An unusual use of the CVR

Date:         10 Jul 97 17:46:14 
From:         Steve Lacker <CAN_SPAM@arlut.utexas.eedu>
Organization: applied research laboratories
View raw article
  or MIME structure

A co-worker who knows I'm interested in both acoustics and aircraft
design stopped by my office a few weeks back and told me about a recent
paper he had co-authored. The paper explains a post-crash investigation
which had an unusual twist: an unused channel on the cockpit voice
recorder was utilized to detect vibrations in the airframe. Although the
channel wasn't connected to a sensor or microphone, all the wiring was
in place and when certain kinds of wire insulation are vibrated they
generate an electrostatic potential- basically a length of wire can act
as a very weak piezoelectric microphone. By analyzing the recorded
signal from this unused wire, they were able to detect the sound of a
failing engine mount prior to the crash.

The whole article is now available on the web at:

Stephen Lacker
Applied Research Laboratories, The University of Texas at Austin
PO Box 8029, Austin TX 78713-8029