X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 16 Feb 2010 20:41:38 -0500 Message-ID: X-Original-Return-Path: Received: from web62508.mail.re1.yahoo.com ([69.147.75.100] verified) by logan.com (CommuniGate Pro SMTP 5.3.2) with SMTP id 4127006 for lml@lancaironline.net; Tue, 16 Feb 2010 13:32:28 -0500 Received-SPF: none receiver=logan.com; client-ip=69.147.75.100; envelope-from=charliekohler@yahoo.com Received: (qmail 4505 invoked by uid 60001); 16 Feb 2010 18:31:54 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=nBNc5pqjUcINE9WfN9YXK8Pm+8+YR+pAH/WTNdZdl77ZH6aoYJXmTqVt9oP5iJ3DAHhcHN170KcgaG4XK9G4Zy+W6RreVQlB/ulTBSdp+RcAQQGOkQfMw0JUZNDRNfI8des2xjEV774Bkz/E6YBGqX7CvcjWf07iAtDdjGbqcPg=; X-Original-Message-ID: <505476.4237.qm@web62508.mail.re1.yahoo.com> X-YMail-OSG: NtvHJJ8VM1mgk5ZHPuk.8CdGZvBLBp4gbYl.rFqlRhofNi4gwbxyg6W9A4vJJX.Aqsz2S7kVeB1bErC7d9GK7bcoQ8sTsSPx1h9IEfCM6mCWo5OcEjJkjZDkjUyiyUD6U8HLXdHJrXYhIEu6MVOH3PCDL.SyYGb1MvrHpNpDReafcqX83XILxQIR0XMWSMqaULB.dTXLyz.3IJ3x3kO7qxJ.AklvBZHYHMWhHWgbB_HOLErW0l0GUwb_McwsqdtiLZfqVzl.h59wfu.0m65vcIYi76VA7lTmgk5eGRQjXHWqC_v7OH3q.Ff9lsS4qQYZPIWnvXH5hxTO2DLfhANOIlmThoj58awymp2S Received: from [68.204.28.90] by web62508.mail.re1.yahoo.com via HTTP; Tue, 16 Feb 2010 10:31:54 PST X-Mailer: YahooMailRC/300.3 YahooMailWebService/0.8.100.260964 References: X-Original-Date: Tue, 16 Feb 2010 10:31:54 -0800 (PST) From: Charlie Kohler Subject: Re: [LML] Re: FW: [LML] Turbine IVP Landing Accident Video X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1657704560-1266345114=:4237" --0-1657704560-1266345114=:4237 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Laurie=0A=0A"I test the gas strut each 100 hours and it was replaced 120 ho= urs ago. It=0A=A0works fine on a retraction test but I guess it couldn't ov= ercome the=0A=A0airloads."=0A=0AThe difference between a retraction test on= jacks -- and an inflight test-- is the airload -as you say. That is why it= should be tested in flight - regularly. If it won't put the nose gear=A0do= wn in flight --=A0 you may have a misalignment of the trunions/links/ actua= tor etc etc. At any rate -- it should be fixed. If it's the airload and the= gear swings free when disconnected and up on jacks -- put the gas spring a= nd push it down on a bath scale to test it. =0A=0ACharlie K.=0A=0ASee me on= the web at =0Awww.Lancair-IV.com=0A=0A=0A=0A=0A=0A________________________= ________=0AFrom: "marv@lancair.net" =0ATo: lml@yahoo.com= =0ASent: Tue, February 16, 2010 1:17:43 PM=0ASubject: [LML] Re: FW: [LML] T= urbine IVP Landing Accident Video=0A=0A=0APosted for Laurie Fitzgerald (lau= rie@lauriefitzgerald.com):=0A=0A=0A=A0Bob... when building the aircraft I r= ealised that a failure of either of the=0A=A0flexible lines from the shuttl= e valve to the main gear rams would result in=0A=A0the dual failure of elec= tric and manual system.=0A=A0=0A=A0=0A=A0=0A=A0To help overcome this I repl= aced the 3000psi lines supplied with the kit=0A=A0with 25000psi flexible ho= se and had it pressure tested and certified to=0A=A015000psi I didn't want = to test to the full 25000psi and take the system to=0A=A0the verge of failu= re.=0A=A0=0A=A0=0A=A0=0A=A0When the system failed I was certain it must hav= e been caused by the failure=0A=A0of one of these flexible lines.=A0=A0I wa= s surprised to find the failed flare=0A=A0fitting on an aluminum line but n= ow=0A=A0=0A=A0realise that the manual pump is merely a backup for an electr= ical failure=0A=A0and in most cases is of little value if an hydraulic line= is breached. One=0A=A0exception might be the flexible line on the flap sys= tem as this is=0A=A0restricted and if=0A=A0=0A=A0you act quickly you may ge= t the gear down.=0A=A0=0A=A0=0A=A0=0A=A0My rear carpet is testimony to the = fact there was no shortage of hydraulic=0A=A0fluid.=0A=A0=0A=A0=0A=A0=0A=A0= Charlie thanks for the comment on the gas strut. You are correct this was a= =0A=A0failure or at least an unintended consequence.=0A=A0=0A=A0=0A=A0=0A= =A0I test the gas strut each 100 hours and it was replaced 120 hours ago. I= t=0A=A0works fine on a retraction test but I guess it couldn't overcome the= =0A=A0airloads.=0A=A0=0A=A0=0A=A0=0A=A0I realise some Lancair IV-P piston p= owered aircraft are landing much slower=0A=A0than me and this may be a fact= or in deployment of the nose gear.=0A=A0=0A=A0=0A=A0=0A=A0On reflection, I = am happy to accept the prop and engine damage and should I=0A=A0be in this = situation again I would prefer the nose gear did not deploy as I=0A=A0belie= ve=0A=A0=0A=A0the stress associated with taking the entire load on the rudd= er and nose=0A=A0wheel would likely over stress the airframe in the region = of the baggage bay=0A=A0door resulting in compression damage to the=0A=A0= =0A=A0hull.=0A=A0=0A=A0=0A=A0=0A=A0Also I believe the wing which takes the = load will be more likely to cause a=0A=A0ground loop or rupture a wing tank= .=0A=A0=0A=A0=0A=A0=0A=A0I cannot be sure of the above but sometimes it's b= etter the devil you know.=0A=A0=0A=A0=0A=A0=0A=A0Either way in the end it's= an expensive Bob sled ride.=0A=A0=0A=A0=0A=A0=0A=A0Cheers=0A=A0=0A=A0=0A= =A0=0A=A0Laurie=0A=A0=0A=A0=0A=0A-- For archives and unsub http://mail.l= ancaironline.net:81/lists/lml/List.html --0-1657704560-1266345114=:4237 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
=0A
Laurie
=0A
 
