Date: Sun, 2 Jan 2000 23:57:05 -0500
From: Lynda Frantz <LFrantz@compuserve.com>
Subject: 1 or 2 COMs
Sender: Lynda Frantz <LFrantz@compuserve.com>
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>Couldn't disagree more with Jim Franz about needing only one com radio.<

I guess I had one too many new year's grogs and was too outspoken.  But the
mail list seemed a bit slow over the holiday.  Nonetheless, I always get
lots of disagreement when I bring up the 1 or 2 COM issue.  I would not
suggest something without having tried it first.  I fly IFR with 1 COM and
a portable in my Lancair.  When I give flight reviews, I rarely see
students using the 2nd COM and occasionally see them miss ATC calls when
they do.  Did you ever notice that both COMs on most light aircraft are
wired to the same radio bus?  Not much redundancy there.   

Regarding single pilot IFR operations retrieving ATIS while at the same
time monitoring ATC; this is a procedure that is common but being
discouraged by experienced instructors and FAA examiners.   The proper
procedure is to request to go off freq to retreive the ATIS.  In this way
you are more likely to get the proper barometric pressure etc. and you
could not possibly miss or copy an ATC clearance incorrectly because ATC
agreed not to issue any.

I had a hard time planning my IFR  panel deviating from the traditional
stack.  I just had to put in a DME though.  I now realize that with GPS the
DME was mostly a waste of $$ and panel space and would not do it again. 
Oops, there I go again proposing trashing another standard IFR panel stack
component. 

Keep in mind that times are a-changing.  The old audio selector panel, 2
COM, 2 NAV, DME, ADF, Marker Beacon and transponder stack are no longer the
standard or even optimum for IFR flying these days.  Corporate and airline
operators are already receiving taxi and flight plan clearances via digital
means at just about all of the large airports eliminating much of the voice
chatter.  ATIS retrieval is via data links at even medium sided airports. 
GPS will continue to become more IFR significant especially for non
precision approaches at small airports and for enroute navigating.  ADFs
are being phased out.  Plan your panel accordingly.  It's OK to deviate
from the standard stack.  And as I proposed previously, consider only one
panel mounted COM leaving $$$ and room for more important equipment to take
you beyond Y2K.

Just for the record my IFR stack includes 1 COM, 1 NAV, 1 GPS, 1 DME, 1
marker beacon receiver and 1 transponder.  All of these are powered off the
Radio bus which has its normal feed from the power distribution bus and an
alternate feed from the esential bus with an isolation feature from the
power distribution bus. My second COM is a battery powered hand held.

Happy New Year,
Jim Frantz


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