Forum: Reliability & Maintainability Questions and Answers
Posted by: Juan Carlos Rodenas (firstname.lastname@example.org )
Date posted: Wed Oct 18 3:44:11 US/Eastern 2000
Subject: reliability of non-electrical component
I am trying to obtain the NPRD95 data, but I am in the process of find internal funds. The problem is that I am trying to obtain a reliability number for an offer to spanish air force. I haven´t found any data about failure rates for the next components:
- Electrohidraulic pressure switches. - Flowmeter - Electrovalves - Heat Exchanger (oil). Please any data that can be send will be appreciate. It is only a gross number, more detail number will be calculated when de design progress. Thank you in advance to all
Posted by: Dan Mahoney
Date posted: Thu Oct 12 12:37:21 US/Eastern 2000
Subject: Missile Reliability
Say an expensive fielded missile system has demonstrated its flight reliability goal after 50 flights, but then 20% of the missile is upgraded with a new subsystem. How many new flights must the system undergo to get back to its demonstrated reliability value? Another 50?, 20% of 50?, something else?!? Can you somehow use 80% of the past experience? What if only 1 tenth of 1 percent of the missile was changed? Would that change the requirement?
Any insights or guidance would be appreciated.
Posted by: Peet vd Merwe (email@example.com )
Organization:Grintek Electronic Systems
Date posted: Thu Oct 12 6:13:17 US/Eastern 2000
Subject: Reliability of PCB-Mounted relays
MIL-HDBK-217 is very severe when it comes to the usage of relays in avionics equipment in the AIF and ARW environments. A typical failure rate given for the following relay, in the AIF environment at 85 degr C, is 15: Relay, High Speed, armature balanced & short, 5V, DPDT, 1A, - TQ2-5V. (Cyclic rate 3.0, Current ratio 42, resistive load.) Have you perhaps got any feild data available which might suggest a better reliability for this type of relay under the above circumstances? or What is your general experience/opinion in this regard?
Posted by: Gerd Jonas (firstname.lastname@example.org )
Date posted: Wed Oct 11 3:20:33 US/Eastern 2000
Subject: MIL-HDBK-217F notice 2 section 16
In the past our printed circuits boards are plated through holes tech. The new standard is now SMD technologie. If you calculate the failure rate for the interconnection, for the SMD tech. the failure rate is much lower. Were I have to implemented the number of circuit planes? Is it possible to calculate the failure rate for SMD tech in differend modes? please answer as soon as possible.
regards Gerd Jonas
Posted by: Jean Marie Cloarec (Jean-Marie.email@example.com )
Date posted: Tue Oct 10 10:59:35 US/Eastern 2000
Subject: Reliability data
Is there someone who couldsend me a copy of information from RADC TR 88 124 about fiber optic failure rate ?
My fax (in FRANCE) : préfix + 298 37 96 20 (french number is 02 98 37 96 20) Thank you