SN-10 vs CAI 302

Kilo Charlie wrote:
wrote in message
ups.com...

Interesting since the SN-10 has an entire page devoted to nothing but
closest/nearest landing points. It allows you to order them wrt nearest or
an easy scroll through names for one that you may know you would rather land
at. I use it frequently during racing or other XC and rarely use the map.
It automatically gives distances to the fields and considers the current
winds and Mc setting and also puts in a 150 meter arrival altitude along
with displaying how far over or under a glide to the field you are. I don't
see how something could be much easier to use than that.

Does it include terrain obstructions as well?

Jeremy

I fly with a 1530 and GN II.
I do not have to turn to a different page. The airports and out
landing
fields are displayed at all times. If I have a need for an out
landing
port or field I touch the port on the screen and all relevant info is
displayed,
about that port, including the final glide. I like the one screen one
page display.
Udo






Interesting since the SN-10 has an entire page devoted to nothing but
closest/nearest landing points. It allows you to order them wrt nearest or
an easy scroll through names for one that you may know you would rather land
at. I use it frequently during racing or other XC and rarely use the map.
It automatically gives distances to the fields and considers the current
winds and Mc setting and also puts in a 150 meter arrival altitude along
with displaying how far over or under a glide to the field you are. I don't
see how something could be much easier to use than that.

Casey Lenox
KC
Phoenix

"Jeremy Zawodny" wrote in message
...

Does it include terrain obstructions as well?

Jeremy

No but I've always found those quite interesting in concept for glider
pilots.....if you are talking about making it around a mountain on the way
home I'd rather be looking out the window at what's in front of me and not
relying upon an instrument to tell me its there.....head in vs out of the
cockpit idea I guess. Otherwise I can think of nothing that having a moving
map of terrain does to assist me in flying my glider in VFR conditions.

Casey

Kilo Charlie wrote:
"Jeremy Zawodny" wrote in message
...

Does it include terrain obstructions as well?

Jeremy

No but I've always found those quite interesting in concept for glider
pilots.....if you are talking about making it around a mountain on the way
home I'd rather be looking out the window at what's in front of me and not
relying upon an instrument to tell me its there.....head in vs out of the
cockpit idea I guess. Otherwise I can think of nothing that having a moving
map

When I fly in the mountains, I find the "obstructions" feature and the
terrain map on SeeYou Mobile quite useful, because looking out the
window towards a landing place I can't see doesn't help me. I know the
mountain(s) is there (that's the usual reason I can't see the landing
place, besides distance), but "can I clear it" isn't something I can
eyeball reliably. The nearest mountain might not be the one that is
blocking me, for example.

Flat lands, low hills, or areas I am totally familiar with - the terrain
feature is of no use to me.

--
Eric Greenwell - Washington State, USA
Change "netto" to "net" to email me directly

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Eric Greenwell wrote:
Kilo Charlie wrote:
"Jeremy Zawodny" wrote in message
...

Does it include terrain obstructions as well?

Jeremy

No but I've always found those quite interesting in concept for glider
pilots.....if you are talking about making it around a mountain on the
way home I'd rather be looking out the window at what's in front of me
and not relying upon an instrument to tell me its there.....head in vs
out of the cockpit idea I guess. Otherwise I can think of nothing
that having a moving map

When I fly in the mountains, I find the "obstructions" feature and the
terrain map on SeeYou Mobile quite useful, because looking out the
window towards a landing place I can't see doesn't help me. I know the
mountain(s) is there (that's the usual reason I can't see the landing
place, besides distance), but "can I clear it" isn't something I can
eyeball reliably. The nearest mountain might not be the one that is
blocking me, for example.

Exactly.

On one flight this summer I found myself a bit north of Spooner Lake
trying to decide if I could clear Brockway Pass and make Truckee. I
decided to go for it and after a few miles noticed that SeeYou was
warning me that I'd impact terrain on the way.

Of course, it didn't know that I planned to divert a bit, since the
straight course isn't over the lowest point. But I sure was glad to
know it was thinking of me. :-)

Jeremy

"Jeremy Zawodny" wrote in message
...
Eric Greenwell wrote:
Kilo Charlie wrote:
"Jeremy Zawodny" wrote in message
...