=0A
"I test the= gas strut each 100 hours and it was replaced 120 hours ago. It
 wo= rks fine on a retraction test but I guess it couldn't overcome the
 = ;airloads."
=0A
The difference between a retraction test on ja= cks -- and an inflight test-- is the airload -as you say. That is why it sh= ould be tested in flight - regularly. If it won't put the nose gear do= wn in flight --  you may have a misalignment of the trunions/links/ ac= tuator etc etc. At any rate -- it should be fixed. If it's the airload and = the gear swings free when disconnected and up on jacks -- put the gas sprin= g and push it down on a bath scale to test it.
=0A
 
= =0A
Charlie K.
=0A
 
=0A
See me on the web at =0A=0A
 
=0A

= =0A
=0A
=0AFrom: "marv@lancair.net" <marv@l= ancair.net>
To: lml@y= ahoo.com
Sent: Tue, Febr= uary 16, 2010 1:17:43 PM
Subject: [LML] Re: FW: [LML] Turbine IVP Landing Accident Video
=
=0A
Posted for Laurie Fitzgerald (laurie@lauriefitzgerald.com)= :


 Bob... when building the aircraft I realised that a fail= ure of either of the
 flexible lines from the shuttle valve to the = main gear rams would result in
 the dual failure of electric and ma= nual system.
 
 
 
 To help overcome this I= replaced the 3000psi lines supplied with the kit
 with 25000psi fl= exible hose and had it pressure tested and certified to
 15000psi I= didn't want to test to the full 25000psi and take the system to
 t= he verge of failure.
 
 
 
 When the system= failed I was certain it must have been caused by the failure
 of o= ne of these flexible lines.  I was surprised to find the failed f= lare
 fitting on an aluminum line but now
 
 realis= e that the manual pump is merely a backup for an electrical failure
 = ;and in most cases is of little value if an hydraulic line is breached. One=
 exception might be the flexible line on the flap system as this i= s
 restricted and if
 
 you act quickly you may get= the gear down.
 
 
 
 My rear carpet is te= stimony to the fact there was no shortage of hydraulic
 fluid.
&= nbsp;
 
 
 Charlie thanks for the comment on the ga= s strut. You are correct this was a
 failure or at least an uninten= ded consequence.
 
 
 
 I test the gas stru= t each 100 hours and it was replaced 120 hours ago. It
 works fine = on a retraction test but I guess it couldn't overcome the
 airloads= .
 
 
 
 I realise some Lancair IV-P piston= powered aircraft are landing much slower
 than me and this may be a factor in deployment of the nose gear.
 
 
&nb= sp;
 On reflection, I am happy to accept the prop and engine damage= and should I
 be in this situation again I would prefer the nose g= ear did not deploy as I
 believe
 
 the stress asso= ciated with taking the entire load on the rudder and nose
 wheel wo= uld likely over stress the airframe in the region of the baggage bay
&nb= sp;door resulting in compression damage to the
 
 hull.
=  
 
 
 Also I believe the wing which takes the= load will be more likely to cause a
 ground loop or rupture a wing= tank.
 
 
 
 I cannot be sure of the above= but sometimes it's better the devil you know.
 
 
 = ;
 Either way in the end it's an expensive Bob sled ride.
 
 
 
 Cheers
 
  
 Laurie
 
 
=0A

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