GPS Nearest Airport feature

[Chris W]

I was flying over Colorado in FS 2004 the other day and was thinking, if
this were a real plane and I were too loose power, what would really be
nice would to have the GPS tell me which of the airports had the
steepest glide to get to it. It would be trivial to have a feature like
that. Do any of the GPS units on the market have such a feature?

--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com

[Peter Duniho]

"Chris W" > wrote in message
news:LG2Vd.70$Ci7.38@lakeread07...
>I was flying over Colorado in FS 2004 the other day and was thinking, if
>this were a real plane and I were too loose power, what would really be
>nice would to have the GPS tell me which of the airports had the steepest
>glide to get to it. It would be trivial to have a feature like that. Do
>any of the GPS units on the market have such a feature?

I've never heard of an aviation GPS that did NOT have a "nearest airport"
feature. The simulated GPS in MSFS should have that feature as well.

AnywhereMap (I think) has something they call "safety cones" (or something
like that) where they graphically portray volumes from within which you can
glide to a given airport.

Pete

[Bravo8500]

They all have nearest, but I've never seen one with steepest descent.
It may not be so trivial to provide steepest descent with no
obstructions on the path.

[Scott D.]

On 1 Mar 2005 11:03:36 -0800, "Bravo8500" >
wrote:

>They all have nearest, but I've never seen one with steepest descent.
>It may not be so trivial to provide steepest descent with no
>obstructions on the path.


But, as the OP stated, he was flying in Colorado. Being based out of
Colorado, that "nearest" feature may not be your saviour. The nearest
airport maybe on the other side of that mountain. So if you have lost
power, you may not be able to make it over that mountain to get to
that airport. So it is always best to know where you are and where
your outs are. We are constantaly playing the "what if" game when we
cross over the range. I want to know, not only where the nearest
airport is, but the nearest VFR airport, the valleys and the lowest
terrain. Hopefully, we leave nothing to chance while we are in the
mountains.


Scott D

To email remove spamcatcher

[Robert M. Gary]

They all do. However, it is based on distance and runway length, not
"steepest glide". I'm not sure why you would want the steepest glide.
Don't you want to use your best glide speed and go to the nearest
airport? I guess the steepest glide would be straight down.

-Robert, Flight Instructor

[Bravo8500]

I think he means if he's flying over a plateau, with an airport on top
of the plateau say 5 miles away, but over the edge of the plateau,
there's one 7 miles away, and 4000 feet lower in elevation since it's
down in the valley or something. If you can make the cliff edge, you've
got 4000 more to drop.

[Lakeview Bill]

Reminds me of a story a friend of mine told me about..

A few years ago, he was taking some sort of check ride, and was asked where
he would land if he had an engine out.

He proudly pointed out a cotton field, an interstate highway, and several
other locations.

The check pilot told him that was very good, and asked him what was wrong
with the airport that was right under them.

My buddy looked out the window, and there was a beautiful little airport
right below.

Needless to say, from then on he always flew with a sectional and a plotter
on his lap...



<Scott D.> wrote in message
...
> On 1 Mar 2005 11:03:36 -0800, "Bravo8500" >
> wrote:
>
> >They all have nearest, but I've never seen one with steepest descent.
> >It may not be so trivial to provide steepest descent with no
> >obstructions on the path.
>
>
> But, as the OP stated, he was flying in Colorado. Being based out of
> Colorado, that "nearest" feature may not be your saviour. The nearest
> airport maybe on the other side of that mountain. So if you have lost
> power, you may not be able to make it over that mountain to get to
> that airport. So it is always best to know where you are and where
> your outs are. We are constantaly playing the "what if" game when we
> cross over the range. I want to know, not only where the nearest
> airport is, but the nearest VFR airport, the valleys and the lowest
> terrain. Hopefully, we leave nothing to chance while we are in the
> mountains.
>
>
> Scott D
>
> To email remove spamcatcher

[Chris W]

Robert M. Gary wrote:

