Hello Pilotage-ga,
As a pilot myself, though one who generally flies overland at much
lower altitudes than the oceanic routes, I was intrigued by your
question, and found myself learning quite a bit while researching the
answer.
To begin with, you may be aware that the North Atlantic Track System
(NATS) routes do not stay the same, but are updated twice daily in
order to maximize fuel efficiency based on the position of the
jetstream as well as winds aloft and other weather considerations.
These routes are defined by their entry and exit points, as well as by
a set of waypoints, i.e. lat/long coordinates, enroute, and are flown
at a specific altitude, usually above FL300 (or 30,000 feet). What
this means, of course, is that the waypoints on any of these routes do
not stay the same, but are changeable. If you’d like to read up a bit
on how this all works, here are a couple of sites with some
explanation:
http://www.flywestwind.com/WTC/Pprograms/international.htm
http://bathursted.ccnb.nb.ca/vatcan/fir/VCAF/doc/VATCAN-oceanic-routes.doc
The current naming convention labels the westbound (Europe to North
America) routes “ABC,” etc., and the eastbound (North America to
Europe) “XYZ.” Generally, the eastbound routes are flown at lower
(more southerly) latitudes to take advantage of the west to east winds
aloft influenced by the jetstream, while the westbound routes are
flown at higher (more northerly) latitudes in order to avoid these
winds, which would clearly reduce speed and fuel efficiency. Here are
some maps of NATS routes, both actual (past):
http://natroutes.glideslope.de/images/XYZ.png and theoretical (made up
for a simulator program/virtual airline):
http://www.avsim.com/geoffschool/va/information/atlantictracks.htm
Now, you might see why your hypothetical waypoint, i.e. 55N030W is
more likely to be on a westbound (ABC) route, than on an eastbound
(XYZ) route. However, I suspect that you are using one of the many
simulators or simulation games out there, in which case you may be
making use of the static (unchanging) routes designed for that
purpose. Whether or not you are, you should still be able to determine
possible location(s) of any potential emergency landing site(s) from
that stated position. Bear in mind, however, that the ability to
reach any land will depend on factors other than distance, such as
altitude, airspeed, rate of descent, power availability and others.
The best tool I’ve found for you is located here:
http://natroutes.glideslope.de/ (Btw, there are a lot of other great
tools on this page.) Download the NATPLOT v.1.5 program to your
computer, unzip and run it. It’s a very cool program, showing the
entry and exit points of all the NATs. The best part is, when you run
your mouse over the map, the status bar at the bottom shows the
changing lat/long points to the second. Using that information, it
will be easy to determine the lat/long of the closest land to your
waypoint.
Then, take the two lat/long waypoints, input them into a distance
calculator, and you will find out how far it is between them. This
information, together with the other factors I mentioned previously,
such as altitude and airspeed, will enable you to determine a glide
distance and whether or not you’ll be able to reach land safely.
From a general look-see, it appears that some small islands just off
the southwestern coast of Ireland would be the closest land to your
stated waypoint, followed by other points along the Irish coast,
followed by Iceland, in that order distance-wise. You didn’t mention
wanting an airport, so I didn’t take that into consideration.
Besides, in an emergency, one doesn’t always have that luxury anyway,
though bear in mind a GPS unit will generally have a “Nearest Airport”
button on it, which should work even if you are temporarily out of
reach of radar.
Here are links to two good distance calculators:
http://jan.ucc.nau.edu/~cvm/latlongdist.html
http://www.go.ednet.ns.ca/~larry/bsc/jslatlng.html
Using the above advice, the distance between your waypoint and the
southwestern point of Ireland is 1299 km or about 700 nautical miles.
Here’s a converter that goes between kilometers, nautical miles and
statute miles: http://www.csgnetwork.com/nsmilekmconverter.html
If you’d like to take a close-up look at any areas, I’d suggest just
using Mapquest, which will let you zoom in quite close. Go to this
page: http://www.mapquest.com/maps/latlong.adp , input your
approximate lat/long coordinates (hint: N is +, W is -), zoom in as
far as you can, and see exactly where they put you. Might take a
little juggling to find a reasonable spot.
