On Jun 4, 11:21 am, "Peter R." wrote:
I was listening to LiveATC.net's feed of Syracuse, NY, yesterday (Sunday)
during the approach of a large thunderstorm line that was moving towards the
airport from the south. At one point a VFR a Cessna 172, approaching the
airport from the west, checked in stating his intention to land at SYR.

As the C172 progressed, the controller called the pilot to report that the
aircraft was eight miles from and heading directly towards a line of extreme
weather. The pilot responded in a somewhat unappreciative tone that he was
"painting" it. The controller responded with a rather surprised, "Roger."

Moments later the controller again called to warn the pilot of extreme
weather at his twelve o'clock. The pilot then replied in what sounded like an
annoyed tone that he was "picking our way through the weather using our XM."
Again, the controller replied with a surprised "Roger."

With a quiet moment on the frequency, the controller called the pilot a third
time to ask him to explain what XM meant. The pilot described the concept of
XM NEXRAD on his Garmin 396, but then added that the refresh rate allowed him
to see heavy weather on the 398 from 2 to 8 minutes old.

When I heard that the refresh rate was up to 8 minutes old, I cringed to
think that this pilot (this one didn't sound like an experienced freight dog
to me, but maybe I was wrong) was picking his way through a field of
thunderstorms on a day where returns went from light to extreme in less than
ten minutes.

Granted that the pilot was VFR so presumably he was seeing and avoiding using
the outside picture primarily. But this day it was a typical northeast US
hazy and humid day with visibility around the 6 to 8 mile range, so having
the Garmin 396 for strategic avoidance was a good thing. It still made me
sweat from the comfort of my office chair to imagine that this pilot was
flying through the weather line using up to 8 minute old data (not even
considering the NEXRAD delay before the picture is uplinked to the XM
satellites) and declining the more real-time weather guidance offered by ATC
(SYR approach has excellent weather radar).

Eventually a thunderstorm cell erupted right over the airport, resulting in
numerous wind shear alerts and at least one microburst alert, so the pilot
called approach to state his intention of diverting southeast towards an
airport 50 nm south of SYR to wait out the weather.

--
Peter

Hello:

Eventually we are going to see/read about a pretty "fantastic"
accident with this kind of flying. I've done a reasonable amount of
"line" running in everything from Boeings to TriChamps (although the
latter is much more entertaining since the speed of advance of the
thurderstoms and airplane are closley matched!) with a fairly wide
range of equipment (Radar to STorm Scopes to the XM). MOST of it was
perfectly safe, there were one or two times a few years ago that I had
some "unpleasantries" occur that were fortunatly learning lessons...

But just from the blow by blow you give this pilot strikes me as not
being very clear about what he/she was doing. As you make clear, the
big deal with the XM is the delay...and in a cell/cells where
"training" is taking place that delay can be deadly.

What is fairly scary (at least to me) is that the pilot did not seem
to understand the limitations of his equipment and/or the advantages/
limitations of the ATC radar. If Syracuse has an ASR11/12 then they
have pretty good wx information. It isnt Nexrad but it is certianly
better and more real time then what the XM is showing. Visually you
can spot the "training" and this guy was VFR so that showed some
smarts...but it is not a far leap to when someone is doing this IFR
and finds that the "red" has moved to right where they are...and the
airplane they are flying is now testing the limits of structural
integrity.

the problem with all this new instrumentation is the same as pilots
found when they moved from the classic 737 into the EFIS versions (or
into complete EFIS airplanes)...the training was not up to the
standards of the equipment and people got into severe trouble.

I think that your instincts are pretty good here.

Robert