>They all do. However, it is based on distance and runway length, not
>"steepest glide". I'm not sure why you would want the steepest glide.
>Don't you want to use your best glide speed and go to the nearest
>airport? I guess the steepest glide would be straight down.
>
>
I guess I wasn't very clear in my first post. I know they all have the
nearest airport feature and give runway length. Lets say that I am
flying along at 14,000ft and the engine starts doing bad things. Since
I was stupid and wasn't paying attention, I ask my GPS where the nearest
airport is. It tells me that there is an airport 5 knots to my left and
10 knots to my right. What it didn't tell me is the runway to the left
was at an elevation of 10,000ft and the runway to the right was at an
elevation of 5,000ft. Lets make the math simple and pretend there are
6000ft in a nautical mile. To make the airport on the left you would
have to maintain a glide ratio of 7.5 to 1. To make the airport on the
right you would need to maintain a glide ratio of about 6.7 to.
Obviously the runway to the right gives you more room to maneuver. This
is of course assuming there are no obstructions in your path. As
another poster pointed out, if you are flying over the rockies you
better always have a plan on where you are going to go if your loose
power, you are just asking for something bad to happen.

Even from a single simulated flight over Colorado, it's pretty clear to
me, careful planing should go into any such flight in real life.

--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com

[Stefan]

http://www.winpilot.com/

Stefan

[[email protected]]

In article <pu6Vd.84$Ci7.63@lakeread07>, Chris W > wrote:
>Robert M. Gary wrote:
>
>>They all do. However, it is based on distance and runway length, not
>>"steepest glide". I'm not sure why you would want the steepest glide.
>>Don't you want to use your best glide speed and go to the nearest
>>airport? I guess the steepest glide would be straight down.
>>
>>
>I guess I wasn't very clear in my first post. I know they all have the
>nearest airport feature and give runway length. Lets say that I am
>flying along at 14,000ft and the engine starts doing bad things. Since
>I was stupid and wasn't paying attention, I ask my GPS where the nearest
>airport is. It tells me that there is an airport 5 knots to my left and
>10 knots to my right. What it didn't tell me is the runway to the left
>was at an elevation of 10,000ft and the runway to the right was at an
>elevation of 5,000ft. Lets make the math simple and pretend there are
>6000ft in a nautical mile. To make the airport on the left you would
>have to maintain a glide ratio of 7.5 to 1. To make the airport on the
>right you would need to maintain a glide ratio of about 6.7 to.

One thing the GPS can't tell you is the wind speed. This could make a huge
difference whethe you would make an airport or not.
tom

[Cockpit Colin]

"Bravo8500" > wrote in message
ups.com...
> They all have nearest, but I've never seen one with steepest descent.
> It may not be so trivial to provide steepest descent with no
> obstructions on the path.

And if you take wind into account then the aircraft may well glide "more
steeply" towards an airport that's not the initial "first pick" of the GPS.

Perhaps a better option is to have the current glide ratios and glide ration
to target get up on an 'emergency options' configured page of the GPS?

[Cockpit Colin]

Slightly OT, but what I would really LOVE to see is a GPS selectable field
that gives me a bearing FROM a reference, instead of TO one.

ie being able to see at a glance what radial you are crossing/tracking
without having to do the 180 degree mental conversion.

[Robert M. Gary]

Hopefully it wouldn't pick an airport above you! :)

[George Patterson]

Chris W wrote:
>
> It tells me that there is an airport 5 knots to my left and
> 10 knots to my right. What it didn't tell me is the runway to the left
> was at an elevation of 10,000ft and the runway to the right was at an
> elevation of 5,000ft.

You sure? My old LORAN used to provide field elevations, radio frequencies, and
other data for the airports listed in the "nearest" feature. I'd be surprised to
learn aviation GPS units don't do as well.

My LORAN didn't provide the glide ratio data you want, though.

George Patterson
I prefer Heaven for climate but Hell for company.

[George Patterson]

"Robert M. Gary" wrote:
>
> Hopefully it wouldn't pick an airport above you! :)

The "nearest airport" feature of GPS and LORAN units will happily list airports
above you. They have no reason to exclude them. They don't know the rubber band
just broke.

What you want is a "gimme all the airports I can glide to" feature; not "nearest
airport".

George Patterson
I prefer Heaven for climate but Hell for company.

