X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 17 Apr 2012 09:52:28 -0400 Message-ID: X-Original-Return-Path: Received: from [216.151.170.119] (HELO mta9.webminders.com) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTPS id 5484396 for lml@lancaironline.net; Mon, 16 Apr 2012 23:00:41 -0400 Received-SPF: none receiver=logan.com; client-ip=216.151.170.119; envelope-from=jskiba@icosa.net Received: from 76-234-41-197.lightspeed.cicril.sbcglobal.net ([76.234.41.197] helo=jskibaPC) by mta9.webminders.com with esmtpa (Exim 4.63) (envelope-from ) id 1SJyeC-0006lV-ES for lml@lancaironline.net; Mon, 16 Apr 2012 23:00:04 -0400 From: "Jeffrey W. Skiba" X-Original-To: "'Lancair Mailing List'" References: In-Reply-To: Subject: RE: [LML] Excessive down hydraulic pressure X-Original-Date: Mon, 16 Apr 2012 22:00:00 -0500 X-Original-Message-ID: <23e701cd1c46$300e62b0$902b2810$@icosa.net> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_23E8_01CD1C1C.473D15A0" X-Mailer: Microsoft Outlook 14.0 X-Antivirus: AVG for E-mail X-AVG-ID: ID297F8156-53D848FD Content-Language: en-us Thread-Index: AQI6XIKDbdGacz5QaMHSa3Tn7j1VfJXD0v3g X-Headers-Begin: 1SJyeC-0006lV-ES X-Authenticated-As: jskiba@icosa.net X-Headers-End: 1SJyeC-0006lV-ES This is a multipart message in MIME format. ------=_NextPart_000_23E8_01CD1C1C.473D15A0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Adam, =20 Are you running the Stock Lancair gear system or are you using your gear = system ? =20 Do you have the first generation pump or the high capacity one ? =20 =20 =20 From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Adam Molny Sent: Monday, April 16, 2012 7:14 AM To: lml@lancaironline.net Subject: [LML] Excessive down hydraulic pressure =20 On my fourth test flight I tested the normal and emergency gear = extension/retraction and everything worked fine. My first landing = attempt resulted in a go-around due to gusty winds. When I extended the = gear again on downwind nothing happened. After a few seconds of = head-scratching I momentarily cracked the dump valve. That fixed the = problem and the landing was uneventful (if a bit firm). = http://www.youtube.com/watch?v=3Dfo1qnhBuqS8 The attached JPG file shows the up and down hydraulic pressure readings = throughout the flight. The x-axis is time, with the flight beginning at = 20:32Z and ending at 21:12Z. You can see the gear retraction tests = beginning around 20:43 and 3500' altitude. Notice that after the last = test the down pressure remains around 500psi for about 90 seconds even = though the gear is retracted. The up pressure fluctuates a bit then the = down pressure drops to near zero.=20 The bottom graph is a closer view of the landing sequence. The go-around = occurs at 21:05Z. When I retracted the gear the up pressure went to = 950psi as expected, but the down pressure fluctuated around 500psi. This = kept the down pressure switch open, preventing gear extension. Does anyone have an idea as to what's causing the pressure buildup on = the down side?=20 Thanks, Adam Molny N181AM 6.1hrs hobbs time _____ =20 No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2411/4941 - Release Date: = 04/16/12 ------=_NextPart_000_23E8_01CD1C1C.473D15A0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

Adam,

Are you running the Stock Lancair gear system or are you using your = gear system ?

Do you have the first generation pump or the high capacity one = ?

From:= = Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Adam Molny
Sent: Monday, April 16, 2012 7:14 = AM
To: lml@lancaironline.net
Subject: [LML] = Excessive down hydraulic pressure

On my fourth test flight I = tested the normal and emergency gear extension/retraction and everything = worked fine. My first landing attempt resulted in a go-around due to = gusty winds. When I extended the gear again on downwind nothing = happened. After a few seconds of head-scratching I momentarily cracked = the dump valve. That fixed the problem and the landing was uneventful = (if a bit firm). http://www.youtube.= com/watch?v=3Dfo1qnhBuqS8

The attached JPG file = shows the up and down hydraulic pressure readings throughout the flight. = The x-axis is time, with the flight beginning at 20:32Z and ending at = 21:12Z. You can see the gear retraction tests beginning around 20:43 and = 3500' altitude. Notice that after the last test the down pressure = remains around 500psi for about 90 seconds even though the gear is = retracted. The up pressure fluctuates a bit then the down pressure drops = to near zero.

The bottom graph is a closer view = of the landing sequence. The go-around occurs at 21:05Z. When I = retracted the gear the up pressure went to 950psi as expected, but the = down pressure fluctuated around 500psi. This kept the down pressure = switch open, preventing gear extension.

Does anyone = have an idea as to what's causing the pressure buildup on the down = side?

Thanks,

Adam = Molny

N181AM 6.1hrs hobbs time

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.1913 / Virus Database: 2411/4941 - Release Date: = 04/16/12

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