Does it include terrain obstructions as well?

Jeremy

No but I've always found those quite interesting in concept for glider
pilots.....if you are talking about making it around a mountain on the
way home I'd rather be looking out the window at what's in front of me
and not relying upon an instrument to tell me its there.....head in vs
out of the cockpit idea I guess. Otherwise I can think of nothing that
having a moving map

When I fly in the mountains, I find the "obstructions" feature and the
terrain map on SeeYou Mobile quite useful, because looking out the window
towards a landing place I can't see doesn't help me. I know the
mountain(s) is there (that's the usual reason I can't see the landing
place, besides distance), but "can I clear it" isn't something I can
eyeball reliably. The nearest mountain might not be the one that is
blocking me, for example.

Exactly.

On one flight this summer I found myself a bit north of Spooner Lake
trying to decide if I could clear Brockway Pass and make Truckee. I
decided to go for it and after a few miles noticed that SeeYou was warning
me that I'd impact terrain on the way.

Of course, it didn't know that I planned to divert a bit, since the
straight course isn't over the lowest point. But I sure was glad to know
it was thinking of me. :-)

Jeremy

Maybe we're mixing things up a bit. I agree that knowing if I can make a
glide into a landable place is a good thing and the SN-10 does that. I
would still say given that, you should be looking outside to see what
mountains you need to go around in order to get there is a better idea than
looking at an instrument heads down. Also I would not find the instrument
much help unless it could calculate the required deviation from my current
position around the mountain then home. At least for me I would not want to
leave my margins flying in the mountains so thin that I could just clear a
pass.

Finally all of the instrument manufacturers that feature terrain maps state
emphatically that they should NOT be used as terrain avoidance instruments.
My guess is that is due to the inaccuracies of the terrain altitude data.
I'm not willing to bet my life on that.

Casey

Flying in mountains I select the next potential landing site quite often
when 50km or more away from the site. For this it is quite helpful to
have the terrain avoidance feature, to select only sites where I don't
have to tunnel through a mountain range.

When I select the next potential landing site, which might be still 50
km away, I might be already below the rims of the surrounding mountain
ranges.


Kilo Charlie schrieb:
"Jeremy Zawodny" wrote in message
...
Eric Greenwell wrote:
Kilo Charlie wrote:
"Jeremy Zawodny" wrote in message
...

Does it include terrain obstructions as well?

Jeremy
No but I've always found those quite interesting in concept for glider
pilots.....if you are talking about making it around a mountain on the
way home I'd rather be looking out the window at what's in front of me
and not relying upon an instrument to tell me its there.....head in vs
out of the cockpit idea I guess. Otherwise I can think of nothing that
having a moving map
When I fly in the mountains, I find the "obstructions" feature and the
terrain map on SeeYou Mobile quite useful, because looking out the window
towards a landing place I can't see doesn't help me. I know the
mountain(s) is there (that's the usual reason I can't see the landing
place, besides distance), but "can I clear it" isn't something I can
eyeball reliably. The nearest mountain might not be the one that is
blocking me, for example.
Exactly.

On one flight this summer I found myself a bit north of Spooner Lake
trying to decide if I could clear Brockway Pass and make Truckee. I
decided to go for it and after a few miles noticed that SeeYou was warning
me that I'd impact terrain on the way.

Of course, it didn't know that I planned to divert a bit, since the
straight course isn't over the lowest point. But I sure was glad to know
it was thinking of me. :-)

Jeremy

Maybe we're mixing things up a bit. I agree that knowing if I can make a
glide into a landable place is a good thing and the SN-10 does that. I
would still say given that, you should be looking outside to see what
mountains you need to go around in order to get there is a better idea than
looking at an instrument heads down. Also I would not find the instrument
much help unless it could calculate the required deviation from my current
position around the mountain then home. At least for me I would not want to
leave my margins flying in the mountains so thin that I could just clear a
pass.