If you’re interested in a printed resource, and/or the most detailed
information available, I’d suggest you consider purchasing the
official chart depicting these (NAT) routes. Even if you’re using a
sim, this chart is fairly inexpensive at $9.55 (plus s/h), and will
give you the same information as that used by professional pilots and
air traffic controllers. You can buy one here:
http://www.avshop.com/catalog/product.html?productid=1466
Here are some other resources you might like to have a look at:
--Navigator (mapping/map reading) software. There is a freeware
version:
http://www.tecepe.com.br/nav/download.htm
--Free charts to use with Navigator (includes North Atlantic):
http://www.tecepe.com.br/nav/chartlib.htm
--A fantastic site loaded with links to all kinds of resources for
both sim and real world pilots:
http://www.tooby.demon.co.uk/P_Assist_Description.html#ChartsFLightPlanning
I hope this information helps you out. If there’s anything you don’t
understand, please do use the “Request Clarification” feature before
rating and closing the question, so I can be sure I’ve answered it to
your satisfaction. Thank you for the chance to research this very
interesting subject.
Best regards,
Byrd
Search strategy:
"north atlantic" "oceanic route" OR "air route"
NATS OR "north atlantic track system" OR "north atlantic routes"
"north atlantic" maps OR charts OR "aeronautical charts"
free download "north atlantic" maps OR charts
Personal bookmarks for distance calculators and converters |
Clarification of Answer by
byrd-ga
on
12 Sep 2003 09:32 PDT
Hi pilotage-ga!
Wow, an old AT-6? I have a grand total of .6 dual in an AT-6 garnered
a few years ago -- 36 minutes of some of the most fun I’ve ever had in
an airplane! And that’s your usual ride? Wow. I’m truly envious!
Whew. Ahem, that is, all right then, back to the subject in hand ....
First of all, no, I’m sorry, it’s prohibited to post or share personal
information here, and that includes emails. If the editors see that
you’ve posted yours, they may either remove your clarification request
or the entire question, so if you want to save any of the links
provided, I’d suggest you do so in a separate document.
Now then, your question really has me wondering now. I did do some
more searching, but couldn’t come up with any feasible reason why, on
the basis of published routes and procedures, your flight was diverted
to the Azores for an emergency occurring at such a northerly latitude.
That just doesn’t seem to make much sense at all, does it?
The Azores are located approximately 36-39 degrees N and 24-31 degrees
west, so if you diverted from a 55N/30W location, well, that’s a long
way to fly, much farther than to Ireland or any number of other
places. See this map:
http://www.mapquest.com/maps/map.adp?title=Latitude%3A+38%C2%B0+30+Min.0+Sec.%2C+Longitude%3A+-28%C2%B0+0+Min.+0+Sec.%2C+&size=big&style=MEDIUM&point.0.label=&point.0.icon=230&mapdata=1Y6lqyrbdWI355IqDxpKOXU6StTXOjQF%2BHL0wuI4MJDAzFDSMG5qp7SSLqvfNMc5BLHf8oevMoOsdeFIy819Ab%2F5eQZ0kQrVpjXJAwS3agAkRmdCDiNnoeVmKxFoDHnGqQGlLCHjZI%2FZ6GB26Ui1%2FrmqxcziY7%2FsUkF1uKgP4li31F%2BEGK49igyfGJeF%2BeP%2FZ4gU4dvy
%2Fk%2Bn9yrBsmtitTPOBx36pT6dgT62NzMIcsjlxPWw0uRVFK6OSipAyjsQpWxzD%2BBp%2F5ew9yMd%2BFQ%2FeCV4pDqBmzoEUM7r69rHgug9l6vqaRNfdxRDSW%2BHuV3KMdXFaBLfRbQlbXPYihZTiyK%2FTKpQVVZjWNOLGzrn%2FcQT5LSlobYSE9TQiBqlbU6FEifUAFpl91DnCZQ3TTnjxgX0JIq3n7DjbOEqTs8VsKlzNsLzR5JppEQrcEvTY05hw6uYXJAcKLmHzCr26EZ3hVtCNLhRWwOmJPJwpXqe5pFEyWV1U4JfXL%2B%2FXc3vECLcKpvRrPew%2Fq5gufpwlHK7CpKiIl1nR5x%2F2UMz0kABeHiz0e%2FpLDussoi2vVt5
H2&submit.x=22&submit.y=11 (*NOTE: you might need to zoom out a bit),
where the little airplane is right in the middle of the Azores at
38’30”N/28W, much farther south than both your point of diversion AND
your destination.
