X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 22 Feb 2012 12:36:00 -0500 Message-ID: X-Original-Return-Path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTP id 5410055 for lml@lancaironline.net; Wed, 22 Feb 2012 10:43:36 -0500 Received-SPF: none receiver=logan.com; client-ip=71.74.56.122; envelope-from=Wolfgang@MiCom.net X-Original-Return-Path: X-Authority-Analysis: v=2.0 cv=d9t3OGfE c=1 sm=0 a=MHZY6FYWMEQOp7S43i2QIw==:17 a=3Zlka_XeuxsA:10 a=DTcCN-Bu46AA:10 a=ttCsPuSJ-FAA:10 a=Ia-xEzejAAAA:8 a=5FIZSGrRAAAA:8 a=rTjvlri0AAAA:8 a=o1OHuDzbAAAA:8 a=kprT2Xn8oynRFyAx4G8A:9 a=J_g-jLtVYmQmfpXGjqkA:7 a=wPNLvfGTeEIA:10 a=CVU0O5Kb7MsA:10 a=wR8WdYEwGqoA:10 a=EzXvWhQp4_cA:10 a=Dr9Wx-Q63l4A:10 a=ILCZio5HsAgA:10 a=CjxXgO3LAAAA:8 a=A9bSbmy0NXqZ8CiYQYEA:9 a=JXUP92mVKv0Wt89ltoEA:7 a=rC2wZJ5BpNYA:10 a=MHZY6FYWMEQOp7S43i2QIw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.218.201.50 Received: from [74.218.201.50] ([74.218.201.50:1082] helo=lobo) by hrndva-oedge04.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 26/92-26054-40D054F4; Wed, 22 Feb 2012 15:43:00 +0000 X-Original-Message-ID: <005101ccf178$a63989e0$6701a8c0@lobo> From: "Wolfgang" X-Original-To: References: Subject: Re: [LML] Re: 320/360 Hydraulic Pressure Switch X-Original-Date: Wed, 22 Feb 2012 10:42:57 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004E_01CCF14E.BD2C9360" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_004E_01CCF14E.BD2C9360 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable We can keep this up for the next year but I believe talking it to death = will not fix the problem. My preference is to have a system that takes = care of itself. You seem to want to be "involved" in the anomalies of = flight. If most people wanted to be "involved", we wouldn't have things = like FADEC's and auto pilots. The module I provide can help keep flight = a bit more self sufficient and safer. If you could convince Oildyne and = Lancair that they have a problem with the pumps as used in Lancairs, and = fix the problem, then more power to you and the Lancair owners. But in = the mean time. I still like my gear module. Wolfgang ----- Original Message -----=20 From: Chris Zavatson=20 To: lml@lancaironline.net=20 Sent: Tuesday, February 21, 2012 9:01 AM Subject: Re: [LML] Re: 320/360 Hydraulic Pressure Switch " . . . you can only override one pressure switch at a time or = overload the system. You need one switch each for the up and down. In the event of a = problem you have to make sure you push the right switch"... Overload what exactly? The gear selector determines which pressure = switch is powered. If you jumper across an unpowered switch, nothing = happens. =20 While I do not advocate putting in switches to mask a pump problem = that should really be investigated and fixed at the source, momentary = switches have other benefits. =20 1. Checking the relief valve settings in the pump. By holding down = the switch, one can see the relief valve setting of the pump. 2. Back-up for a failed pressure switch. This was more common with = the VEP switches, but current version is not immune.=20 3. Recharging the system on demand - The hysteresis loop on the = pressure switches is quite large. The gear can start to sag before the = pressure switch recharges the system. This is more of an issue for the = Outback Gear due to the higher aerodynamic loads pulling on the gear.=20 With automation and complexity come new failure modes. Give the pilot = enough information about the state of the aircraft systems to figure out = what happened and enough controls to solve the problem. Last summer when the high pressure switch went out, the pump shut off = before the gear was all the way up. Higher than normal air noise was = the first clue. A quick look at the pressure gauges revealed the high = side at only 800 psi. The momentary switch pulled the gear the rest of = the way up. Examination of the pressure switch uncovered intermittent = electrical contact within the switch when pressurized.=20 Chris Zavatson N91CZ 360std www.N91CZ.net From: Wolfgang To: lml@lancaironline.net=20 Sent: Monday, February 20, 2012 4:58 AM Subject: [LML] Re: 320/360 Hydraulic Pressure Switch Yes, that would be easy . . . except . . . you can only override one = pressure switch at a time or overload the system. You need one switch each for the up and down. In the event of a = problem you have to make sure you push the right switch. If you come up with some more complicated wiring, you could make it = work with only one switch for both up and down but you still have to = push the button if something isn't working as required. . . . or . . . you could put in a completely automatic system . . . Wolfgang ----- Original Message ----- From: "Greenbacks, UnLtd." = To: Sent: Friday, February 17, 2012 1:07 PM Subject: Re:320/360 Hydraulic Pressure Switch Seems to me the simplest and least expensive option would be to = install a momentary on switch in the cockpit to override and close the = open pressure switches. Just my 2 cents. Angier Ames N3ZQ=20 -- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html ------=_NextPart_000_004E_01CCF14E.BD2C9360 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
We can keep this up for the next year = but I believe=20 talking it to death will not fix the problem. My preference is to have a = system=20 that takes care of itself. You seem to want to be "involved" in the = anomalies of=20 flight. If most people wanted to be "involved", we wouldn't have things = like=20 FADEC's and auto pilots. The module I provide can help keep flight a bit = more=20 self sufficient and safer. If you could convince Oildyne and Lancair = that they=20 have a problem with the pumps as used in Lancairs, and fix the problem, = then=20 more power to you and the Lancair owners. But in the mean time. I still = like my=20 gear module.
 