[Jon Woellhaf]

"Cockpit Colin" wrote, "... what I would really LOVE to see is a GPS
selectable field that gives me a bearing FROM a reference, instead of TO
one."

The Garmin GPSMAP 296 does that -- at least for the nearest airport, VOR,
NDB, Intersection,City, or Waypoint (your choice). I have mine set to
nearest VOR. Right now, for example, it says "From Jeffco VOR (BJC): 8.9 nm
S 162°m." This makes it a snap to report position.

Jon

[Peter Duniho]

"Bravo8500" > wrote in message
ups.com...
> They all have nearest, but I've never seen one with steepest descent.

Huh? The steepest descent is the nearest airport. Even in mountainous
terrain, it's incredibly rare to find an airport uphill.

> It may not be so trivial to provide steepest descent with no
> obstructions on the path.

The original poster didn't stipulate "with no obstructions on the path".

I don't think the original question was intended to be nearly as
sophisticated and complicated as you seem to be making it.

Pete

[Peter Duniho]

"Chris W" > wrote in message
news:pu6Vd.84$Ci7.63@lakeread07...
> I guess I wasn't very clear in my first post.

Nope. :)

> I know they all have the nearest airport feature and give runway length.
> Lets say that I am flying along at 14,000ft and the engine starts doing
> bad things. Since I was stupid and wasn't paying attention, I ask my GPS
> where the nearest airport is. It tells me that there is an airport 5
> knots to my left and 10 knots to my right.

You mean "nautical miles"? "Knots" is a measure of speed, not distance.

> What it didn't tell me is the runway to the left was at an elevation of
> 10,000ft and the runway to the right was at an elevation of 5,000ft.

There aren't many airports around at 10,000'. And in mountainous terrain,
airports are usually (though not always, granted) found in the valley
floors. Terrain between you and a lower-altitude airport is probably more
likely to be a problem than a significant difference in altitude between two
choices.

> Lets make the math simple and pretend there are 6000ft in a nautical mile.
> To make the airport on the left you would have to maintain a glide ratio
> of 7.5 to 1. To make the airport on the right you would need to maintain
> a glide ratio of about 6.7 to.

So you actually want the least steep descent, not the steepest descent.

> Obviously the runway to the right gives you more room to maneuver. This
> is of course assuming there are no obstructions in your path. As another
> poster pointed out, if you are flying over the rockies you better always
> have a plan on where you are going to go if your loose power, you are just
> asking for something bad to happen.

Now, you've written "loose" twice. It's "lose". I only "loose power"
during takeoffs and climbs. :)

> Even from a single simulated flight over Colorado, it's pretty clear to
> me, careful planing should go into any such flight in real life.

Indeed. That said, as I mentioned, there's at least one product out there
that displays 3D volumes (cones) to aid you in the exact decision making
you're asking about. Since your position relative to the cone depends not
only on your lateral distance, but your altitude above the airport as well,
it gives you the information you're thinking of. (Actually, while the data
is 3D, I believe it simply shows you a 2D cross-section of the cone on your
top-down map display)

That particular feature is not common though (only on one GPS navigation
unit that I'm aware of). I'm honestly not convinced it's really all that
necessary or useful except in very rare instances.

Pete

[Peter Duniho]

"Cockpit Colin" > wrote in message
...
> Slightly OT, but what I would really LOVE to see is a GPS selectable field
> that gives me a bearing FROM a reference, instead of TO one.

My Loran will do that. It would surprise me if GPS units didn't generally
allow that.

[Cockpit Colin]

Gawd Dang - and I've got a 296 as well!

Thanks for the heads up - I'll have to check it out. To be honest, I very
seldom use the 'nearest' function - I mostly just configue the first page
with timers / gps state - the 2nd with enroute infor - and the 3rd for
approach related stuff. Would still be nice to be able to have something
like a BGF (BearingG From) field though.

