X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 17 Feb 2010 14:38:55 -0500 Message-ID: X-Original-Return-Path: Received: from mailrelay.embarq.synacor.com ([208.47.184.3] verified) by logan.com (CommuniGate Pro SMTP 5.3.2) with ESMTP id 4128069 for lml@lancaironline.net; Wed, 17 Feb 2010 08:28:13 -0500 Received-SPF: pass receiver=logan.com; client-ip=208.47.184.3; envelope-from=liegner@embarqmail.com X-Original-Return-Path: X-BINDING: X-Spam-Rating: None X_CMAE_Category: 0,0 Undefined,Undefined X-CNFS-Analysis: v=1.1 cv=m6TfI3QcN6sIENZ12Wnh4AZi4/l4h2LsGqG4JwzO+yQ= c=1 sm=0 a=mLyA0xSwTAUA:10 a=4m3PS0BdG8L1/bKmPDH62A==:17 a=gKLyQ0ufAAAA:8 a=fLuM78UsAAAA:8 a=CjxXgO3LAAAA:8 a=LJNHRzvFAAAA:8 a=Ia-xEzejAAAA:8 a=I22tezhs1i2gR3MN-GwA:9 a=2bipDy23JFKPSRdtdwwA:7 a=6ejZ8VzRo7uMQQ0wXHU144kBTfoA:4 a=6e4CQMaF2vYA:10 a=3jk_M6PjnjYA:10 a=rC2wZJ5BpNYA:10 a=3q8PDF_K8bIA:10 a=ZgiNvqTx0KsnOPhe:21 a=GUn4Ea7KQVQHT6-d:21 a=WVbsZxusJWe2CMpm8TgA:9 a=7yTVo8N5w-ua4mxYG7gA:7 a=_qf-Cgv8rNJNz8PptcRtEpeNOeEA:4 a=Z3DjBptwbi6Y0xfs:21 a=E8ZPt907Xdhfn4vL:21 a=4m3PS0BdG8L1/bKmPDH62A==:117 X-CM-Score: 0 X-Scanned-by: Cloudmark Authority Engine Authentication-Results: smtp01.embarq.synacor.com smtp.user=liegner@embarqmail.com; auth=pass (LOGIN) Received: from [76.6.56.192] ([76.6.56.192:10482] helo=[192.168.32.116]) by mailrelay.embarq.synacor.com (envelope-from ) (ecelerity 2.2.2.40 r(29895/29896)) with ESMTPA id 92/0C-03357-8CEEB7B4; Wed, 17 Feb 2010 08:27:36 -0500 Mime-Version: 1.0 X-Sender: liegner@embarqmail.com@pop.embarqmail.com X-Original-Message-Id: In-Reply-To: References: X-Original-Date: Wed, 17 Feb 2010 08:07:42 -0500 X-Original-To: lml@lancaironline.net From: "Jeffrey Liegner, MD" Subject: Practicing Gear Down in Flight without Hand Pump Content-Type: multipart/alternative; boundary="============_-945709213==_ma============" --============_-945709213==_ma============ Content-Type: text/plain; charset="us-ascii" ; format="flowed" Slight Change of Thread: How many pilots are testing the nose gear down in flight in the absence of any hydralic pressure? After pulling the breaker and bleeding off hydralic pressure (with flaps), selecting gear down without hand pump, waiting for nose gear GREEN...are you specifically observing for this? Of course, I have practiced hand pump gear down emergency procedure in flight, but I do not recall waiting and observing the nose gear green light coming on before grabbing the hand pump. As Charlie says, this would be an important annual demonstration of the over center gas spring on the nose gear. I recall some people have trepidation about shutting down the engine and practicing best glide in coarse pitch. Not quite the same, but still an in flight demonstrated practice failure. Jeff L LIVP >Hi Bob, > >I think if you'll look LIV hydraulic schematic over, you will see >that -- the shuttle valve determines which pressure source to use. >If the electric hydraulic pump is inoperative--then the hand pump >will provide enough pressure to extend the main landing gears >provided the system is intact. > >Any leak after the gear selector will dump all (electric or hand >pump--in the down position) hydraulic pressure. That is why the >designers of this system installed the nose gear gas spring. > >Anything after the gear selector-- well render the hydraulics >inoperative. Including the hand pump. That is why the designer put a >gas spring to extend the nose gear. To save our wallets. > > >Charlie K. > >See me on the web at >www.Lancair-IV.com > > > > >From: "marv@lancair.net" >To: lml@yahoo.com >Sent: Tue, February 16, 2010 9:10:13 AM >Subject: [LML] Re: Turbine IVP Landing Accident Video > >Posted for "Robert Pastusek" : > > Laurie, > >First of all, a very nice job of taking care of this emergency! Also, thanks > so much for the report to the rest of us. As you note, these things always > provide useful information, and this one caused me to think again about my > own airplane. Most of my IV-P electrical system is protected with fuses; the > alternators and hydraulic pump being the exceptions, and with the CB's for > these made very readily accessible for just the situation you encountered. > My concern is that you didn't have sufficient hydraulic fluid to lower/lock > the gear with the manual pump. I determined during construction that the > pickup tube for the manual pump extended lower in the tank than the electric > pump pickup, and just let it go at that. I did not test this at all. > > > > If you have any thoughts about why you didn't have enough fluid left to use > the backup system, I'd be most appreciative. Could the pitch attitude of the > aircraft had an effect? Other thoughts? Based on your experience, I'm > thinking of draining down my system through the electric pump and then > trying the manual pump. Like I said, I took this one on faith of the > designer and did not test it, although it would have been easy to do during > build. > > > > Again, nice job landing the aircraft, and I'm happy you sustained minimal > damage in the process. Thanks especially for your comprehensive report. If > you find more, especially about why the emergency pump didn't work, we'd all > appreciate hearing. > > > > Bob Pastusek > >For LOBO > >-- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html --============_-945709213==_ma============ Content-Type: text/html; charset="us-ascii" Practicing Gear Down in Flight without Hand Pump
Slight Change of Thread:

