Forum: Reliability & Maintainability Questions and Answers
Posted by: LEE FOSTER (LEE@DOWCO.CO.UK ) Date posted: Mon Mar 19 9:44:26 US/Eastern 2001 Subject: RELIABILITY Message: How are reliability pridictions made for 1 off, job lots, batches and maxx production
Posted by: Ken Burgess (burgessfk@raytheon.com ) Organization:Raytheon AIS Date posted: Wed Mar 7 13:52:28 US/Eastern 2001 Subject: Humidity Effects on Reliability Message: I am trying to ascertain the effects of humidity on component reliability. The purpose is to determine if dehumidifying an aircraft and its installed systems while on the ground is cost effective from a reliability perspective. The aircraft will be stationed in the UK where relatively high humidity is present in a relatively cool environment. This is contrary to where higher temperatures are usually associated with higher humidity. Does anyone know where I can find any data on humidity and the effects on reliability of airborne electronic systems? I am particularly interested in the time period that the systems are not operating.
Posted by: Ken Burgess (burgessfk@raytheon.com ) Date posted: Tue Mar 6 15:07:02 US/Eastern 2001 Subject: FRACAS Tracking Software Message: I am looking for a FRACAS software application. I know there are several available that track failure modes and trends, but I am trying to find one that tracks/compares failure rates experienced to predicted or some performance baseline. I know of one that calculates an MTBF, but no place to track against a baseline within the application.
Posted by: Alan Wild (awild@ferranti-technologies.co.uk ) Organization:Ferranti Technologies Ltd Date posted: Tue Mar 6 11:18:34 US/Eastern 2001 Subject: Mechanical or Solid State Relays? Message: Can anyone supply me with information to support a decision on component reliability for a rail application? Which are more reliable, mechanical or solid state relays? Mil-217 analysis (GM environment @ 50 deg C) shows mechanical solonoid types (based on predicted design stresses etc.) to be 0.14 FPMH against Solid state type of 0.35 FPMH. Does anyone out there have any actual recorded results to support or disagree with these predicted results?
Posted by: Leroy Meyers (meyers@drs-fsc-comm.com ) Organization:DRS Communications Date posted: Mon Feb 26 15:47:55 US/Eastern 2001 Subject: Press Fit Connectors Message: For a new design, we need a 160 pin connector for a motherboard. In the past, we used 96 pin MIL connectors that could be solder connected to the board. Now it seems that only the Press Fit style is available (a DIN variation). This is for a Military Aircraft application. 1. How would I model the connecTIONS in MIL-HDBK-217F (section 17.1)? Is this considered crimp? 2. I looked in Prism for RAC data, but there is nothing called Press Fit. Would 'Pressure Type' be appropriate? 3. From a practical standpoint, how would these press fit connectors hold up in my environment as compared to the solder version? Any experience out there? Note: I will be on vacation for the remainder of this week.
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