“I experienced a
catastrophic failure of the Chelton Sport/Crossbox 425 coupling, fortunately in
VFR weather. . .
===============================================================================
Robert,
I am sorry to hear that
you have experienced trouble with the NAV425EX. Did you contact us for
support at that time? If you still have the serial number or part number
of the unit, I can verify for you if you had the updates that we started in
April of 2006. The failure you describe may be related to these updates
and the subsequent service bulletin.
Mike:
*** In March I contacted the purveyor of the
equipment, D2A, because I had purchased the
425 as a package from
D2A and not as an individual unit
from Crossbow. D2A said that the
current "fixes" on the 425 were not working but alternate solutions were
available. I had the options of 1.) awaiting the results of further
testing, 2.) upgrading at the difference in price to a 500 system, or 3.)
upgrading to a Pinpoint at no charge. In the interest of time (airplane
was a bother to fly on just the backup instruments and I did not want to wait
months more) and money (that 500 System ain't cheap!) I went with the
Pinpoint. With that GADAHRS there were no catastrophic crashes and the
little bit of hunting was fixed within a short period of time. Perhaps by summer
when all the testing was done the 425 would have worked fine too and today
might be a viable alternative. As I wrote: options are
wonderful. ***
In regards to your
request to post the fixes made to the unit, Crossbow has done this. In
fact, we have posted the process and fixes put that were put in place for this
update in great detail. I personally feel that we have provided more
detail than any other manufacturer that I am aware of including some of the
major players in the aviation industry. You can find the full posting of
all of the service bulletins we have issued using the following
link.
http://www.xbow.com/Support/service_letters.aspx
*** I followed your link and read service letters
http://www.xbow.com/Support/Support_pdf_files/Service_Letter_NAV425-06-02.pdf and related. There
is a fine description of the faults found and the corrections
taken, and the detail given is akin to ISO documentation for corrective
action. I like that a lot. I am assuming that based on the problems
discovered that the current hardware revision and all future products will
have more real-life testing for conditions like improper test limits,
weak GPS signal induced error, EMI errors induced my mic activation, etc.
Perhaps Crossbow built the 500 so well that you never realized what could happen
in a leaned-down model. ***
Crossbow
has completed over 40 of these updates since April of 2006 and we have also
continued to sell large numbers of NAV42X variants to other EFIS manufacturers
and general aviation consumers.
*** Since
my plane is drilled and wired for both units you might want to consider it
a test bed to evaluate your hardware against the Pinpoint. Contact me
offline if you would be interested. Always willing to participate in
aircraft-related improvement programs. lancair@ustek.com
***
Robert M.
Simon
ES-P
N301ES