How many pilots are testing the nose gear down in flight in the absence of any hydralic pressure?  After pulling the breaker and bleeding off hydralic pressure (with flaps), selecting gear down without hand pump, waiting for nose gear GREEN...are you specifically observing for this?

Of course, I have practiced hand pump gear down emergency procedure in flight, but I do not recall waiting and observing the nose gear green light coming on before grabbing the hand pump.  As Charlie says, this would be an important annual demonstration of the over center gas spring on the nose gear.

I recall some people have trepidation about shutting down the engine and practicing best glide in coarse pitch.  Not quite the same, but still an in flight demonstrated practice failure.

Jeff L
LIVP


Hi Bob,
I think if you'll look LIV hydraulic schematic over, you will see that -- the shuttle valve determines which pressure source to use. If the electric hydraulic pump is inoperative--then the hand pump will provide enough pressure to extend the main landing gears provided the system is intact.
Any leak after the gear selector will dump all (electric or hand pump--in the down position) hydraulic pressure. That is why the designers of this system installed the nose gear gas spring.
Anything after the gear selector-- well render the hydraulics inoperative. Including the hand pump. That is why the designer put a gas spring to extend the nose gear. To save our wallets.
 
Charlie K.
 
See me on the web at
www.Lancair-IV.com
 


From: "marv@lancair.net" <marv@lancair.net>
To: lml@yahoo.com
Sent: Tue, February 16, 2010 9:10:13 AM
Subject: [LML] Re: Turbine IVP Landing Accident Video
Posted for "Robert Pastusek" <rpastusek@htii.com>:

 Laurie,
 
First of all, a very nice job of taking care of this emergency! Also, thanks
 so much for the report to the rest of us. As you note, these things always
 provide useful information, and this one caused me to think again about my
 own airplane. Most of my IV-P electrical system is protected with fuses; the
 alternators and hydraulic pump being the exceptions, and with the CB's for
 these made very readily accessible for just the situation you encountered.
 My concern is that you didn't have sufficient hydraulic fluid to lower/lock
 the gear with the manual pump. I determined during construction that the
 pickup tube for the manual pump extended lower in the tank than the electric
 pump pickup, and just let it go at that. I did not test this at all.
 
 
 
 If you have any thoughts about why you didn't have enough fluid left to use
 the backup system, I'd be most appreciative. Could the pitch attitude of the
 aircraft had an effect? Other thoughts? Based on your experience, I'm
 thinking of draining down my system through the electric pump and then
 trying the manual pump. Like I said, I took this one on faith of the
 designer and did not test it, although it would have been easy to do during
 build.
 
 
 
 Again, nice job landing the aircraft, and I'm happy you sustained minimal
 damage in the process. Thanks especially for your comprehensive report. If
 you find more, especially about why the emergency pump didn't work, we'd all
 appreciate hearing.
 
 
 
 Bob Pastusek
 
For LOBO
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