George,

At 09:26 AM 8/13/97 -0400, you wrote:
>I am also looking for any requirement specs.
>If a Boeing Engineer wanted to place some electronics near the engines,
>vibration should be expected and taken into consideration at design.  Is
>there a design/production spec for circuit card assemblies which include
>requirements to meet some vibration/shock criteria?  How are these
>requirements invoked now that Mil-C-28809B is gone?

Generally, vibration and shock requirements are applicable to an entire
assembly (e.g. a chassis populated with boards) and not just circuit cards
since the entire assembly is what is actually exposed to the vibration and
shock environment in field usage.

>What shock and vibration requirements are placed on the famous Flight Data
>Recorders searched for and recovered after airline crashes?  They have
>boards in them, right?

Flight Data Recorders and Cockpit Voice Recorders consist of a chassis with
circuit cards and a crash housing which has either tape or solid state
memory (on small circuit cards) inside.  RTCA DO-160C details the
environmental requirements (including vibration) for the recorders and the
more intense crash survival testing requirements for the crash housings.


Brian Hyde
Reliability Engineer
L-3 Communications Aviation Recorders
E-mail: [log in to unmask]

--------------------------------------------
Brian P. Hyde
Reliability Engineer
L-3 Communications
Aviation Recorders Division
(941)371-0811, ext. 5136
E-Mail: [log in to unmask]
--------------------------------------------