Here’s a definition of the boundaries of the North Atlantic area for
air navigation (*note: this is from a British document
http://www.hmso.gov.uk/si/si1995/Uksi_19951038_en_20.htm , but since
the UK is a member of ICAO, which oversees international aviation
matters, I’m assuming for this purpose that these area definitions
would apply internationally):
Area H—North Atlantic Ocean
All that area enclosed by rhumb lines joining successively the
following points:
55° north latitude 15° west longitude
68° north latitude 28° west longitude
68° north latitude 60° west longitude
45° north latitude 45° west longitude
40° north latitude 60° west longitude
40° north latitude 19° west longitude
55° north latitude 15° west longitude
So you can see that the Azores fall outside the boundaries of the
North Atlantic area. However, they fall within the boundaries of the
South Atlantic, per se:
Area I—South Atlantic Ocean
All that area enclosed by rhumb lines joining successively the
following points:
40° north latitude 60° west longitude
18° north latitude 60° west longitude
05° south latitude 30° west longitude
55° south latitude 55° west longitude
55° south latitude 10° east longitude
40° south latitude 10° east longitude
02° north latitude 05° east longitude
02° north latitude 10° west longitude
15° north latitude 25° west longitude
40° north latitude 19° west longitude
40° north latitude 60° west longitude
Since a New York to Paris, i.e. JFK-CDG, flight is generally flown
within the boundaries of the North Atlantic area, and would generally
be on a flight plan that included the approximate lat/long you gave,
this is indeed a puzzle. Without actually contacting Delta and
attempting to get information from their flight planning department, I
can only speculate that there must have been some compelling reason
why your flight was diverted from a northerly position to such a
southerly landing zone. The only things that come to mind are 1)since
an electrical problem is not necessarily a time-critical emergency,
perhaps you were sent to a place that had on hand the part necessary
to repair the problem, or perhaps 2) flight schedules, etc. made it
more efficient for continuing on to Paris after repairs, or even 3)
they might have wanted you to go to a place where the passengers would
be happier waiting. As we know, airline flight planning departments
don’t always take into account only the safety and efficiency of a
flight, but factor in customer satisfaction, i.e. continued revenue,
very highly as well.
We have at least learned more about transoceanic navigation
procedures, if not about the mystery of why your flight was diverted
so far off route to tend to its emergency. I’m sorry I couldn’t help
with that part of it. But in case you’d like to continue on your own
in learning more about global navigation and transoceanic procedures,
here are a few more links for you:
The International Flight Information Manual:
http://www2.faa.gov/ats/aat/ifim/index.htm
Here’s a book that looks interesting: “Global Navigation for Pilots:
($29.95)
http://www.pilotsbooks.com/global_navigation_for_pilots.htm
US Air Force Scientific Advisory Board: Dec. 1997 Report on Global Air
Navigation Systems:
http://www.au.af.mil/au/awc/awcgate/sab/sabgans.pdf
FAA Satellite Navigation Product Teams (Programs – NAS
Implementation):
http://gps.faa.gov/programs/nas/caribbean-text.htm
ICAO North Atlantic Programme Coordination Office:
http://www.nat-pco.org/Monitor.htm
ICAO Main Site:
http://www.icao.int/index.cfm
Very fascinating question. I did indeed answer more than I usually
would for a $5 question, but like it says in the pricing guidelines (
http://answers.google.com/answers/pricing.html ) “sometimes if a
Researcher is personally interested .....!” Again, thanks for the
chance to learn about such an interesting subject. I hope I didn’t
sound too condescending in my original answer, but it’s hard sometimes
to gauge the level of knowledge of the person asking the question. In
your case I needn’t have worried.
All my best,
Byrd
Additional search terms:
atlantic "air navigation" OR "air routes" OR "oceanic routes" OR "Air
tracks"
"south atlantic" "air navigation" OR "air routes" OR "oceanic routes"
OR "Air tracks"
air navigation "north atlantic procedures"
air navigation atlantic routes
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