Marine Radar in a plane?

On Mon, 11 Aug 2003 17:09:41 -0700, pac plyer wrote:

(Ross Oliver) wrote
I have always heard that a lightning detector such as StrikeFinder or
Stormscope works just as well as radar for thunderstorm avoidance,

You've heard way wrong.

Bob Moore
ATP B-727 B-707 L-188
FI ASE/IA
USN S-2F P-2V B-3B
PanAm (retired)

Man you said it Bob. Twice out in the South Pacific with convective wx,
ops tried to get me to fly the trip without any radar. My response was
the same both times: If you can't fix it, just give us a call at the
hotel, cuz that's were we'll be until you break out the bucks to go buy
one from Singapore Airlines or somebody and fly it on over here. (some
of those Equatorial boomers go up to 70,000 ft) I'm just too ****ing
cute to die anymore.

pacplyer
ex-thunderstorm nafod

pacflyer - which aircraft do you have your StormScope or StrikeFinder time
on? Have you flown any GA radars?

I've flown both StormScopes and WX radar (I don't have any time on cheap
GA radar though), and one of my current aircraft actually has both. You
need to understand that the two technologies have different limitations.
Radar does a good job of finding water, and pretty much any thunderstorm
worth worrying about will be dumping lots of water. But, you need to
understand how to work the tilt knob, and you need to understand that just
because that glob of red looks pretty thin doesn't mean it is a good place
to try to punch through. If the water is coming down strong enough, it
will stop the radar from seeing anything further out in that direction. So
you may see a glob of red, with green and black on the other side, but it
is only green or black because the radar signal isn't punching through to
there.

The StormScope stuff, in theory, should keep you out of the really bad
stuff, as any CB should be producing lightening. It won't keep you out of
TCUs, but they shouldn't kill you, although they may scare the hell out of
you. I've seen quite a bit of variation in performance on different
StormScope installations. One aircraft I flew (TB-21) had a StormScope
installation that worked extremely well. The C550s that I fly with
StormScope seem to work much less well. I suspect the technology is very
sensitive to where the antenna is located, how well everything is
grounded, and how much electrical noise the aircraft produces. YMMV.

With weather radar, I suspect there is probably less installation to
installation difference in performance, for the same model unit and same
antenna. Obviously more expensive units with bigger antennae and more
power will work better than the cheaper GA stuff.

If I was spending my money, I'd take a StormScope over a cheap radar. But
I would do a lot of testing in VMC with CBs in the area to satisfy myself
that it was working properly before I went into clouds with it. If I was
spending my boss's money, I'd take an expensive radar over a StormScope.

--
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://go.phpwebhosting.com/~khorton/rv8/

Kevin Horton wrote snip

pacflyer - which aircraft do you have your StormScope or StrikeFinder time
on? Have you flown any GA radars? snip

Kev, For me it's been all Wx Radar. BE-18 had an old-timey (RCA I
believe?) set that was broken most all of the time. All of my other
experience has been with numerous different commercial sets in jets:
Bendix, Collins, RCA, etc. Lots of the guys I flew with at four
airlines however, flew Stormscope stuff in GA. None of them
has ever said anything good about it. In fact most of them say these
exact words when asked: "it's better than nothing." Unquote. After an
old hand like me teaches em how to set the gain manually and put a
little ground clutter out there with the tilt for insurance they don't
want to go back. Approaching a line? Use the tilt formula to
calculate if the cell is above your altitude or not. Doubt you can
tell much about vertical development with a Stormsope but then I've
never used one; been spoiled with good radar. The newer Collins sets
have auto-tilt and gggreat turb modes (magenta) but no one has been
able to explain to me how this feature works even in clear air. It's
amazing. And I'm a guy who used to fly into IAH every night in
occluded fronts, windshear, downbursts etc on an old Bendix green
screen (and I thought that was great.)

How's the weather?

We used to say: "what difference does it make? we're going anyway!"


snip
.. If the water is coming down strong enough, it
will stop the radar from seeing anything further out in that direction. So
you may see a glob of red, with green and black on the other side, but it
is only green or black because the radar signal isn't punching through to
there.

Yes indeed. This is called attenuation (actually the radar probably
does make it to the curved edges of the drops in your downburst or
strong cell, its just that the energy is absorbed or deflected and
never makes it back to the aircrafts' antenna receiver dish.) This
killed the crew and occupants of a NWA flight one night. They punched
into a level five I think we would call that today. This was a
famous accident in the industry and one night I was jumpseating on AWA
to JFK and we watched another flight below us try to do the same thing
over Kansas City. A huge discharge that blinded us for a second
convinced him to turn around. He kept arguing with ATC about how good
it looked straight ahead. We were all laughing our asses off when we
saw him do the 180!

The StormScope stuff, in theory, should keep you out of the really bad
stuff, as any CB should be producing lightening. It won't keep you out of
TCUs, but they shouldn't kill you, although they may scare the hell out of
you. I've seen quite a bit of variation in performance on different
StormScope installations. One aircraft I flew (TB-21) had a StormScope
installation that worked extremely well. The C550s that I fly with
StormScope seem to work much less well. I suspect the technology is very
sensitive to where the antenna is located, how well everything is
grounded, and how much electrical noise the aircraft produces. YMMV.

With weather radar, I suspect there is probably less installation to
installation difference in performance, for the same model unit and same
antenna. Obviously more expensive units with bigger antennae and more
power will work better than the cheaper GA stuff.

Radome cleanliness is important with big commercial units. I've lost
ability to paint targets due to extreme ice built up on the nose in
flight, and due to peeling paint. Peeling paint is the worst. You
constantly are dodging phantom cells that aren't there. We cringe at
the thought of no radar, but truthfully, a lot of the old guys flew
Connies without any and weren't concerned about it. They were
*always* in the weather they told me. Of course several disappeared
and were never found.

Ahhh ... constant turbulence that spills my coffie on my white shirt
and the faint smell of burning glycol in the packs and the
acrid odor of negative ions at high altitude, combined with bone-dry
eyeballs and radioactive, infectious, packages just inches from the
meal storage box.... makes me want to be scud-running in my little
airplane with a strike finder!

Stay away from Freddie Kilowatt!

pacplyer - out