Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 3.4.7) with ESMTP id 804446 for rob@logan.com; Thu, 28 Jun 2001 14:36:43 -0400 Received: from dewey.Cadwell.cadwell.com ([208.26.246.18]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71175U5500L550S0V35) with ESMTP id com for ; Thu, 28 Jun 2001 13:00:07 -0400 content-class: urn:content-classes:message Subject: Gyro failure backup MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Date: Thu, 28 Jun 2001 10:07:56 -0700 Message-ID: Thread-Topic: Gyro failure backup Thread-Index: AcD/9OFaMVG90F8USt6mfktuRqhcTg== From: "Carl Cadwell" To: X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> I received a Safety Warning letter #31 from Parker Aerospace. It points out the weakness of the pneumatic gyros and the potential hazard of a gyro failure from a failed vacuum pump, the need for partial panel training and proper scans that include the vacuum gage. I appreciate the manufacturer sending out this information. I am a little confused. Parker included an FAA safety bulletin (FAA-P-87400-52). It states "if you use your airplane for IFR flight, you should install either a back-up pneumatic power source or electrically powered stand-by gyroscopic instruments." The warning furnished by Parker states "1. A back-up pneumatic power source for the air driven gyros, or a back-up electric attitude gyro instrument must be installed in all aircraft which fly IFR." How does one get from "should" to "must"? Is the is the FAA speaking? Other more cynical may ask: Is this a "CYA" on Parker's behalf? Or Is this Parker' marketing department speaking wanting to boost sales of their backup gyros? Can anyone provide any clarity on the FAA requirements? Would anyone install a back up vacuum pump or second electrical artificial horizon? Other solutions? My solution is to replace the vacuum pump every 200 hours. Am I naive? What is the failure rate of vacuum pumps in 200 hours? Also, my autopilot is operated on the electrical H.S.I. The electrical system has a battery, alternator and a standby alternator. The autopilot is go/no-go item for me on hard IFR. P.S. My wife says to put in a back-up or she is not going to Oshkosh with me. Now we are getting to the real reason for the inquiry! See you in Oshkosh and maybe my wife. Carl Cadwell N25CL and 50 hours >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>