3611810 for lml@lancaironline.net; Thu, 30 Apr 2009 12:15:17 -0400 Received-SPF: pass receiver=logan.com; client-ip=216.33.127.82; envelope-from=troneill@charter.net Received: from imp11 ([10.20.200.11]) by mta31.charter.net (InterMail vM.7.09.01.00 201-2219-108-20080618) with ESMTP id <20090430161436.VHEW2647.mta31.charter.net@imp11> for ; Thu, 30 Apr 2009 12:14:36 -0400 Received: from axs ([75.132.241.174]) by imp11 with charter.net id lsEb1b00F3mUFT705sEbVW; Thu, 30 Apr 2009 12:14:36 -0400 X-Original-Message-ID: <669BDA66446D4AE0AFAAB651B67F19C3@axs> From: "terrence o'neill" X-Original-To: "Lancair" Subject: LNC2 gear X-Original-Date: Thu, 30 Apr 2009 11:14:36 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0068_01C9C984.D8B6BB50" 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_0068_01C9C984.D8B6BB50 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable 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- 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. ! =20 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?=20 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/ ------=_NextPart_000_0068_01C9C984.D8B6BB50 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable

Here's an = interesting quirk of=20 the retract system, I think....

Yesterday, spurred = by a helpful=20 LML suggestion to increase the preload in my nose strut, I chocked the = mains,=20 weighted the tail, and supported the nose with the nosewheel an inch off = the=20 ground, in order to rotate the nosegear up a little in order to get an = air chuck=20 on the schroeder valve less than an inch behnd #3 exhaust=20 tube.

So I pushed up the = over-=20 still locked = up. So I=20 opened the free-fall valve. Pushed back the nose strut, chucked my = new $22.=20 / 300 psi made-in-china strut pump, on, and 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 the=20 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=20 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, and=20 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, then=20 here's a scenario to consider:

Gear down, no nose = green=20 light.

System pump or = 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=20 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 by PC Tools AntiVirus (5.0.0.22 - 10.100.057).
http://www.pctools.com/free-antivirus/
------=_NextPart_000_0068_01C9C984.D8B6BB50--