Finally all of the instrument manufacturers that feature terrain maps state
emphatically that they should NOT be used as terrain avoidance instruments.
My guess is that is due to the inaccuracies of the terrain altitude data.
I'm not willing to bet my life on that.

Casey

Kilo Charlie wrote:

Maybe we're mixing things up a bit. I agree that knowing if I can make a
glide into a landable place is a good thing and the SN-10 does that. I
would still say given that, you should be looking outside to see what
mountains you need to go around in order to get there is a better idea than
looking at an instrument heads down.

The terrain warning doesn't require you to stare at the PDA, anymore the
Ilec requires you to stare at it. Just glance at it, see the red square
indicating the place where your glide slope is too low, and by how much.
Go back to looking out the window while you decide how to get around or
over the obstacle.

Also I would not find the instrument
much help unless it could calculate the required deviation from my current
position around the mountain then home.

That would be ideal, and I've suggested it to SeeYou, but it's not been
implemented. Maybe the next release. In the meantime, I've found the
warning is more useful than no warning.

At least for me I would not want to
leave my margins flying in the mountains so thin that I could just clear a
pass.

SeeYou uses a "clearance" altitude above the ridge equal to the
"arrival" height chosen for getting to a landing place. I usually use
1000 feet. So, when the red square first appears, it means my projected
glide slope is 999 feet above the terrain.

Finally all of the instrument manufacturers that feature terrain maps state
emphatically that they should NOT be used as terrain avoidance instruments.
My guess is that is due to the inaccuracies of the terrain altitude data.
I'm not willing to bet my life on that.

Did anything I said sound like I was flying with my eyes closed? The
pilot must use his judgement about reaching a landing place, whether
there is a mountain between it or not. I'm sure you don't head for a
landing place over a national forest at a zero McCready setting, just
because the Ilec says you are 50 feet above glide slope. Come on, give
us PDA users some credit.

--
Eric Greenwell - Washington State, USA
Change "netto" to "net" to email me directly

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org

"Eric Greenwell" wrote:

Also I would not find the instrument much help unless it could calculate
the required deviation from my current position around the mountain then
home.

That would be ideal, and I've suggested it to SeeYou, but it's not been
implemented. Maybe the next release. In the meantime, I've found the
warning is more useful than no warning.

GPS-LOG (Freeware!) is once more ahead of its commercial competitors: It can
display an outline of the reachable area taking terrain into account.

Good work Henryk!
Michael

"Eric Greenwell" wrote in message
news:UAG5h.2306$T_.2002@trndny06...
Kilo Charlie wrote:
Did anything I said sound like I was flying with my eyes closed? The pilot
must use his judgement about reaching a landing place, whether there is a
mountain between it or not. I'm sure you don't head for a landing place
over a national forest at a zero McCready setting, just because the Ilec
says you are 50 feet above glide slope. Come on, give us PDA users some
credit.

--
Eric Greenwell - Washington State, USA
Change "netto" to "net" to email me directly

I'm not knocking the "PDA users" Eric. In fact for the record I have a PDA
running SeeYou mobile too as an entirely separate system (in addition to the
SN-10/VL) attached to another VL. I like some of the features of SeeYou but
have found it to be unreliable re altitudes at times. The best way I've
found to keep it within tolerances is to place it in the GPS mode and
unlinked. Do you have a better way of doing it? I haven't noted that
SeeYou gives me clearance heights over terrain but maybe its because I'm
conservative and haven't had it alarm due to that.

Also for the record one of our local pilots was flying in the hills a couple
of years back and did exactly what I stated.....had a Mc zero setting in for
a landable strip and hit huge sink on the way there causing him to have to
land in a very bad area.....large paloverdes and cactus. He was very lucky
to walk away unhurt. The glider was a mess but repairable.

Here in AZ we have encountered some very heavy sink over extended periods in
the mountains and so my point overall is that I would suggest keeping extra
altitude as a safety margin. There are a lot of people that read this
newsgroup and even though some may be a very experienced mountain pilots
others may not be. Squeaking a glide into a strip around mountains sounds
like a setup for problems when hitting bad sink.

Casey