Wolfgang
 
----- Original Message -----
From:=20 Chris=20 Zavatson
Sent: Tuesday, February 21, = 2012 9:01=20 AM
Subject: Re: [LML] Re: 320/360 = Hydraulic=20 Pressure Switch

" . . . you can = only=20 override one pressure switch at a time or overload the system.
You = need one=20 switch each for the up and down. In the event of a problem you have to = make=20 sure you push the right switch"...
 
Overload what=20 exactly?  The gear selector determines which pressure switch is=20 powered.  If you jumper across an unpowered switch, nothing happens.  =
While I = do not=20 advocate putting in switches to mask a pump problem that should really = be=20 investigated and fixed at the source, momentary switches have = other=20 benefits. 
 
1.  = Checking the=20 relief valve settings in the pump.  By holding down the switch, = one can=20 see the relief valve setting of the pump.
2.  Back-up for a failed = pressure=20 switch.  This was more common with the VEP switches, but current = version=20 is not immune. 
3.  = Recharging the=20 system on demand - The hysteresis loop on the pressure switches is = quite=20 large.  The gear can start to sag before the pressure switch recharges the = system. =20 This is more of an issue for the Outback Gear due to the = higher=20 aerodynamic loads pulling on the gear. 
 
With automation and=20 complexity come new failure modes.  Give the pilot enough=20 information about the state of the aircraft systems to figure out what = happened and enough controls to solve the problem.
Last summer = when the=20 high pressure switch went out, the pump shut off before the gear = was all=20 the way up.  Higher than normal air noise was the first = clue.  A=20 quick look at the pressure gauges revealed the high side at only 800=20 psi.   The momentary switch pulled the gear the rest=20 of the way up.   Examination of the pressure switch = uncovered=20 intermittent electrical contact within the switch = when=20 pressurized. 
 
Chris = Zavatson
N91CZ
360std
www.N91CZ.net
 
 
From: Wolfgang=20 <Wolfgang@MiCom.net>
To: lml@lancaironline.net =
Sent: Monday, February 20, 2012 = 4:58=20 AM
Subject: [LML] = Re: 320/360=20 Hydraulic Pressure Switch

Yes, that would be easy = . . .=20 except . . . you can only override one pressure switch at a time or = overload=20 the system.
You need one switch each for the up and down. In the = event of a=20 problem you have to make sure you push the right switch.
If you = come up=20 with some more complicated wiring, you could make it work with only = one switch=20 for both up and down but you still have to push the button if = something isn't=20 working as required.
. . . or . . . you could put in a completely = automatic=20 system . . .

Wolfgang

----- Original Message ----- From: = "Greenbacks, UnLtd." <N4ZQ@VERIZON.NET>
To: = <lml@lancaironline.net>Sent:=20 Friday, February 17, 2012 1:07 PM
Subject: Re:320/360 Hydraulic = Pressure=20 Switch


Seems to me the simplest and least expensive option = would be=20 to install a momentary on switch in the cockpit to override and close = the open=20 pressure switches.

Just my 2 cents.

Angier Ames
N3ZQ=20


--
For archives and unsub=20 = http://mail.lancaironline.net:81/lists/lml/List.html


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