X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 03 Mar 2008 20:39:53 -0500 Message-ID: X-Original-Return-Path: Received: from smtp120.sbc.mail.re3.yahoo.com ([66.196.96.93] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with SMTP id 2775151 for lml@lancaironline.net; Mon, 03 Mar 2008 13:38:27 -0500 Received: (qmail 72790 invoked from network); 3 Mar 2008 18:38:26 -0000 Received: from unknown (HELO ?192.168.1.64?) (lorn@ameritech.net@69.208.121.35 with plain) by smtp120.sbc.mail.re3.yahoo.com with SMTP; 3 Mar 2008 18:38:25 -0000 X-YMail-OSG: zq8lHFkVM1kmXBAbtnWYVNay4eqJpoDlJF.cfMEIqlJV9SeU2Kb3YGaZenlG9PbOfWkGtoMhi_HUEI71JWAdQvEsKulsCJq2oSad5bH8uG8tO1mevhpPMeeatwzxj7HN5dQRSL4X1gZMZW0- X-Yahoo-Newman-Property: ymail-3 X-Original-Message-Id: From: Lorn H Olsen X-Original-To: Lancair List Content-Type: text/plain; charset=ISO-8859-1; format=flowed; delsp=yes Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Apple Message framework v919.2) Subject: Gear Wouldn't Come Up X-Original-Date: Mon, 3 Mar 2008 13:38:24 -0500 X-Original-Cc: Martha Jane Jones X-Mailer: Apple Mail (2.919.2) It finally happened to me. A number of times as I have come down to =20 land, the gear hydraulic pump has not come on when the gear switch is =20= put down. A quick opening and closing of the dump valve eliminates the =20= problem. This time the gear wouldn't go up and I could not solve the =20 problem in flight. Last weekend I flew for 2 hours from Detroit to Newport News, Va and 4 =20= hours back. Going down on 02/28/08 the temp was -14=B0C at 11,500 ft. =20= Coming back 2 days later the temp was +15=B0C. My GPS recorded 244 kts =20= on the way down. Back it was 125 kts. Back on the ground, after the takeoff where the gear wouldn't come up, =20= I took out the passenger seat and looked at the gear pressure gauges. =20= The up gauge read 700 lbs and the down gauge read 1,500 lbs. The 30=B0C temperature raise must have taken the down side and raised =20= the pressure to over 1,500 lbs. It looks like enough of this high =20 pressure escaped to the high side to stop the pump from starting up. I =20= loosened a nut on the low side and the pressures went to zero. After =20 tightening the nut, I opened and closed the dump valve and turned the =20= master on and off. The low side recharged, the high side stayed at =20 zero and I left to return home. In conclusion, I think that from now on, I will open and close the =20 dump valve to remove pressure from the hydraulic system when the plane =20= is parked. As part of my startup checklist, I am adding: Master On, gear pump ran to charge the down side. -- Lorn H. 'Feathers' Olsen, MAA, ASMEL, ASES, Comm, Inst DynaComm, Corp., 248-345-0500, mailto:lorn@dynacomm.us LNC2, FB90/92, O-320-D1F, 1,300 hrs, N31161, Y47, SE Michigan