Cheers,

CC


"Jon Woellhaf" > wrote in message
...
> "Cockpit Colin" wrote, "... what I would really LOVE to see is a GPS
> selectable field that gives me a bearing FROM a reference, instead of TO
> one."
>
> The Garmin GPSMAP 296 does that -- at least for the nearest airport, VOR,
> NDB, Intersection,City, or Waypoint (your choice). I have mine set to
> nearest VOR. Right now, for example, it says "From Jeffco VOR (BJC): 8.9
nm
> S 162°m." This makes it a snap to report position.
>
> Jon
>
>

[Cockpit Colin]

I was surprised too - it seemed to me that the whole GPS mentality is about
where you're positioned with respest to where you're going, not where you've
been. Sometimes when you're out over "the back hills" you're not close
enough to a visual reporting point to be able to give the tower a report
that's accurate enough for seperation purposes - would be nicer to be able
to say "Crossing the GPS equivalent of your 272 radial at 18 XXX DME"



"Peter Duniho" > wrote in message
...
> "Cockpit Colin" > wrote in message
> ...
> > Slightly OT, but what I would really LOVE to see is a GPS selectable
field
> > that gives me a bearing FROM a reference, instead of TO one.
>
> My Loran will do that. It would surprise me if GPS units didn't generally
> allow that.
>
>

[Cockpit Colin]

Ummm ...

Having checked it out my 296 on the NRST screen shows bearing and distance
TO (not from).

Are we talking about the same function here, or are you looking in a
different area?

Thanks

CC



"Cockpit Colin" > wrote in message
...
> Gawd Dang - and I've got a 296 as well!
>
> Thanks for the heads up - I'll have to check it out. To be honest, I very
> seldom use the 'nearest' function - I mostly just configue the first page
> with timers / gps state - the 2nd with enroute infor - and the 3rd for
> approach related stuff. Would still be nice to be able to have something
> like a BGF (BearingG From) field though.
>
> Cheers,
>
> CC
>
>
> "Jon Woellhaf" > wrote in message
> ...
> > "Cockpit Colin" wrote, "... what I would really LOVE to see is a GPS
> > selectable field that gives me a bearing FROM a reference, instead of TO
> > one."
> >
> > The Garmin GPSMAP 296 does that -- at least for the nearest airport,
VOR,
> > NDB, Intersection,City, or Waypoint (your choice). I have mine set to
> > nearest VOR. Right now, for example, it says "From Jeffco VOR (BJC): 8.9
> nm
> > S 162°m." This makes it a snap to report position.
> >
> > Jon
> >
> >
>
>

[Jon Woellhaf]

Hi, CC.

I thought I may have confused you.

The field to which I'm referring isn't on the page accessed by pushing the
NRST button.

It's on what Garmin calls the "Position Data Page." In Aviation mode, that's
the one you reach from the Map page by pressing Quit once. The field in
question only appears when this page is configured for "2 Columns (Small)."
In this configuration, the ten fields on the right-hand half of the page are
changed in the usual manner. The left-hand half of the screen has four
fixed-type data fields. The bottom one is the "Nearest" field we're talking
about. Push Menu and select Change Nearest Type to configure this field as I
described.

Regards,

Jon

"Cockpit Colin" > wrote in message
...
> Ummm ...
>
> Having checked it out my 296 on the NRST screen shows bearing and distance
> TO (not from).
>
> Are we talking about the same function here, or are you looking in a
> different area?
>
> Thanks
>
> CC
>
>
>
> "Cockpit Colin" > wrote in message
> ...
>> Gawd Dang - and I've got a 296 as well!
>>
>> Thanks for the heads up - I'll have to check it out. To be honest, I very
>> seldom use the 'nearest' function - I mostly just configue the first page
>> with timers / gps state - the 2nd with enroute infor - and the 3rd for
>> approach related stuff. Would still be nice to be able to have something
>> like a BGF (BearingG From) field though.
>>
>> Cheers,
>>
>> CC
>>
>>
>> "Jon Woellhaf" > wrote in message
>> ...
>> > "Cockpit Colin" wrote, "... what I would really LOVE to see is a GPS
>> > selectable field that gives me a bearing FROM a reference, instead of
>> > TO
>> > one."
>> >
>> > The Garmin GPSMAP 296 does that -- at least for the nearest airport,
> VOR,
>> > NDB, Intersection,City, or Waypoint (your choice). I have mine set to
>> > nearest VOR. Right now, for example, it says "From Jeffco VOR (BJC):
>> > 8.9
>> nm
>> > S 162°m." This makes it a snap to report position.
>> >
>> > Jon
>> >
>> >
>>
>>
>
>

[Bravo8500]

Steepest ... An airport right under you would be about the steepest. If
I could choose between an airport 1000 feet below me and 5 miles away,
and another 7000 below me and also 5 miles away, the lower airport has
the steeper descent.

[Cockpit Colin]

Thanks Jon - now that you mention it I have seen the field before - the
"penny never quite dropped" though.

Thanks for that.

I suggested it to Garmin several years ago and got a "thank you for
contacting garmin - thank you for your suggestion - many improvements come
about because of people like you etc" response - then when the 296 came out
I suggested it again - and got the exact same eMail.

Trying to get any action out of Garmin is like mating elephants :(

Cheers,

CC

"Jon Woellhaf" > wrote in message
...
> Hi, CC.
>
> I thought I may have confused you.
>
> The field to which I'm referring isn't on the page accessed by pushing the
> NRST button.
>
> It's on what Garmin calls the "Position Data Page." In Aviation mode,
that's
> the one you reach from the Map page by pressing Quit once. The field in
> question only appears when this page is configured for "2 Columns
(Small)."
> In this configuration, the ten fields on the right-hand half of the page
are
> changed in the usual manner. The left-hand half of the screen has four
> fixed-type data fields. The bottom one is the "Nearest" field we're
talking
> about. Push Menu and select Change Nearest Type to configure this field as
I
> described.
>
> Regards,
>
> Jon
>
> "Cockpit Colin" > wrote in message
> ...
> > Ummm ...
> >
> > Having checked it out my 296 on the NRST screen shows bearing and
distance
> > TO (not from).
> >
> > Are we talking about the same function here, or are you looking in a
> > different area?
> >
> > Thanks
> >
> > CC
> >
> >
> >
> > "Cockpit Colin" > wrote in message
> > ...
> >> Gawd Dang - and I've got a 296 as well!
> >>
> >> Thanks for the heads up - I'll have to check it out. To be honest, I
very
> >> seldom use the 'nearest' function - I mostly just configue the first
page
> >> with timers / gps state - the 2nd with enroute infor - and the 3rd for
> >> approach related stuff. Would still be nice to be able to have
something
> >> like a BGF (BearingG From) field though.
> >>
> >> Cheers,
> >>
> >> CC
> >>
> >>
> >> "Jon Woellhaf" > wrote in message
> >> ...
> >> > "Cockpit Colin" wrote, "... what I would really LOVE to see is a GPS
> >> > selectable field that gives me a bearing FROM a reference, instead of
> >> > TO
> >> > one."
> >> >
> >> > The Garmin GPSMAP 296 does that -- at least for the nearest airport,
> > VOR,
> >> > NDB, Intersection,City, or Waypoint (your choice). I have mine set to
> >> > nearest VOR. Right now, for example, it says "From Jeffco VOR (BJC):
> >> > 8.9
> >> nm
> >> > S 162°m." This makes it a snap to report position.
> >> >
> >> > Jon
> >> >
> >> >
> >>
> >>
> >
> >
>
>

[Jeff Shirton]

"Peter Duniho" > wrote in message
...
> "Chris W" > wrote in message
> news:pu6Vd.84$Ci7.63@lakeread07...

>> where the nearest airport is. It tells me that there is an airport 5
>> knots to my left and 10 knots to my right.
>
> You mean "nautical miles"? "Knots" is a measure of speed, not distance.

Maybe the "airports" were on aircraft carriers?
That would work... <g>

>> have a plan on where you are going to go if your loose power, you are
>> just asking for something bad to happen.
>
> Now, you've written "loose" twice. It's "lose". I only "loose power"
> during takeoffs and climbs. :)

Yeah, I noticed that too...

I also noticed that "loose" is active, while "lose" is passive...
<g>

> Pete

--
Jeff Shirton jshirton at cogeco dot
ca
<><><><><><><><><><><><><><><><><><><><><><><>
Keep thy airspeed up, lest the earth come from below
and smite thee. - William Kershner
Challenge me (Theophilus) for a game of chess at Chessworld.net!